Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/kernel/exit.c

Diff markup

Differences between /kernel/exit.c (Version 4.10) and /kernel/exit.c (Version 2.6.37)


  1 /*                                                  1 /*
  2  *  linux/kernel/exit.c                             2  *  linux/kernel/exit.c
  3  *                                                  3  *
  4  *  Copyright (C) 1991, 1992  Linus Torvalds        4  *  Copyright (C) 1991, 1992  Linus Torvalds
  5  */                                                 5  */
  6                                                     6 
  7 #include <linux/mm.h>                               7 #include <linux/mm.h>
  8 #include <linux/slab.h>                             8 #include <linux/slab.h>
  9 #include <linux/interrupt.h>                        9 #include <linux/interrupt.h>
 10 #include <linux/module.h>                          10 #include <linux/module.h>
 11 #include <linux/capability.h>                      11 #include <linux/capability.h>
 12 #include <linux/completion.h>                      12 #include <linux/completion.h>
 13 #include <linux/personality.h>                     13 #include <linux/personality.h>
 14 #include <linux/tty.h>                             14 #include <linux/tty.h>
 15 #include <linux/iocontext.h>                       15 #include <linux/iocontext.h>
 16 #include <linux/key.h>                             16 #include <linux/key.h>
 17 #include <linux/security.h>                        17 #include <linux/security.h>
 18 #include <linux/cpu.h>                             18 #include <linux/cpu.h>
 19 #include <linux/acct.h>                            19 #include <linux/acct.h>
 20 #include <linux/tsacct_kern.h>                     20 #include <linux/tsacct_kern.h>
 21 #include <linux/file.h>                            21 #include <linux/file.h>
 22 #include <linux/fdtable.h>                         22 #include <linux/fdtable.h>
 23 #include <linux/freezer.h>                     << 
 24 #include <linux/binfmts.h>                         23 #include <linux/binfmts.h>
 25 #include <linux/nsproxy.h>                         24 #include <linux/nsproxy.h>
 26 #include <linux/pid_namespace.h>                   25 #include <linux/pid_namespace.h>
 27 #include <linux/ptrace.h>                          26 #include <linux/ptrace.h>
 28 #include <linux/profile.h>                         27 #include <linux/profile.h>
 29 #include <linux/mount.h>                           28 #include <linux/mount.h>
 30 #include <linux/proc_fs.h>                         29 #include <linux/proc_fs.h>
 31 #include <linux/kthread.h>                         30 #include <linux/kthread.h>
 32 #include <linux/mempolicy.h>                       31 #include <linux/mempolicy.h>
 33 #include <linux/taskstats_kern.h>                  32 #include <linux/taskstats_kern.h>
 34 #include <linux/delayacct.h>                       33 #include <linux/delayacct.h>
                                                   >>  34 #include <linux/freezer.h>
 35 #include <linux/cgroup.h>                          35 #include <linux/cgroup.h>
 36 #include <linux/syscalls.h>                        36 #include <linux/syscalls.h>
 37 #include <linux/signal.h>                          37 #include <linux/signal.h>
 38 #include <linux/posix-timers.h>                    38 #include <linux/posix-timers.h>
 39 #include <linux/cn_proc.h>                         39 #include <linux/cn_proc.h>
 40 #include <linux/mutex.h>                           40 #include <linux/mutex.h>
 41 #include <linux/futex.h>                           41 #include <linux/futex.h>
 42 #include <linux/pipe_fs_i.h>                       42 #include <linux/pipe_fs_i.h>
 43 #include <linux/audit.h> /* for audit_free() *     43 #include <linux/audit.h> /* for audit_free() */
 44 #include <linux/resource.h>                        44 #include <linux/resource.h>
 45 #include <linux/blkdev.h>                          45 #include <linux/blkdev.h>
 46 #include <linux/task_io_accounting_ops.h>          46 #include <linux/task_io_accounting_ops.h>
 47 #include <linux/tracehook.h>                       47 #include <linux/tracehook.h>
 48 #include <linux/fs_struct.h>                       48 #include <linux/fs_struct.h>
 49 #include <linux/init_task.h>                       49 #include <linux/init_task.h>
 50 #include <linux/perf_event.h>                      50 #include <linux/perf_event.h>
 51 #include <trace/events/sched.h>                    51 #include <trace/events/sched.h>
 52 #include <linux/hw_breakpoint.h>                   52 #include <linux/hw_breakpoint.h>
 53 #include <linux/oom.h>                             53 #include <linux/oom.h>
 54 #include <linux/writeback.h>                   << 
 55 #include <linux/shm.h>                         << 
 56 #include <linux/kcov.h>                        << 
 57 #include <linux/random.h>                      << 
 58                                                    54 
 59 #include <linux/uaccess.h>                     !!  55 #include <asm/uaccess.h>
 60 #include <asm/unistd.h>                            56 #include <asm/unistd.h>
 61 #include <asm/pgtable.h>                           57 #include <asm/pgtable.h>
 62 #include <asm/mmu_context.h>                       58 #include <asm/mmu_context.h>
 63                                                    59 
                                                   >>  60 static void exit_mm(struct task_struct * tsk);
                                                   >>  61 
 64 static void __unhash_process(struct task_struc     62 static void __unhash_process(struct task_struct *p, bool group_dead)
 65 {                                                  63 {
 66         nr_threads--;                              64         nr_threads--;
 67         detach_pid(p, PIDTYPE_PID);                65         detach_pid(p, PIDTYPE_PID);
 68         if (group_dead) {                          66         if (group_dead) {
 69                 detach_pid(p, PIDTYPE_PGID);       67                 detach_pid(p, PIDTYPE_PGID);
 70                 detach_pid(p, PIDTYPE_SID);        68                 detach_pid(p, PIDTYPE_SID);
 71                                                    69 
 72                 list_del_rcu(&p->tasks);           70                 list_del_rcu(&p->tasks);
 73                 list_del_init(&p->sibling);        71                 list_del_init(&p->sibling);
 74                 __this_cpu_dec(process_counts) !!  72                 __get_cpu_var(process_counts)--;
 75         }                                          73         }
 76         list_del_rcu(&p->thread_group);            74         list_del_rcu(&p->thread_group);
 77         list_del_rcu(&p->thread_node);         << 
 78 }                                                  75 }
 79                                                    76 
 80 /*                                                 77 /*
 81  * This function expects the tasklist_lock wri     78  * This function expects the tasklist_lock write-locked.
 82  */                                                79  */
 83 static void __exit_signal(struct task_struct *     80 static void __exit_signal(struct task_struct *tsk)
 84 {                                                  81 {
 85         struct signal_struct *sig = tsk->signa     82         struct signal_struct *sig = tsk->signal;
 86         bool group_dead = thread_group_leader(     83         bool group_dead = thread_group_leader(tsk);
 87         struct sighand_struct *sighand;            84         struct sighand_struct *sighand;
 88         struct tty_struct *uninitialized_var(t     85         struct tty_struct *uninitialized_var(tty);
 89         cputime_t utime, stime;                << 
 90                                                    86 
 91         sighand = rcu_dereference_check(tsk->s     87         sighand = rcu_dereference_check(tsk->sighand,
                                                   >>  88                                         rcu_read_lock_held() ||
 92                                         lockde     89                                         lockdep_tasklist_lock_is_held());
 93         spin_lock(&sighand->siglock);              90         spin_lock(&sighand->siglock);
 94                                                    91 
 95 #ifdef CONFIG_POSIX_TIMERS                     << 
 96         posix_cpu_timers_exit(tsk);                92         posix_cpu_timers_exit(tsk);
 97         if (group_dead) {                          93         if (group_dead) {
 98                 posix_cpu_timers_exit_group(ts     94                 posix_cpu_timers_exit_group(tsk);
                                                   >>  95                 tty = sig->tty;
                                                   >>  96                 sig->tty = NULL;
 99         } else {                                   97         } else {
100                 /*                                 98                 /*
101                  * This can only happen if the     99                  * This can only happen if the caller is de_thread().
102                  * FIXME: this is the temporar    100                  * FIXME: this is the temporary hack, we should teach
103                  * posix-cpu-timers to handle     101                  * posix-cpu-timers to handle this case correctly.
104                  */                               102                  */
105                 if (unlikely(has_group_leader_    103                 if (unlikely(has_group_leader_pid(tsk)))
106                         posix_cpu_timers_exit_    104                         posix_cpu_timers_exit_group(tsk);
107         }                                      << 
108 #endif                                         << 
109                                                   105 
110         if (group_dead) {                      << 
111                 tty = sig->tty;                << 
112                 sig->tty = NULL;               << 
113         } else {                               << 
114                 /*                                106                 /*
115                  * If there is any task waitin    107                  * If there is any task waiting for the group exit
116                  * then notify it:                108                  * then notify it:
117                  */                               109                  */
118                 if (sig->notify_count > 0 && !    110                 if (sig->notify_count > 0 && !--sig->notify_count)
119                         wake_up_process(sig->g    111                         wake_up_process(sig->group_exit_task);
120                                                   112 
121                 if (tsk == sig->curr_target)      113                 if (tsk == sig->curr_target)
122                         sig->curr_target = nex    114                         sig->curr_target = next_thread(tsk);
                                                   >> 115                 /*
                                                   >> 116                  * Accumulate here the counters for all threads but the
                                                   >> 117                  * group leader as they die, so they can be added into
                                                   >> 118                  * the process-wide totals when those are taken.
                                                   >> 119                  * The group leader stays around as a zombie as long
                                                   >> 120                  * as there are other threads.  When it gets reaped,
                                                   >> 121                  * the exit.c code will add its counts into these totals.
                                                   >> 122                  * We won't ever get here for the group leader, since it
                                                   >> 123                  * will have been the last reference on the signal_struct.
                                                   >> 124                  */
                                                   >> 125                 sig->utime = cputime_add(sig->utime, tsk->utime);
                                                   >> 126                 sig->stime = cputime_add(sig->stime, tsk->stime);
                                                   >> 127                 sig->gtime = cputime_add(sig->gtime, tsk->gtime);
                                                   >> 128                 sig->min_flt += tsk->min_flt;
                                                   >> 129                 sig->maj_flt += tsk->maj_flt;
                                                   >> 130                 sig->nvcsw += tsk->nvcsw;
                                                   >> 131                 sig->nivcsw += tsk->nivcsw;
                                                   >> 132                 sig->inblock += task_io_get_inblock(tsk);
                                                   >> 133                 sig->oublock += task_io_get_oublock(tsk);
                                                   >> 134                 task_io_accounting_add(&sig->ioac, &tsk->ioac);
                                                   >> 135                 sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
123         }                                         136         }
124                                                   137 
125         add_device_randomness((const void*) &t << 
126                               sizeof(unsigned  << 
127                                                << 
128         /*                                     << 
129          * Accumulate here the counters for al << 
130          * skip the group leader because it is << 
131          * but we want to avoid the race with  << 
132          * see the empty ->thread_head list.   << 
133          */                                    << 
134         task_cputime(tsk, &utime, &stime);     << 
135         write_seqlock(&sig->stats_lock);       << 
136         sig->utime += utime;                   << 
137         sig->stime += stime;                   << 
138         sig->gtime += task_gtime(tsk);         << 
139         sig->min_flt += tsk->min_flt;          << 
140         sig->maj_flt += tsk->maj_flt;          << 
141         sig->nvcsw += tsk->nvcsw;              << 
142         sig->nivcsw += tsk->nivcsw;            << 
143         sig->inblock += task_io_get_inblock(ts << 
144         sig->oublock += task_io_get_oublock(ts << 
145         task_io_accounting_add(&sig->ioac, &ts << 
146         sig->sum_sched_runtime += tsk->se.sum_ << 
147         sig->nr_threads--;                        138         sig->nr_threads--;
148         __unhash_process(tsk, group_dead);        139         __unhash_process(tsk, group_dead);
149         write_sequnlock(&sig->stats_lock);     << 
150                                                   140 
151         /*                                        141         /*
152          * Do this under ->siglock, we can rac    142          * Do this under ->siglock, we can race with another thread
153          * doing sigqueue_free() if we have SI    143          * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
154          */                                       144          */
155         flush_sigqueue(&tsk->pending);            145         flush_sigqueue(&tsk->pending);
156         tsk->sighand = NULL;                      146         tsk->sighand = NULL;
157         spin_unlock(&sighand->siglock);           147         spin_unlock(&sighand->siglock);
158                                                   148 
159         __cleanup_sighand(sighand);               149         __cleanup_sighand(sighand);
160         clear_tsk_thread_flag(tsk, TIF_SIGPEND !! 150         clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
161         if (group_dead) {                         151         if (group_dead) {
162                 flush_sigqueue(&sig->shared_pe    152                 flush_sigqueue(&sig->shared_pending);
163                 tty_kref_put(tty);                153                 tty_kref_put(tty);
164         }                                         154         }
165 }                                                 155 }
166                                                   156 
167 static void delayed_put_task_struct(struct rcu    157 static void delayed_put_task_struct(struct rcu_head *rhp)
168 {                                                 158 {
169         struct task_struct *tsk = container_of    159         struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
170                                                   160 
171         perf_event_delayed_put(tsk);              161         perf_event_delayed_put(tsk);
172         trace_sched_process_free(tsk);            162         trace_sched_process_free(tsk);
173         put_task_struct(tsk);                     163         put_task_struct(tsk);
174 }                                                 164 }
175                                                   165 
176                                                   166 
177 void release_task(struct task_struct *p)       !! 167 void release_task(struct task_struct * p)
178 {                                                 168 {
179         struct task_struct *leader;               169         struct task_struct *leader;
180         int zap_leader;                           170         int zap_leader;
181 repeat:                                           171 repeat:
                                                   >> 172         tracehook_prepare_release_task(p);
182         /* don't need to get the RCU readlock     173         /* don't need to get the RCU readlock here - the process is dead and
183          * can't be modifying its own credenti    174          * can't be modifying its own credentials. But shut RCU-lockdep up */
184         rcu_read_lock();                          175         rcu_read_lock();
185         atomic_dec(&__task_cred(p)->user->proc    176         atomic_dec(&__task_cred(p)->user->processes);
186         rcu_read_unlock();                        177         rcu_read_unlock();
187                                                   178 
188         proc_flush_task(p);                       179         proc_flush_task(p);
189                                                   180 
190         write_lock_irq(&tasklist_lock);           181         write_lock_irq(&tasklist_lock);
191         ptrace_release_task(p);                !! 182         tracehook_finish_release_task(p);
192         __exit_signal(p);                         183         __exit_signal(p);
193                                                   184 
194         /*                                        185         /*
195          * If we are the last non-leader membe    186          * If we are the last non-leader member of the thread
196          * group, and the leader is zombie, th    187          * group, and the leader is zombie, then notify the
197          * group leader's parent process. (if     188          * group leader's parent process. (if it wants notification.)
198          */                                       189          */
199         zap_leader = 0;                           190         zap_leader = 0;
200         leader = p->group_leader;                 191         leader = p->group_leader;
201         if (leader != p && thread_group_empty( !! 192         if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
202                         && leader->exit_state  !! 193                 BUG_ON(task_detached(leader));
                                                   >> 194                 do_notify_parent(leader, leader->exit_signal);
203                 /*                                195                 /*
204                  * If we were the last child t    196                  * If we were the last child thread and the leader has
205                  * exited already, and the lea    197                  * exited already, and the leader's parent ignores SIGCHLD,
206                  * then we are the one who sho    198                  * then we are the one who should release the leader.
                                                   >> 199                  *
                                                   >> 200                  * do_notify_parent() will have marked it self-reaping in
                                                   >> 201                  * that case.
                                                   >> 202                  */
                                                   >> 203                 zap_leader = task_detached(leader);
                                                   >> 204 
                                                   >> 205                 /*
                                                   >> 206                  * This maintains the invariant that release_task()
                                                   >> 207                  * only runs on a task in EXIT_DEAD, just for sanity.
207                  */                               208                  */
208                 zap_leader = do_notify_parent( << 
209                 if (zap_leader)                   209                 if (zap_leader)
210                         leader->exit_state = E    210                         leader->exit_state = EXIT_DEAD;
211         }                                         211         }
212                                                   212 
213         write_unlock_irq(&tasklist_lock);         213         write_unlock_irq(&tasklist_lock);
214         release_thread(p);                        214         release_thread(p);
215         call_rcu(&p->rcu, delayed_put_task_str    215         call_rcu(&p->rcu, delayed_put_task_struct);
216                                                   216 
217         p = leader;                               217         p = leader;
218         if (unlikely(zap_leader))                 218         if (unlikely(zap_leader))
219                 goto repeat;                      219                 goto repeat;
220 }                                                 220 }
221                                                   221 
222 /*                                                222 /*
223  * Note that if this function returns a valid  !! 223  * This checks not only the pgrp, but falls back on the pid if no
224  * task->usage must remain >0 for the duration !! 224  * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
                                                   >> 225  * without this...
                                                   >> 226  *
                                                   >> 227  * The caller must hold rcu lock or the tasklist lock.
225  */                                               228  */
226 struct task_struct *task_rcu_dereference(struc !! 229 struct pid *session_of_pgrp(struct pid *pgrp)
227 {                                              << 
228         struct sighand_struct *sighand;        << 
229         struct task_struct *task;              << 
230                                                << 
231         /*                                     << 
232          * We need to verify that release_task << 
233          * delayed_put_task_struct() can't run << 
234          * before rcu_read_unlock(). We check  << 
235          * but we can read the already freed a << 
236          */                                    << 
237 retry:                                         << 
238         task = rcu_dereference(*ptask);        << 
239         if (!task)                             << 
240                 return NULL;                   << 
241                                                << 
242         probe_kernel_address(&task->sighand, s << 
243                                                << 
244         /*                                     << 
245          * Pairs with atomic_dec_and_test() in << 
246          * was already freed we can not miss t << 
247          * pointer.                            << 
248          */                                    << 
249         smp_rmb();                             << 
250         if (unlikely(task != READ_ONCE(*ptask) << 
251                 goto retry;                    << 
252                                                << 
253         /*                                     << 
254          * We've re-checked that "task == *pta << 
255          * cases:                              << 
256          *                                     << 
257          * 1. This is actually the same task/t << 
258          *    sighand != NULL tells us it is s << 
259          *                                     << 
260          * 2. This is another task which got t << 
261          *    We can't know this of course, an << 
262          *    sighand != NULL.                 << 
263          *                                     << 
264          *    In this case we actually return  << 
265          *    correct.                         << 
266          *                                     << 
267          *    If we return NULL - we can prete << 
268          *    *ptask was updated when the prev << 
269          *    that probe_slab_address(&sighand << 
270          *                                     << 
271          *    If we return the new task (becau << 
272          *    reason) - this is fine too. This << 
273          *    another gp pass.                 << 
274          *                                     << 
275          *    And note: We could even eliminat << 
276          *    task->sighand once again to avoi << 
277          *    is very unlikely so we don't car << 
278          */                                    << 
279         if (!sighand)                          << 
280                 return NULL;                   << 
281                                                << 
282         return task;                           << 
283 }                                              << 
284                                                << 
285 struct task_struct *try_get_task_struct(struct << 
286 {                                                 230 {
287         struct task_struct *task;              !! 231         struct task_struct *p;
                                                   >> 232         struct pid *sid = NULL;
288                                                   233 
289         rcu_read_lock();                       !! 234         p = pid_task(pgrp, PIDTYPE_PGID);
290         task = task_rcu_dereference(ptask);    !! 235         if (p == NULL)
291         if (task)                              !! 236                 p = pid_task(pgrp, PIDTYPE_PID);
292                 get_task_struct(task);         !! 237         if (p != NULL)
293         rcu_read_unlock();                     !! 238                 sid = task_session(p);
294                                                   239 
295         return task;                           !! 240         return sid;
296 }                                                 241 }
297                                                   242 
298 /*                                                243 /*
299  * Determine if a process group is "orphaned",    244  * Determine if a process group is "orphaned", according to the POSIX
300  * definition in 2.2.2.52.  Orphaned process g    245  * definition in 2.2.2.52.  Orphaned process groups are not to be affected
301  * by terminal-generated stop signals.  Newly     246  * by terminal-generated stop signals.  Newly orphaned process groups are
302  * to receive a SIGHUP and a SIGCONT.             247  * to receive a SIGHUP and a SIGCONT.
303  *                                                248  *
304  * "I ask you, have you ever known what it is     249  * "I ask you, have you ever known what it is to be an orphan?"
305  */                                               250  */
306 static int will_become_orphaned_pgrp(struct pi !! 251 static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task)
307                                         struct << 
308 {                                                 252 {
309         struct task_struct *p;                    253         struct task_struct *p;
310                                                   254 
311         do_each_pid_task(pgrp, PIDTYPE_PGID, p    255         do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
312                 if ((p == ignored_task) ||        256                 if ((p == ignored_task) ||
313                     (p->exit_state && thread_g    257                     (p->exit_state && thread_group_empty(p)) ||
314                     is_global_init(p->real_par    258                     is_global_init(p->real_parent))
315                         continue;                 259                         continue;
316                                                   260 
317                 if (task_pgrp(p->real_parent)     261                 if (task_pgrp(p->real_parent) != pgrp &&
318                     task_session(p->real_paren    262                     task_session(p->real_parent) == task_session(p))
319                         return 0;                 263                         return 0;
320         } while_each_pid_task(pgrp, PIDTYPE_PG    264         } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
321                                                   265 
322         return 1;                                 266         return 1;
323 }                                                 267 }
324                                                   268 
325 int is_current_pgrp_orphaned(void)                269 int is_current_pgrp_orphaned(void)
326 {                                                 270 {
327         int retval;                               271         int retval;
328                                                   272 
329         read_lock(&tasklist_lock);                273         read_lock(&tasklist_lock);
330         retval = will_become_orphaned_pgrp(tas    274         retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
331         read_unlock(&tasklist_lock);              275         read_unlock(&tasklist_lock);
332                                                   276 
333         return retval;                            277         return retval;
334 }                                                 278 }
335                                                   279 
336 static bool has_stopped_jobs(struct pid *pgrp) !! 280 static int has_stopped_jobs(struct pid *pgrp)
337 {                                                 281 {
                                                   >> 282         int retval = 0;
338         struct task_struct *p;                    283         struct task_struct *p;
339                                                   284 
340         do_each_pid_task(pgrp, PIDTYPE_PGID, p    285         do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
341                 if (p->signal->flags & SIGNAL_ !! 286                 if (!task_is_stopped(p))
342                         return true;           !! 287                         continue;
                                                   >> 288                 retval = 1;
                                                   >> 289                 break;
343         } while_each_pid_task(pgrp, PIDTYPE_PG    290         } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
344                                                !! 291         return retval;
345         return false;                          << 
346 }                                                 292 }
347                                                   293 
348 /*                                                294 /*
349  * Check to see if any process groups have bec    295  * Check to see if any process groups have become orphaned as
350  * a result of our exiting, and if they have a    296  * a result of our exiting, and if they have any stopped jobs,
351  * send them a SIGHUP and then a SIGCONT. (POS    297  * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
352  */                                               298  */
353 static void                                       299 static void
354 kill_orphaned_pgrp(struct task_struct *tsk, st    300 kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
355 {                                                 301 {
356         struct pid *pgrp = task_pgrp(tsk);        302         struct pid *pgrp = task_pgrp(tsk);
357         struct task_struct *ignored_task = tsk    303         struct task_struct *ignored_task = tsk;
358                                                   304 
359         if (!parent)                              305         if (!parent)
360                 /* exit: our father is in a di !! 306                  /* exit: our father is in a different pgrp than
361                  * we are and we were the only !! 307                   * we are and we were the only connection outside.
362                  */                            !! 308                   */
363                 parent = tsk->real_parent;        309                 parent = tsk->real_parent;
364         else                                      310         else
365                 /* reparent: our child is in a    311                 /* reparent: our child is in a different pgrp than
366                  * we are, and it was the only    312                  * we are, and it was the only connection outside.
367                  */                               313                  */
368                 ignored_task = NULL;              314                 ignored_task = NULL;
369                                                   315 
370         if (task_pgrp(parent) != pgrp &&          316         if (task_pgrp(parent) != pgrp &&
371             task_session(parent) == task_sessi    317             task_session(parent) == task_session(tsk) &&
372             will_become_orphaned_pgrp(pgrp, ig    318             will_become_orphaned_pgrp(pgrp, ignored_task) &&
373             has_stopped_jobs(pgrp)) {             319             has_stopped_jobs(pgrp)) {
374                 __kill_pgrp_info(SIGHUP, SEND_    320                 __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
375                 __kill_pgrp_info(SIGCONT, SEND    321                 __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
376         }                                         322         }
377 }                                                 323 }
378                                                   324 
379 #ifdef CONFIG_MEMCG                            !! 325 /**
                                                   >> 326  * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
                                                   >> 327  *
                                                   >> 328  * If a kernel thread is launched as a result of a system call, or if
                                                   >> 329  * it ever exits, it should generally reparent itself to kthreadd so it
                                                   >> 330  * isn't in the way of other processes and is correctly cleaned up on exit.
                                                   >> 331  *
                                                   >> 332  * The various task state such as scheduling policy and priority may have
                                                   >> 333  * been inherited from a user process, so we reset them to sane values here.
                                                   >> 334  *
                                                   >> 335  * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
                                                   >> 336  */
                                                   >> 337 static void reparent_to_kthreadd(void)
                                                   >> 338 {
                                                   >> 339         write_lock_irq(&tasklist_lock);
                                                   >> 340 
                                                   >> 341         ptrace_unlink(current);
                                                   >> 342         /* Reparent to init */
                                                   >> 343         current->real_parent = current->parent = kthreadd_task;
                                                   >> 344         list_move_tail(&current->sibling, &current->real_parent->children);
                                                   >> 345 
                                                   >> 346         /* Set the exit signal to SIGCHLD so we signal init on exit */
                                                   >> 347         current->exit_signal = SIGCHLD;
                                                   >> 348 
                                                   >> 349         if (task_nice(current) < 0)
                                                   >> 350                 set_user_nice(current, 0);
                                                   >> 351         /* cpus_allowed? */
                                                   >> 352         /* rt_priority? */
                                                   >> 353         /* signals? */
                                                   >> 354         memcpy(current->signal->rlim, init_task.signal->rlim,
                                                   >> 355                sizeof(current->signal->rlim));
                                                   >> 356 
                                                   >> 357         atomic_inc(&init_cred.usage);
                                                   >> 358         commit_creds(&init_cred);
                                                   >> 359         write_unlock_irq(&tasklist_lock);
                                                   >> 360 }
                                                   >> 361 
                                                   >> 362 void __set_special_pids(struct pid *pid)
                                                   >> 363 {
                                                   >> 364         struct task_struct *curr = current->group_leader;
                                                   >> 365 
                                                   >> 366         if (task_session(curr) != pid)
                                                   >> 367                 change_pid(curr, PIDTYPE_SID, pid);
                                                   >> 368 
                                                   >> 369         if (task_pgrp(curr) != pid)
                                                   >> 370                 change_pid(curr, PIDTYPE_PGID, pid);
                                                   >> 371 }
                                                   >> 372 
                                                   >> 373 static void set_special_pids(struct pid *pid)
                                                   >> 374 {
                                                   >> 375         write_lock_irq(&tasklist_lock);
                                                   >> 376         __set_special_pids(pid);
                                                   >> 377         write_unlock_irq(&tasklist_lock);
                                                   >> 378 }
                                                   >> 379 
380 /*                                                380 /*
381  * A task is exiting.   If it owned this mm, f !! 381  * Let kernel threads use this to say that they allow a certain signal.
                                                   >> 382  * Must not be used if kthread was cloned with CLONE_SIGHAND.
382  */                                               383  */
383 void mm_update_next_owner(struct mm_struct *mm !! 384 int allow_signal(int sig)
384 {                                                 385 {
385         struct task_struct *c, *g, *p = curren !! 386         if (!valid_signal(sig) || sig < 1)
                                                   >> 387                 return -EINVAL;
                                                   >> 388 
                                                   >> 389         spin_lock_irq(&current->sighand->siglock);
                                                   >> 390         /* This is only needed for daemonize()'ed kthreads */
                                                   >> 391         sigdelset(&current->blocked, sig);
                                                   >> 392         /*
                                                   >> 393          * Kernel threads handle their own signals. Let the signal code
                                                   >> 394          * know it'll be handled, so that they don't get converted to
                                                   >> 395          * SIGKILL or just silently dropped.
                                                   >> 396          */
                                                   >> 397         current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
                                                   >> 398         recalc_sigpending();
                                                   >> 399         spin_unlock_irq(&current->sighand->siglock);
                                                   >> 400         return 0;
                                                   >> 401 }
                                                   >> 402 
                                                   >> 403 EXPORT_SYMBOL(allow_signal);
                                                   >> 404 
                                                   >> 405 int disallow_signal(int sig)
                                                   >> 406 {
                                                   >> 407         if (!valid_signal(sig) || sig < 1)
                                                   >> 408                 return -EINVAL;
                                                   >> 409 
                                                   >> 410         spin_lock_irq(&current->sighand->siglock);
                                                   >> 411         current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;
                                                   >> 412         recalc_sigpending();
                                                   >> 413         spin_unlock_irq(&current->sighand->siglock);
                                                   >> 414         return 0;
                                                   >> 415 }
                                                   >> 416 
                                                   >> 417 EXPORT_SYMBOL(disallow_signal);
                                                   >> 418 
                                                   >> 419 /*
                                                   >> 420  *      Put all the gunge required to become a kernel thread without
                                                   >> 421  *      attached user resources in one place where it belongs.
                                                   >> 422  */
                                                   >> 423 
                                                   >> 424 void daemonize(const char *name, ...)
                                                   >> 425 {
                                                   >> 426         va_list args;
                                                   >> 427         sigset_t blocked;
                                                   >> 428 
                                                   >> 429         va_start(args, name);
                                                   >> 430         vsnprintf(current->comm, sizeof(current->comm), name, args);
                                                   >> 431         va_end(args);
386                                                   432 
387 retry:                                         << 
388         /*                                        433         /*
389          * If the exiting or execing task is n !! 434          * If we were started as result of loading a module, close all of the
390          * someone else's problem.             !! 435          * user space pages.  We don't need them, and if we didn't close them
                                                   >> 436          * they would be locked into memory.
391          */                                       437          */
392         if (mm->owner != p)                    !! 438         exit_mm(current);
393                 return;                        << 
394         /*                                        439         /*
395          * The current owner is exiting/execin !! 440          * We don't want to have TIF_FREEZE set if the system-wide hibernation
396          * candidates.  Do not leave the mm po !! 441          * or suspend transition begins right now.
397          * freed task structure.               << 
398          */                                       442          */
399         if (atomic_read(&mm->mm_users) <= 1) { !! 443         current->flags |= (PF_NOFREEZE | PF_KTHREAD);
400                 mm->owner = NULL;              !! 444 
401                 return;                        !! 445         if (current->nsproxy != &init_nsproxy) {
                                                   >> 446                 get_nsproxy(&init_nsproxy);
                                                   >> 447                 switch_task_namespaces(current, &init_nsproxy);
402         }                                         448         }
                                                   >> 449         set_special_pids(&init_struct_pid);
                                                   >> 450         proc_clear_tty(current);
                                                   >> 451 
                                                   >> 452         /* Block and flush all signals */
                                                   >> 453         sigfillset(&blocked);
                                                   >> 454         sigprocmask(SIG_BLOCK, &blocked, NULL);
                                                   >> 455         flush_signals(current);
                                                   >> 456 
                                                   >> 457         /* Become as one with the init task */
                                                   >> 458 
                                                   >> 459         daemonize_fs_struct();
                                                   >> 460         exit_files(current);
                                                   >> 461         current->files = init_task.files;
                                                   >> 462         atomic_inc(&current->files->count);
                                                   >> 463 
                                                   >> 464         reparent_to_kthreadd();
                                                   >> 465 }
                                                   >> 466 
                                                   >> 467 EXPORT_SYMBOL(daemonize);
                                                   >> 468 
                                                   >> 469 static void close_files(struct files_struct * files)
                                                   >> 470 {
                                                   >> 471         int i, j;
                                                   >> 472         struct fdtable *fdt;
                                                   >> 473 
                                                   >> 474         j = 0;
                                                   >> 475 
                                                   >> 476         /*
                                                   >> 477          * It is safe to dereference the fd table without RCU or
                                                   >> 478          * ->file_lock because this is the last reference to the
                                                   >> 479          * files structure.  But use RCU to shut RCU-lockdep up.
                                                   >> 480          */
                                                   >> 481         rcu_read_lock();
                                                   >> 482         fdt = files_fdtable(files);
                                                   >> 483         rcu_read_unlock();
                                                   >> 484         for (;;) {
                                                   >> 485                 unsigned long set;
                                                   >> 486                 i = j * __NFDBITS;
                                                   >> 487                 if (i >= fdt->max_fds)
                                                   >> 488                         break;
                                                   >> 489                 set = fdt->open_fds->fds_bits[j++];
                                                   >> 490                 while (set) {
                                                   >> 491                         if (set & 1) {
                                                   >> 492                                 struct file * file = xchg(&fdt->fd[i], NULL);
                                                   >> 493                                 if (file) {
                                                   >> 494                                         filp_close(file, files);
                                                   >> 495                                         cond_resched();
                                                   >> 496                                 }
                                                   >> 497                         }
                                                   >> 498                         i++;
                                                   >> 499                         set >>= 1;
                                                   >> 500                 }
                                                   >> 501         }
                                                   >> 502 }
                                                   >> 503 
                                                   >> 504 struct files_struct *get_files_struct(struct task_struct *task)
                                                   >> 505 {
                                                   >> 506         struct files_struct *files;
                                                   >> 507 
                                                   >> 508         task_lock(task);
                                                   >> 509         files = task->files;
                                                   >> 510         if (files)
                                                   >> 511                 atomic_inc(&files->count);
                                                   >> 512         task_unlock(task);
                                                   >> 513 
                                                   >> 514         return files;
                                                   >> 515 }
                                                   >> 516 
                                                   >> 517 void put_files_struct(struct files_struct *files)
                                                   >> 518 {
                                                   >> 519         struct fdtable *fdt;
                                                   >> 520 
                                                   >> 521         if (atomic_dec_and_test(&files->count)) {
                                                   >> 522                 close_files(files);
                                                   >> 523                 /*
                                                   >> 524                  * Free the fd and fdset arrays if we expanded them.
                                                   >> 525                  * If the fdtable was embedded, pass files for freeing
                                                   >> 526                  * at the end of the RCU grace period. Otherwise,
                                                   >> 527                  * you can free files immediately.
                                                   >> 528                  */
                                                   >> 529                 rcu_read_lock();
                                                   >> 530                 fdt = files_fdtable(files);
                                                   >> 531                 if (fdt != &files->fdtab)
                                                   >> 532                         kmem_cache_free(files_cachep, files);
                                                   >> 533                 free_fdtable(fdt);
                                                   >> 534                 rcu_read_unlock();
                                                   >> 535         }
                                                   >> 536 }
                                                   >> 537 
                                                   >> 538 void reset_files_struct(struct files_struct *files)
                                                   >> 539 {
                                                   >> 540         struct task_struct *tsk = current;
                                                   >> 541         struct files_struct *old;
                                                   >> 542 
                                                   >> 543         old = tsk->files;
                                                   >> 544         task_lock(tsk);
                                                   >> 545         tsk->files = files;
                                                   >> 546         task_unlock(tsk);
                                                   >> 547         put_files_struct(old);
                                                   >> 548 }
                                                   >> 549 
                                                   >> 550 void exit_files(struct task_struct *tsk)
                                                   >> 551 {
                                                   >> 552         struct files_struct * files = tsk->files;
                                                   >> 553 
                                                   >> 554         if (files) {
                                                   >> 555                 task_lock(tsk);
                                                   >> 556                 tsk->files = NULL;
                                                   >> 557                 task_unlock(tsk);
                                                   >> 558                 put_files_struct(files);
                                                   >> 559         }
                                                   >> 560 }
                                                   >> 561 
                                                   >> 562 #ifdef CONFIG_MM_OWNER
                                                   >> 563 /*
                                                   >> 564  * Task p is exiting and it owned mm, lets find a new owner for it
                                                   >> 565  */
                                                   >> 566 static inline int
                                                   >> 567 mm_need_new_owner(struct mm_struct *mm, struct task_struct *p)
                                                   >> 568 {
                                                   >> 569         /*
                                                   >> 570          * If there are other users of the mm and the owner (us) is exiting
                                                   >> 571          * we need to find a new owner to take on the responsibility.
                                                   >> 572          */
                                                   >> 573         if (atomic_read(&mm->mm_users) <= 1)
                                                   >> 574                 return 0;
                                                   >> 575         if (mm->owner != p)
                                                   >> 576                 return 0;
                                                   >> 577         return 1;
                                                   >> 578 }
                                                   >> 579 
                                                   >> 580 void mm_update_next_owner(struct mm_struct *mm)
                                                   >> 581 {
                                                   >> 582         struct task_struct *c, *g, *p = current;
                                                   >> 583 
                                                   >> 584 retry:
                                                   >> 585         if (!mm_need_new_owner(mm, p))
                                                   >> 586                 return;
403                                                   587 
404         read_lock(&tasklist_lock);                588         read_lock(&tasklist_lock);
405         /*                                        589         /*
406          * Search in the children                 590          * Search in the children
407          */                                       591          */
408         list_for_each_entry(c, &p->children, s    592         list_for_each_entry(c, &p->children, sibling) {
409                 if (c->mm == mm)                  593                 if (c->mm == mm)
410                         goto assign_new_owner;    594                         goto assign_new_owner;
411         }                                         595         }
412                                                   596 
413         /*                                        597         /*
414          * Search in the siblings                 598          * Search in the siblings
415          */                                       599          */
416         list_for_each_entry(c, &p->real_parent    600         list_for_each_entry(c, &p->real_parent->children, sibling) {
417                 if (c->mm == mm)                  601                 if (c->mm == mm)
418                         goto assign_new_owner;    602                         goto assign_new_owner;
419         }                                         603         }
420                                                   604 
421         /*                                        605         /*
422          * Search through everything else, we  !! 606          * Search through everything else. We should not get
                                                   >> 607          * here often
423          */                                       608          */
424         for_each_process(g) {                  !! 609         do_each_thread(g, c) {
425                 if (g->flags & PF_KTHREAD)     !! 610                 if (c->mm == mm)
426                         continue;              !! 611                         goto assign_new_owner;
427                 for_each_thread(g, c) {        !! 612         } while_each_thread(g, c);
428                         if (c->mm == mm)       !! 613 
429                                 goto assign_ne << 
430                         if (c->mm)             << 
431                                 break;         << 
432                 }                              << 
433         }                                      << 
434         read_unlock(&tasklist_lock);              614         read_unlock(&tasklist_lock);
435         /*                                        615         /*
436          * We found no owner yet mm_users > 1:    616          * We found no owner yet mm_users > 1: this implies that we are
437          * most likely racing with swapoff (tr    617          * most likely racing with swapoff (try_to_unuse()) or /proc or
438          * ptrace or page migration (get_task_    618          * ptrace or page migration (get_task_mm()).  Mark owner as NULL.
439          */                                       619          */
440         mm->owner = NULL;                         620         mm->owner = NULL;
441         return;                                   621         return;
442                                                   622 
443 assign_new_owner:                                 623 assign_new_owner:
444         BUG_ON(c == p);                           624         BUG_ON(c == p);
445         get_task_struct(c);                       625         get_task_struct(c);
446         /*                                        626         /*
447          * The task_lock protects c->mm from c    627          * The task_lock protects c->mm from changing.
448          * We always want mm->owner->mm == mm     628          * We always want mm->owner->mm == mm
449          */                                       629          */
450         task_lock(c);                             630         task_lock(c);
451         /*                                        631         /*
452          * Delay read_unlock() till we have th    632          * Delay read_unlock() till we have the task_lock()
453          * to ensure that c does not slip away    633          * to ensure that c does not slip away underneath us
454          */                                       634          */
455         read_unlock(&tasklist_lock);              635         read_unlock(&tasklist_lock);
456         if (c->mm != mm) {                        636         if (c->mm != mm) {
457                 task_unlock(c);                   637                 task_unlock(c);
458                 put_task_struct(c);               638                 put_task_struct(c);
459                 goto retry;                       639                 goto retry;
460         }                                         640         }
461         mm->owner = c;                            641         mm->owner = c;
462         task_unlock(c);                           642         task_unlock(c);
463         put_task_struct(c);                       643         put_task_struct(c);
464 }                                                 644 }
465 #endif /* CONFIG_MEMCG */                      !! 645 #endif /* CONFIG_MM_OWNER */
466                                                   646 
467 /*                                                647 /*
468  * Turn us into a lazy TLB process if we          648  * Turn us into a lazy TLB process if we
469  * aren't already..                               649  * aren't already..
470  */                                               650  */
471 static void exit_mm(struct task_struct *tsk)   !! 651 static void exit_mm(struct task_struct * tsk)
472 {                                                 652 {
473         struct mm_struct *mm = tsk->mm;           653         struct mm_struct *mm = tsk->mm;
474         struct core_state *core_state;            654         struct core_state *core_state;
475                                                   655 
476         mm_release(tsk, mm);                      656         mm_release(tsk, mm);
477         if (!mm)                                  657         if (!mm)
478                 return;                           658                 return;
479         sync_mm_rss(mm);                       << 
480         /*                                        659         /*
481          * Serialize with any possible pending    660          * Serialize with any possible pending coredump.
482          * We must hold mmap_sem around checki    661          * We must hold mmap_sem around checking core_state
483          * and clearing tsk->mm.  The core-ind    662          * and clearing tsk->mm.  The core-inducing thread
484          * will increment ->nr_threads for eac    663          * will increment ->nr_threads for each thread in the
485          * group with ->mm != NULL.               664          * group with ->mm != NULL.
486          */                                       665          */
487         down_read(&mm->mmap_sem);                 666         down_read(&mm->mmap_sem);
488         core_state = mm->core_state;              667         core_state = mm->core_state;
489         if (core_state) {                         668         if (core_state) {
490                 struct core_thread self;          669                 struct core_thread self;
491                                                << 
492                 up_read(&mm->mmap_sem);           670                 up_read(&mm->mmap_sem);
493                                                   671 
494                 self.task = tsk;                  672                 self.task = tsk;
495                 self.next = xchg(&core_state->    673                 self.next = xchg(&core_state->dumper.next, &self);
496                 /*                                674                 /*
497                  * Implies mb(), the result of    675                  * Implies mb(), the result of xchg() must be visible
498                  * to core_state->dumper.         676                  * to core_state->dumper.
499                  */                               677                  */
500                 if (atomic_dec_and_test(&core_    678                 if (atomic_dec_and_test(&core_state->nr_threads))
501                         complete(&core_state->    679                         complete(&core_state->startup);
502                                                   680 
503                 for (;;) {                        681                 for (;;) {
504                         set_task_state(tsk, TA    682                         set_task_state(tsk, TASK_UNINTERRUPTIBLE);
505                         if (!self.task) /* see    683                         if (!self.task) /* see coredump_finish() */
506                                 break;            684                                 break;
507                         freezable_schedule();  !! 685                         schedule();
508                 }                                 686                 }
509                 __set_task_state(tsk, TASK_RUN    687                 __set_task_state(tsk, TASK_RUNNING);
510                 down_read(&mm->mmap_sem);         688                 down_read(&mm->mmap_sem);
511         }                                         689         }
512         atomic_inc(&mm->mm_count);                690         atomic_inc(&mm->mm_count);
513         BUG_ON(mm != tsk->active_mm);             691         BUG_ON(mm != tsk->active_mm);
514         /* more a memory barrier than a real l    692         /* more a memory barrier than a real lock */
515         task_lock(tsk);                           693         task_lock(tsk);
516         tsk->mm = NULL;                           694         tsk->mm = NULL;
517         up_read(&mm->mmap_sem);                   695         up_read(&mm->mmap_sem);
518         enter_lazy_tlb(mm, current);              696         enter_lazy_tlb(mm, current);
                                                   >> 697         /* We don't want this task to be frozen prematurely */
                                                   >> 698         clear_freeze_flag(tsk);
                                                   >> 699         if (tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
                                                   >> 700                 atomic_dec(&mm->oom_disable_count);
519         task_unlock(tsk);                         701         task_unlock(tsk);
520         mm_update_next_owner(mm);                 702         mm_update_next_owner(mm);
521         mmput(mm);                                703         mmput(mm);
522         if (test_thread_flag(TIF_MEMDIE))      << 
523                 exit_oom_victim();             << 
524 }                                              << 
525                                                << 
526 static struct task_struct *find_alive_thread(s << 
527 {                                              << 
528         struct task_struct *t;                 << 
529                                                << 
530         for_each_thread(p, t) {                << 
531                 if (!(t->flags & PF_EXITING))  << 
532                         return t;              << 
533         }                                      << 
534         return NULL;                           << 
535 }                                                 704 }
536                                                   705 
537 static struct task_struct *find_child_reaper(s !! 706 /*
                                                   >> 707  * When we die, we re-parent all our children.
                                                   >> 708  * Try to give them to another thread in our thread
                                                   >> 709  * group, and if no such member exists, give it to
                                                   >> 710  * the child reaper process (ie "init") in our pid
                                                   >> 711  * space.
                                                   >> 712  */
                                                   >> 713 static struct task_struct *find_new_reaper(struct task_struct *father)
538         __releases(&tasklist_lock)                714         __releases(&tasklist_lock)
539         __acquires(&tasklist_lock)                715         __acquires(&tasklist_lock)
540 {                                                 716 {
541         struct pid_namespace *pid_ns = task_ac    717         struct pid_namespace *pid_ns = task_active_pid_ns(father);
542         struct task_struct *reaper = pid_ns->c !! 718         struct task_struct *thread;
543                                                << 
544         if (likely(reaper != father))          << 
545                 return reaper;                 << 
546                                                << 
547         reaper = find_alive_thread(father);    << 
548         if (reaper) {                          << 
549                 pid_ns->child_reaper = reaper; << 
550                 return reaper;                 << 
551         }                                      << 
552                                                   719 
553         write_unlock_irq(&tasklist_lock);      !! 720         thread = father;
554         if (unlikely(pid_ns == &init_pid_ns))  !! 721         while_each_thread(father, thread) {
555                 panic("Attempted to kill init! !! 722                 if (thread->flags & PF_EXITING)
556                         father->signal->group_ !! 723                         continue;
                                                   >> 724                 if (unlikely(pid_ns->child_reaper == father))
                                                   >> 725                         pid_ns->child_reaper = thread;
                                                   >> 726                 return thread;
557         }                                         727         }
558         zap_pid_ns_processes(pid_ns);          << 
559         write_lock_irq(&tasklist_lock);        << 
560                                                   728 
561         return father;                         !! 729         if (unlikely(pid_ns->child_reaper == father)) {
562 }                                              !! 730                 write_unlock_irq(&tasklist_lock);
563                                                !! 731                 if (unlikely(pid_ns == &init_pid_ns))
564 /*                                             !! 732                         panic("Attempted to kill init!");
565  * When we die, we re-parent all our children, << 
566  * 1. give them to another thread in our threa << 
567  * 2. give it to the first ancestor process wh << 
568  *    child_subreaper for its children (like a << 
569  * 3. give it to the init process (PID 1) in o << 
570  */                                            << 
571 static struct task_struct *find_new_reaper(str << 
572                                            str << 
573 {                                              << 
574         struct task_struct *thread, *reaper;   << 
575                                                << 
576         thread = find_alive_thread(father);    << 
577         if (thread)                            << 
578                 return thread;                 << 
579                                                   733 
580         if (father->signal->has_child_subreape !! 734                 zap_pid_ns_processes(pid_ns);
                                                   >> 735                 write_lock_irq(&tasklist_lock);
581                 /*                                736                 /*
582                  * Find the first ->is_child_s !! 737                  * We can not clear ->child_reaper or leave it alone.
583                  * We start from father to ens !! 738                  * There may by stealth EXIT_DEAD tasks on ->children,
584                  * namespace, this is safe bec !! 739                  * forget_original_parent() must move them somewhere.
585                  */                               740                  */
586                 for (reaper = father;          !! 741                 pid_ns->child_reaper = init_pid_ns.child_reaper;
587                      !same_thread_group(reaper << 
588                      reaper = reaper->real_par << 
589                         /* call_usermodehelper << 
590                         if (reaper == &init_ta << 
591                                 break;         << 
592                         if (!reaper->signal->i << 
593                                 continue;      << 
594                         thread = find_alive_th << 
595                         if (thread)            << 
596                                 return thread; << 
597                 }                              << 
598         }                                         742         }
599                                                   743 
600         return child_reaper;                   !! 744         return pid_ns->child_reaper;
601 }                                                 745 }
602                                                   746 
603 /*                                                747 /*
604 * Any that need to be release_task'd are put o    748 * Any that need to be release_task'd are put on the @dead list.
605  */                                               749  */
606 static void reparent_leader(struct task_struct    750 static void reparent_leader(struct task_struct *father, struct task_struct *p,
607                                 struct list_he    751                                 struct list_head *dead)
608 {                                                 752 {
609         if (unlikely(p->exit_state == EXIT_DEA !! 753         list_move_tail(&p->sibling, &p->real_parent->children);
                                                   >> 754 
                                                   >> 755         if (task_detached(p))
                                                   >> 756                 return;
                                                   >> 757         /*
                                                   >> 758          * If this is a threaded reparent there is no need to
                                                   >> 759          * notify anyone anything has happened.
                                                   >> 760          */
                                                   >> 761         if (same_thread_group(p->real_parent, father))
610                 return;                           762                 return;
611                                                   763 
612         /* We don't want people slaying init.  !! 764         /* We don't want people slaying init.  */
613         p->exit_signal = SIGCHLD;                 765         p->exit_signal = SIGCHLD;
614                                                   766 
615         /* If it has exited notify the new par    767         /* If it has exited notify the new parent about this child's death. */
616         if (!p->ptrace &&                      !! 768         if (!task_ptrace(p) &&
617             p->exit_state == EXIT_ZOMBIE && th    769             p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
618                 if (do_notify_parent(p, p->exi !! 770                 do_notify_parent(p, p->exit_signal);
                                                   >> 771                 if (task_detached(p)) {
619                         p->exit_state = EXIT_D    772                         p->exit_state = EXIT_DEAD;
620                         list_add(&p->ptrace_en !! 773                         list_move_tail(&p->sibling, dead);
621                 }                                 774                 }
622         }                                         775         }
623                                                   776 
624         kill_orphaned_pgrp(p, father);            777         kill_orphaned_pgrp(p, father);
625 }                                                 778 }
626                                                   779 
627 /*                                             !! 780 static void forget_original_parent(struct task_struct *father)
628  * This does two things:                       << 
629  *                                             << 
630  * A.  Make init inherit all the child process << 
631  * B.  Check to see if any process groups have << 
632  *      as a result of our exiting, and if the << 
633  *      jobs, send them a SIGHUP and then a SI << 
634  */                                            << 
635 static void forget_original_parent(struct task << 
636                                         struct << 
637 {                                                 781 {
638         struct task_struct *p, *t, *reaper;    !! 782         struct task_struct *p, *n, *reaper;
639                                                !! 783         LIST_HEAD(dead_children);
640         if (unlikely(!list_empty(&father->ptra << 
641                 exit_ptrace(father, dead);     << 
642                                                   784 
643         /* Can drop and reacquire tasklist_loc !! 785         write_lock_irq(&tasklist_lock);
644         reaper = find_child_reaper(father);    !! 786         /*
645         if (list_empty(&father->children))     !! 787          * Note that exit_ptrace() and find_new_reaper() might
646                 return;                        !! 788          * drop tasklist_lock and reacquire it.
                                                   >> 789          */
                                                   >> 790         exit_ptrace(father);
                                                   >> 791         reaper = find_new_reaper(father);
647                                                   792 
648         reaper = find_new_reaper(father, reape !! 793         list_for_each_entry_safe(p, n, &father->children, sibling) {
649         list_for_each_entry(p, &father->childr !! 794                 struct task_struct *t = p;
650                 for_each_thread(p, t) {        !! 795                 do {
651                         t->real_parent = reape    796                         t->real_parent = reaper;
652                         BUG_ON((!t->ptrace) != !! 797                         if (t->parent == father) {
653                         if (likely(!t->ptrace) !! 798                                 BUG_ON(task_ptrace(t));
654                                 t->parent = t-    799                                 t->parent = t->real_parent;
                                                   >> 800                         }
655                         if (t->pdeath_signal)     801                         if (t->pdeath_signal)
656                                 group_send_sig    802                                 group_send_sig_info(t->pdeath_signal,
657                                                   803                                                     SEND_SIG_NOINFO, t);
658                 }                              !! 804                 } while_each_thread(p, t);
659                 /*                             !! 805                 reparent_leader(father, p, &dead_children);
660                  * If this is a threaded repar !! 806         }
661                  * notify anyone anything has  !! 807         write_unlock_irq(&tasklist_lock);
662                  */                            !! 808 
663                 if (!same_thread_group(reaper, !! 809         BUG_ON(!list_empty(&father->children));
664                         reparent_leader(father !! 810 
                                                   >> 811         list_for_each_entry_safe(p, n, &dead_children, sibling) {
                                                   >> 812                 list_del_init(&p->sibling);
                                                   >> 813                 release_task(p);
665         }                                         814         }
666         list_splice_tail_init(&father->childre << 
667 }                                                 815 }
668                                                   816 
669 /*                                                817 /*
670  * Send signals to all our closest relatives s    818  * Send signals to all our closest relatives so that they know
671  * to properly mourn us..                         819  * to properly mourn us..
672  */                                               820  */
673 static void exit_notify(struct task_struct *ts    821 static void exit_notify(struct task_struct *tsk, int group_dead)
674 {                                                 822 {
675         bool autoreap;                         !! 823         int signal;
676         struct task_struct *p, *n;             !! 824         void *cookie;
677         LIST_HEAD(dead);                       << 
678                                                   825 
679         write_lock_irq(&tasklist_lock);        !! 826         /*
680         forget_original_parent(tsk, &dead);    !! 827          * This does two things:
                                                   >> 828          *
                                                   >> 829          * A.  Make init inherit all the child processes
                                                   >> 830          * B.  Check to see if any process groups have become orphaned
                                                   >> 831          *      as a result of our exiting, and if they have any stopped
                                                   >> 832          *      jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
                                                   >> 833          */
                                                   >> 834         forget_original_parent(tsk);
                                                   >> 835         exit_task_namespaces(tsk);
681                                                   836 
                                                   >> 837         write_lock_irq(&tasklist_lock);
682         if (group_dead)                           838         if (group_dead)
683                 kill_orphaned_pgrp(tsk->group_    839                 kill_orphaned_pgrp(tsk->group_leader, NULL);
684                                                   840 
685         if (unlikely(tsk->ptrace)) {           !! 841         /* Let father know we died
686                 int sig = thread_group_leader( !! 842          *
687                                 thread_group_e !! 843          * Thread signals are configurable, but you aren't going to use
688                                 !ptrace_repare !! 844          * that to send signals to arbitary processes.
689                         tsk->exit_signal : SIG !! 845          * That stops right now.
690                 autoreap = do_notify_parent(ts !! 846          *
691         } else if (thread_group_leader(tsk)) { !! 847          * If the parent exec id doesn't match the exec id we saved
692                 autoreap = thread_group_empty( !! 848          * when we started then we know the parent has changed security
693                         do_notify_parent(tsk,  !! 849          * domain.
694         } else {                               !! 850          *
695                 autoreap = true;               !! 851          * If our self_exec id doesn't match our parent_exec_id then
696         }                                      !! 852          * we have changed execution domain as these two values started
                                                   >> 853          * the same after a fork.
                                                   >> 854          */
                                                   >> 855         if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
                                                   >> 856             (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
                                                   >> 857              tsk->self_exec_id != tsk->parent_exec_id))
                                                   >> 858                 tsk->exit_signal = SIGCHLD;
                                                   >> 859 
                                                   >> 860         signal = tracehook_notify_death(tsk, &cookie, group_dead);
                                                   >> 861         if (signal >= 0)
                                                   >> 862                 signal = do_notify_parent(tsk, signal);
697                                                   863 
698         tsk->exit_state = autoreap ? EXIT_DEAD !! 864         tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
699         if (tsk->exit_state == EXIT_DEAD)      << 
700                 list_add(&tsk->ptrace_entry, & << 
701                                                   865 
702         /* mt-exec, de_thread() is waiting for    866         /* mt-exec, de_thread() is waiting for group leader */
703         if (unlikely(tsk->signal->notify_count    867         if (unlikely(tsk->signal->notify_count < 0))
704                 wake_up_process(tsk->signal->g    868                 wake_up_process(tsk->signal->group_exit_task);
705         write_unlock_irq(&tasklist_lock);         869         write_unlock_irq(&tasklist_lock);
706                                                   870 
707         list_for_each_entry_safe(p, n, &dead,  !! 871         tracehook_report_death(tsk, signal, cookie, group_dead);
708                 list_del_init(&p->ptrace_entry !! 872 
709                 release_task(p);               !! 873         /* If the process is dead, release it - nobody will wait for it */
710         }                                      !! 874         if (signal == DEATH_REAP)
                                                   >> 875                 release_task(tsk);
711 }                                                 876 }
712                                                   877 
713 #ifdef CONFIG_DEBUG_STACK_USAGE                   878 #ifdef CONFIG_DEBUG_STACK_USAGE
714 static void check_stack_usage(void)               879 static void check_stack_usage(void)
715 {                                                 880 {
716         static DEFINE_SPINLOCK(low_water_lock)    881         static DEFINE_SPINLOCK(low_water_lock);
717         static int lowest_to_date = THREAD_SIZ    882         static int lowest_to_date = THREAD_SIZE;
718         unsigned long free;                       883         unsigned long free;
719                                                   884 
720         free = stack_not_used(current);           885         free = stack_not_used(current);
721                                                   886 
722         if (free >= lowest_to_date)               887         if (free >= lowest_to_date)
723                 return;                           888                 return;
724                                                   889 
725         spin_lock(&low_water_lock);               890         spin_lock(&low_water_lock);
726         if (free < lowest_to_date) {              891         if (free < lowest_to_date) {
727                 pr_info("%s (%d) used greatest !! 892                 printk(KERN_WARNING "%s used greatest stack depth: %lu bytes "
728                         current->comm, task_pi !! 893                                 "left\n",
                                                   >> 894                                 current->comm, free);
729                 lowest_to_date = free;            895                 lowest_to_date = free;
730         }                                         896         }
731         spin_unlock(&low_water_lock);             897         spin_unlock(&low_water_lock);
732 }                                                 898 }
733 #else                                             899 #else
734 static inline void check_stack_usage(void) {}     900 static inline void check_stack_usage(void) {}
735 #endif                                            901 #endif
736                                                   902 
737 void __noreturn do_exit(long code)             !! 903 NORET_TYPE void do_exit(long code)
738 {                                                 904 {
739         struct task_struct *tsk = current;        905         struct task_struct *tsk = current;
740         int group_dead;                           906         int group_dead;
741         TASKS_RCU(int tasks_rcu_i);            << 
742                                                   907 
743         profile_task_exit(tsk);                   908         profile_task_exit(tsk);
744         kcov_task_exit(tsk);                   << 
745                                                   909 
746         WARN_ON(blk_needs_flush_plug(tsk));    !! 910         WARN_ON(atomic_read(&tsk->fs_excl));
747                                                   911 
748         if (unlikely(in_interrupt()))             912         if (unlikely(in_interrupt()))
749                 panic("Aiee, killing interrupt    913                 panic("Aiee, killing interrupt handler!");
750         if (unlikely(!tsk->pid))                  914         if (unlikely(!tsk->pid))
751                 panic("Attempted to kill the i    915                 panic("Attempted to kill the idle task!");
752                                                   916 
753         /*                                        917         /*
754          * If do_exit is called because this p    918          * If do_exit is called because this processes oopsed, it's possible
755          * that get_fs() was left as KERNEL_DS    919          * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
756          * continuing. Amongst other possible     920          * continuing. Amongst other possible reasons, this is to prevent
757          * mm_release()->clear_child_tid() fro    921          * mm_release()->clear_child_tid() from writing to a user-controlled
758          * kernel address.                        922          * kernel address.
759          */                                       923          */
760         set_fs(USER_DS);                          924         set_fs(USER_DS);
761                                                   925 
762         ptrace_event(PTRACE_EVENT_EXIT, code); !! 926         tracehook_report_exit(&code);
763                                                   927 
764         validate_creds_for_do_exit(tsk);          928         validate_creds_for_do_exit(tsk);
765                                                   929 
766         /*                                        930         /*
767          * We're taking recursive faults here     931          * We're taking recursive faults here in do_exit. Safest is to just
768          * leave this task alone and wait for     932          * leave this task alone and wait for reboot.
769          */                                       933          */
770         if (unlikely(tsk->flags & PF_EXITING))    934         if (unlikely(tsk->flags & PF_EXITING)) {
771                 pr_alert("Fixing recursive fau !! 935                 printk(KERN_ALERT
                                                   >> 936                         "Fixing recursive fault but reboot is needed!\n");
772                 /*                                937                 /*
773                  * We can do this unlocked her    938                  * We can do this unlocked here. The futex code uses
774                  * this flag just to verify wh    939                  * this flag just to verify whether the pi state
775                  * cleanup has been done or no    940                  * cleanup has been done or not. In the worst case it
776                  * loops once more. We pretend    941                  * loops once more. We pretend that the cleanup was
777                  * done as there is no way to     942                  * done as there is no way to return. Either the
778                  * OWNER_DIED bit is set by no    943                  * OWNER_DIED bit is set by now or we push the blocked
779                  * task into the wait for ever    944                  * task into the wait for ever nirwana as well.
780                  */                               945                  */
781                 tsk->flags |= PF_EXITPIDONE;      946                 tsk->flags |= PF_EXITPIDONE;
782                 set_current_state(TASK_UNINTER    947                 set_current_state(TASK_UNINTERRUPTIBLE);
783                 schedule();                       948                 schedule();
784         }                                         949         }
785                                                   950 
                                                   >> 951         exit_irq_thread();
                                                   >> 952 
786         exit_signals(tsk);  /* sets PF_EXITING    953         exit_signals(tsk);  /* sets PF_EXITING */
787         /*                                        954         /*
788          * Ensure that all new tsk->pi_lock ac !! 955          * tsk->flags are checked in the futex code to protect against
789          * PF_EXITING. Serializes against fute !! 956          * an exiting task cleaning up the robust pi futexes.
790          */                                       957          */
791         smp_mb();                                 958         smp_mb();
792         /*                                     << 
793          * Ensure that we must observe the pi_ << 
794          * mm_release() -> exit_pi_state_list( << 
795          */                                    << 
796         raw_spin_unlock_wait(&tsk->pi_lock);      959         raw_spin_unlock_wait(&tsk->pi_lock);
797                                                   960 
798         if (unlikely(in_atomic())) {           !! 961         if (unlikely(in_atomic()))
799                 pr_info("note: %s[%d] exited w !! 962                 printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
800                         current->comm, task_pi !! 963                                 current->comm, task_pid_nr(current),
801                         preempt_count());      !! 964                                 preempt_count());
802                 preempt_count_set(PREEMPT_ENAB << 
803         }                                      << 
804                                                   965 
                                                   >> 966         acct_update_integrals(tsk);
805         /* sync mm's RSS info before statistic    967         /* sync mm's RSS info before statistics gathering */
806         if (tsk->mm)                              968         if (tsk->mm)
807                 sync_mm_rss(tsk->mm);          !! 969                 sync_mm_rss(tsk, tsk->mm);
808         acct_update_integrals(tsk);            << 
809         group_dead = atomic_dec_and_test(&tsk-    970         group_dead = atomic_dec_and_test(&tsk->signal->live);
810         if (group_dead) {                         971         if (group_dead) {
811 #ifdef CONFIG_POSIX_TIMERS                     << 
812                 hrtimer_cancel(&tsk->signal->r    972                 hrtimer_cancel(&tsk->signal->real_timer);
813                 exit_itimers(tsk->signal);        973                 exit_itimers(tsk->signal);
814 #endif                                         << 
815                 if (tsk->mm)                      974                 if (tsk->mm)
816                         setmax_mm_hiwater_rss(    975                         setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
817         }                                         976         }
818         acct_collect(code, group_dead);           977         acct_collect(code, group_dead);
819         if (group_dead)                           978         if (group_dead)
820                 tty_audit_exit();                 979                 tty_audit_exit();
821         audit_free(tsk);                       !! 980         if (unlikely(tsk->audit_context))
                                                   >> 981                 audit_free(tsk);
822                                                   982 
823         tsk->exit_code = code;                    983         tsk->exit_code = code;
824         taskstats_exit(tsk, group_dead);          984         taskstats_exit(tsk, group_dead);
825                                                   985 
826         exit_mm(tsk);                             986         exit_mm(tsk);
827                                                   987 
828         if (group_dead)                           988         if (group_dead)
829                 acct_process();                   989                 acct_process();
830         trace_sched_process_exit(tsk);            990         trace_sched_process_exit(tsk);
831                                                   991 
832         exit_sem(tsk);                            992         exit_sem(tsk);
833         exit_shm(tsk);                         << 
834         exit_files(tsk);                          993         exit_files(tsk);
835         exit_fs(tsk);                             994         exit_fs(tsk);
                                                   >> 995         check_stack_usage();
                                                   >> 996         exit_thread();
                                                   >> 997         cgroup_exit(tsk, 1);
                                                   >> 998 
836         if (group_dead)                           999         if (group_dead)
837                 disassociate_ctty(1);             1000                 disassociate_ctty(1);
838         exit_task_namespaces(tsk);             << 
839         exit_task_work(tsk);                   << 
840         exit_thread(tsk);                      << 
841                                                   1001 
842         /*                                     !! 1002         module_put(task_thread_info(tsk)->exec_domain->module);
843          * Flush inherited counters to the par << 
844          * gets woken up by child-exit notific << 
845          *                                     << 
846          * because of cgroup mode, must be cal << 
847          */                                    << 
848         perf_event_exit_task(tsk);             << 
849                                                   1003 
850         sched_autogroup_exit_task(tsk);        !! 1004         proc_exit_connector(tsk);
851         cgroup_exit(tsk);                      << 
852                                                   1005 
853         /*                                        1006         /*
854          * FIXME: do that only when needed, us    1007          * FIXME: do that only when needed, using sched_exit tracepoint
855          */                                       1008          */
856         flush_ptrace_hw_breakpoint(tsk);          1009         flush_ptrace_hw_breakpoint(tsk);
                                                   >> 1010         /*
                                                   >> 1011          * Flush inherited counters to the parent - before the parent
                                                   >> 1012          * gets woken up by child-exit notifications.
                                                   >> 1013          */
                                                   >> 1014         perf_event_exit_task(tsk);
857                                                   1015 
858         TASKS_RCU(preempt_disable());          << 
859         TASKS_RCU(tasks_rcu_i = __srcu_read_lo << 
860         TASKS_RCU(preempt_enable());           << 
861         exit_notify(tsk, group_dead);             1016         exit_notify(tsk, group_dead);
862         proc_exit_connector(tsk);              !! 1017 #ifdef CONFIG_NUMA
863         mpol_put_task_policy(tsk);             !! 1018         task_lock(tsk);
                                                   >> 1019         mpol_put(tsk->mempolicy);
                                                   >> 1020         tsk->mempolicy = NULL;
                                                   >> 1021         task_unlock(tsk);
                                                   >> 1022 #endif
864 #ifdef CONFIG_FUTEX                               1023 #ifdef CONFIG_FUTEX
865         if (unlikely(current->pi_state_cache))    1024         if (unlikely(current->pi_state_cache))
866                 kfree(current->pi_state_cache)    1025                 kfree(current->pi_state_cache);
867 #endif                                            1026 #endif
868         /*                                        1027         /*
869          * Make sure we are holding no locks:     1028          * Make sure we are holding no locks:
870          */                                       1029          */
871         debug_check_no_locks_held();           !! 1030         debug_check_no_locks_held(tsk);
872         /*                                        1031         /*
873          * We can do this unlocked here. The f    1032          * We can do this unlocked here. The futex code uses this flag
874          * just to verify whether the pi state    1033          * just to verify whether the pi state cleanup has been done
875          * or not. In the worst case it loops     1034          * or not. In the worst case it loops once more.
876          */                                       1035          */
877         tsk->flags |= PF_EXITPIDONE;              1036         tsk->flags |= PF_EXITPIDONE;
878                                                   1037 
879         if (tsk->io_context)                      1038         if (tsk->io_context)
880                 exit_io_context(tsk);             1039                 exit_io_context(tsk);
881                                                   1040 
882         if (tsk->splice_pipe)                     1041         if (tsk->splice_pipe)
883                 free_pipe_info(tsk->splice_pip !! 1042                 __free_pipe_info(tsk->splice_pipe);
884                                                << 
885         if (tsk->task_frag.page)               << 
886                 put_page(tsk->task_frag.page); << 
887                                                   1043 
888         validate_creds_for_do_exit(tsk);          1044         validate_creds_for_do_exit(tsk);
889                                                   1045 
890         check_stack_usage();                   << 
891         preempt_disable();                        1046         preempt_disable();
892         if (tsk->nr_dirtied)                   << 
893                 __this_cpu_add(dirty_throttle_ << 
894         exit_rcu();                               1047         exit_rcu();
895         TASKS_RCU(__srcu_read_unlock(&tasks_rc !! 1048         /* causes final put_task_struct in finish_task_switch(). */
896                                                !! 1049         tsk->state = TASK_DEAD;
897         do_task_dead();                        !! 1050         schedule();
                                                   >> 1051         BUG();
                                                   >> 1052         /* Avoid "noreturn function does return".  */
                                                   >> 1053         for (;;)
                                                   >> 1054                 cpu_relax();    /* For when BUG is null */
898 }                                                 1055 }
                                                   >> 1056 
899 EXPORT_SYMBOL_GPL(do_exit);                       1057 EXPORT_SYMBOL_GPL(do_exit);
900                                                   1058 
901 void complete_and_exit(struct completion *comp !! 1059 NORET_TYPE void complete_and_exit(struct completion *comp, long code)
902 {                                                 1060 {
903         if (comp)                                 1061         if (comp)
904                 complete(comp);                   1062                 complete(comp);
905                                                   1063 
906         do_exit(code);                            1064         do_exit(code);
907 }                                                 1065 }
                                                   >> 1066 
908 EXPORT_SYMBOL(complete_and_exit);                 1067 EXPORT_SYMBOL(complete_and_exit);
909                                                   1068 
910 SYSCALL_DEFINE1(exit, int, error_code)            1069 SYSCALL_DEFINE1(exit, int, error_code)
911 {                                                 1070 {
912         do_exit((error_code&0xff)<<8);            1071         do_exit((error_code&0xff)<<8);
913 }                                                 1072 }
914                                                   1073 
915 /*                                                1074 /*
916  * Take down every thread in the group.  This     1075  * Take down every thread in the group.  This is called by fatal signals
917  * as well as by sys_exit_group (below).          1076  * as well as by sys_exit_group (below).
918  */                                               1077  */
919 void                                           !! 1078 NORET_TYPE void
920 do_group_exit(int exit_code)                      1079 do_group_exit(int exit_code)
921 {                                                 1080 {
922         struct signal_struct *sig = current->s    1081         struct signal_struct *sig = current->signal;
923                                                   1082 
924         BUG_ON(exit_code & 0x80); /* core dump    1083         BUG_ON(exit_code & 0x80); /* core dumps don't get here */
925                                                   1084 
926         if (signal_group_exit(sig))               1085         if (signal_group_exit(sig))
927                 exit_code = sig->group_exit_co    1086                 exit_code = sig->group_exit_code;
928         else if (!thread_group_empty(current))    1087         else if (!thread_group_empty(current)) {
929                 struct sighand_struct *const s    1088                 struct sighand_struct *const sighand = current->sighand;
930                                                << 
931                 spin_lock_irq(&sighand->sigloc    1089                 spin_lock_irq(&sighand->siglock);
932                 if (signal_group_exit(sig))       1090                 if (signal_group_exit(sig))
933                         /* Another thread got     1091                         /* Another thread got here before we took the lock.  */
934                         exit_code = sig->group    1092                         exit_code = sig->group_exit_code;
935                 else {                            1093                 else {
936                         sig->group_exit_code =    1094                         sig->group_exit_code = exit_code;
937                         sig->flags = SIGNAL_GR    1095                         sig->flags = SIGNAL_GROUP_EXIT;
938                         zap_other_threads(curr    1096                         zap_other_threads(current);
939                 }                                 1097                 }
940                 spin_unlock_irq(&sighand->sigl    1098                 spin_unlock_irq(&sighand->siglock);
941         }                                         1099         }
942                                                   1100 
943         do_exit(exit_code);                       1101         do_exit(exit_code);
944         /* NOTREACHED */                          1102         /* NOTREACHED */
945 }                                                 1103 }
946                                                   1104 
947 /*                                                1105 /*
948  * this kills every thread in the thread group    1106  * this kills every thread in the thread group. Note that any externally
949  * wait4()-ing process will get the correct ex    1107  * wait4()-ing process will get the correct exit code - even if this
950  * thread is not the thread group leader.         1108  * thread is not the thread group leader.
951  */                                               1109  */
952 SYSCALL_DEFINE1(exit_group, int, error_code)      1110 SYSCALL_DEFINE1(exit_group, int, error_code)
953 {                                                 1111 {
954         do_group_exit((error_code & 0xff) << 8    1112         do_group_exit((error_code & 0xff) << 8);
955         /* NOTREACHED */                          1113         /* NOTREACHED */
956         return 0;                                 1114         return 0;
957 }                                                 1115 }
958                                                   1116 
959 struct wait_opts {                                1117 struct wait_opts {
960         enum pid_type           wo_type;          1118         enum pid_type           wo_type;
961         int                     wo_flags;         1119         int                     wo_flags;
962         struct pid              *wo_pid;          1120         struct pid              *wo_pid;
963                                                   1121 
964         struct siginfo __user   *wo_info;         1122         struct siginfo __user   *wo_info;
965         int __user              *wo_stat;         1123         int __user              *wo_stat;
966         struct rusage __user    *wo_rusage;       1124         struct rusage __user    *wo_rusage;
967                                                   1125 
968         wait_queue_t            child_wait;       1126         wait_queue_t            child_wait;
969         int                     notask_error;     1127         int                     notask_error;
970 };                                                1128 };
971                                                   1129 
972 static inline                                     1130 static inline
973 struct pid *task_pid_type(struct task_struct *    1131 struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
974 {                                                 1132 {
975         if (type != PIDTYPE_PID)                  1133         if (type != PIDTYPE_PID)
976                 task = task->group_leader;        1134                 task = task->group_leader;
977         return task->pids[type].pid;              1135         return task->pids[type].pid;
978 }                                                 1136 }
979                                                   1137 
980 static int eligible_pid(struct wait_opts *wo,     1138 static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
981 {                                                 1139 {
982         return  wo->wo_type == PIDTYPE_MAX ||     1140         return  wo->wo_type == PIDTYPE_MAX ||
983                 task_pid_type(p, wo->wo_type)     1141                 task_pid_type(p, wo->wo_type) == wo->wo_pid;
984 }                                                 1142 }
985                                                   1143 
986 static int                                     !! 1144 static int eligible_child(struct wait_opts *wo, struct task_struct *p)
987 eligible_child(struct wait_opts *wo, bool ptra << 
988 {                                                 1145 {
989         if (!eligible_pid(wo, p))                 1146         if (!eligible_pid(wo, p))
990                 return 0;                         1147                 return 0;
991                                                !! 1148         /* Wait for all children (clone and not) if __WALL is set;
992         /*                                     !! 1149          * otherwise, wait for clone children *only* if __WCLONE is
993          * Wait for all children (clone and no !! 1150          * set; otherwise, wait for non-clone children *only*.  (Note:
994          * if it is traced by us.              !! 1151          * A "clone" child here is one that reports to its parent
995          */                                    !! 1152          * using a signal other than SIGCHLD.) */
996         if (ptrace || (wo->wo_flags & __WALL)) !! 1153         if (((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
997                 return 1;                      !! 1154             && !(wo->wo_flags & __WALL))
998                                                << 
999         /*                                     << 
1000          * Otherwise, wait for clone children << 
1001          * otherwise, wait for non-clone chil << 
1002          *                                    << 
1003          * Note: a "clone" child here is one  << 
1004          * using a signal other than SIGCHLD, << 
1005          * we can only see if it is traced by << 
1006          */                                   << 
1007         if ((p->exit_signal != SIGCHLD) ^ !!( << 
1008                 return 0;                        1155                 return 0;
1009                                                  1156 
1010         return 1;                                1157         return 1;
1011 }                                                1158 }
1012                                                  1159 
1013 static int wait_noreap_copyout(struct wait_op    1160 static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
1014                                 pid_t pid, ui    1161                                 pid_t pid, uid_t uid, int why, int status)
1015 {                                                1162 {
1016         struct siginfo __user *infop;            1163         struct siginfo __user *infop;
1017         int retval = wo->wo_rusage               1164         int retval = wo->wo_rusage
1018                 ? getrusage(p, RUSAGE_BOTH, w    1165                 ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
1019                                                  1166 
1020         put_task_struct(p);                      1167         put_task_struct(p);
1021         infop = wo->wo_info;                     1168         infop = wo->wo_info;
1022         if (infop) {                             1169         if (infop) {
1023                 if (!retval)                     1170                 if (!retval)
1024                         retval = put_user(SIG    1171                         retval = put_user(SIGCHLD, &infop->si_signo);
1025                 if (!retval)                     1172                 if (!retval)
1026                         retval = put_user(0,     1173                         retval = put_user(0, &infop->si_errno);
1027                 if (!retval)                     1174                 if (!retval)
1028                         retval = put_user((sh    1175                         retval = put_user((short)why, &infop->si_code);
1029                 if (!retval)                     1176                 if (!retval)
1030                         retval = put_user(pid    1177                         retval = put_user(pid, &infop->si_pid);
1031                 if (!retval)                     1178                 if (!retval)
1032                         retval = put_user(uid    1179                         retval = put_user(uid, &infop->si_uid);
1033                 if (!retval)                     1180                 if (!retval)
1034                         retval = put_user(sta    1181                         retval = put_user(status, &infop->si_status);
1035         }                                        1182         }
1036         if (!retval)                             1183         if (!retval)
1037                 retval = pid;                    1184                 retval = pid;
1038         return retval;                           1185         return retval;
1039 }                                                1186 }
1040                                                  1187 
1041 /*                                               1188 /*
1042  * Handle sys_wait4 work for one task in stat    1189  * Handle sys_wait4 work for one task in state EXIT_ZOMBIE.  We hold
1043  * read_lock(&tasklist_lock) on entry.  If we    1190  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
1044  * the lock and this task is uninteresting.      1191  * the lock and this task is uninteresting.  If we return nonzero, we have
1045  * released the lock and the system call shou    1192  * released the lock and the system call should return.
1046  */                                              1193  */
1047 static int wait_task_zombie(struct wait_opts     1194 static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
1048 {                                                1195 {
1049         int state, retval, status;            !! 1196         unsigned long state;
                                                   >> 1197         int retval, status, traced;
1050         pid_t pid = task_pid_vnr(p);             1198         pid_t pid = task_pid_vnr(p);
1051         uid_t uid = from_kuid_munged(current_ !! 1199         uid_t uid = __task_cred(p)->uid;
1052         struct siginfo __user *infop;            1200         struct siginfo __user *infop;
1053                                                  1201 
1054         if (!likely(wo->wo_flags & WEXITED))     1202         if (!likely(wo->wo_flags & WEXITED))
1055                 return 0;                        1203                 return 0;
1056                                                  1204 
1057         if (unlikely(wo->wo_flags & WNOWAIT))    1205         if (unlikely(wo->wo_flags & WNOWAIT)) {
1058                 int exit_code = p->exit_code;    1206                 int exit_code = p->exit_code;
1059                 int why;                         1207                 int why;
1060                                                  1208 
1061                 get_task_struct(p);              1209                 get_task_struct(p);
1062                 read_unlock(&tasklist_lock);     1210                 read_unlock(&tasklist_lock);
1063                 sched_annotate_sleep();       << 
1064                                               << 
1065                 if ((exit_code & 0x7f) == 0)     1211                 if ((exit_code & 0x7f) == 0) {
1066                         why = CLD_EXITED;        1212                         why = CLD_EXITED;
1067                         status = exit_code >>    1213                         status = exit_code >> 8;
1068                 } else {                         1214                 } else {
1069                         why = (exit_code & 0x    1215                         why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
1070                         status = exit_code &     1216                         status = exit_code & 0x7f;
1071                 }                                1217                 }
1072                 return wait_noreap_copyout(wo    1218                 return wait_noreap_copyout(wo, p, pid, uid, why, status);
1073         }                                        1219         }
                                                   >> 1220 
1074         /*                                       1221         /*
1075          * Move the task's state to DEAD/TRAC !! 1222          * Try to move the task's state to DEAD
                                                   >> 1223          * only one thread is allowed to do this:
1076          */                                      1224          */
1077         state = (ptrace_reparented(p) && thre !! 1225         state = xchg(&p->exit_state, EXIT_DEAD);
1078                 EXIT_TRACE : EXIT_DEAD;       !! 1226         if (state != EXIT_ZOMBIE) {
1079         if (cmpxchg(&p->exit_state, EXIT_ZOMB !! 1227                 BUG_ON(state != EXIT_DEAD);
1080                 return 0;                        1228                 return 0;
1081         /*                                    !! 1229         }
1082          * We own this thread, nobody else ca << 
1083          */                                   << 
1084         read_unlock(&tasklist_lock);          << 
1085         sched_annotate_sleep();               << 
1086                                                  1230 
                                                   >> 1231         traced = ptrace_reparented(p);
1087         /*                                       1232         /*
1088          * Check thread_group_leader() to exc !! 1233          * It can be ptraced but not reparented, check
                                                   >> 1234          * !task_detached() to filter out sub-threads.
1089          */                                      1235          */
1090         if (state == EXIT_DEAD && thread_grou !! 1236         if (likely(!traced) && likely(!task_detached(p))) {
1091                 struct signal_struct *sig = p !! 1237                 struct signal_struct *psig;
1092                 struct signal_struct *psig =  !! 1238                 struct signal_struct *sig;
1093                 unsigned long maxrss;            1239                 unsigned long maxrss;
1094                 cputime_t tgutime, tgstime;      1240                 cputime_t tgutime, tgstime;
1095                                                  1241 
1096                 /*                               1242                 /*
1097                  * The resource counters for     1243                  * The resource counters for the group leader are in its
1098                  * own task_struct.  Those fo    1244                  * own task_struct.  Those for dead threads in the group
1099                  * are in its signal_struct,     1245                  * are in its signal_struct, as are those for the child
1100                  * processes it has previousl    1246                  * processes it has previously reaped.  All these
1101                  * accumulate in the parent's    1247                  * accumulate in the parent's signal_struct c* fields.
1102                  *                               1248                  *
1103                  * We don't bother to take a     1249                  * We don't bother to take a lock here to protect these
1104                  * p->signal fields because t !! 1250                  * p->signal fields, because they are only touched by
1105                  * and nobody can change them !! 1251                  * __exit_signal, which runs with tasklist_lock
1106                  *                            !! 1252                  * write-locked anyway, and so is excluded here.  We do
1107                  * psig->stats_lock also prot !! 1253                  * need to protect the access to parent->signal fields,
1108                  * which can reap other child !! 1254                  * as other threads in the parent group can be right
1109                  * we change k_getrusage()-li !! 1255                  * here reaping other children at the same time.
1110                  * we have to take ->siglock  << 
1111                  *                               1256                  *
1112                  * We use thread_group_cputim !! 1257                  * We use thread_group_times() to get times for the thread
1113                  * the thread group, which co !! 1258                  * group, which consolidates times for all threads in the
1114                  * in the group including the !! 1259                  * group including the group leader.
1115                  */                              1260                  */
1116                 thread_group_cputime_adjusted !! 1261                 thread_group_times(p, &tgutime, &tgstime);
1117                 spin_lock_irq(&current->sigha !! 1262                 spin_lock_irq(&p->real_parent->sighand->siglock);
1118                 write_seqlock(&psig->stats_lo !! 1263                 psig = p->real_parent->signal;
1119                 psig->cutime += tgutime + sig !! 1264                 sig = p->signal;
1120                 psig->cstime += tgstime + sig !! 1265                 psig->cutime =
1121                 psig->cgtime += task_gtime(p) !! 1266                         cputime_add(psig->cutime,
                                                   >> 1267                         cputime_add(tgutime,
                                                   >> 1268                                     sig->cutime));
                                                   >> 1269                 psig->cstime =
                                                   >> 1270                         cputime_add(psig->cstime,
                                                   >> 1271                         cputime_add(tgstime,
                                                   >> 1272                                     sig->cstime));
                                                   >> 1273                 psig->cgtime =
                                                   >> 1274                         cputime_add(psig->cgtime,
                                                   >> 1275                         cputime_add(p->gtime,
                                                   >> 1276                         cputime_add(sig->gtime,
                                                   >> 1277                                     sig->cgtime)));
1122                 psig->cmin_flt +=                1278                 psig->cmin_flt +=
1123                         p->min_flt + sig->min    1279                         p->min_flt + sig->min_flt + sig->cmin_flt;
1124                 psig->cmaj_flt +=                1280                 psig->cmaj_flt +=
1125                         p->maj_flt + sig->maj    1281                         p->maj_flt + sig->maj_flt + sig->cmaj_flt;
1126                 psig->cnvcsw +=                  1282                 psig->cnvcsw +=
1127                         p->nvcsw + sig->nvcsw    1283                         p->nvcsw + sig->nvcsw + sig->cnvcsw;
1128                 psig->cnivcsw +=                 1284                 psig->cnivcsw +=
1129                         p->nivcsw + sig->nivc    1285                         p->nivcsw + sig->nivcsw + sig->cnivcsw;
1130                 psig->cinblock +=                1286                 psig->cinblock +=
1131                         task_io_get_inblock(p    1287                         task_io_get_inblock(p) +
1132                         sig->inblock + sig->c    1288                         sig->inblock + sig->cinblock;
1133                 psig->coublock +=                1289                 psig->coublock +=
1134                         task_io_get_oublock(p    1290                         task_io_get_oublock(p) +
1135                         sig->oublock + sig->c    1291                         sig->oublock + sig->coublock;
1136                 maxrss = max(sig->maxrss, sig    1292                 maxrss = max(sig->maxrss, sig->cmaxrss);
1137                 if (psig->cmaxrss < maxrss)      1293                 if (psig->cmaxrss < maxrss)
1138                         psig->cmaxrss = maxrs    1294                         psig->cmaxrss = maxrss;
1139                 task_io_accounting_add(&psig-    1295                 task_io_accounting_add(&psig->ioac, &p->ioac);
1140                 task_io_accounting_add(&psig-    1296                 task_io_accounting_add(&psig->ioac, &sig->ioac);
1141                 write_sequnlock(&psig->stats_ !! 1297                 spin_unlock_irq(&p->real_parent->sighand->siglock);
1142                 spin_unlock_irq(&current->sig << 
1143         }                                        1298         }
1144                                                  1299 
                                                   >> 1300         /*
                                                   >> 1301          * Now we are sure this task is interesting, and no other
                                                   >> 1302          * thread can reap it because we set its state to EXIT_DEAD.
                                                   >> 1303          */
                                                   >> 1304         read_unlock(&tasklist_lock);
                                                   >> 1305 
1145         retval = wo->wo_rusage                   1306         retval = wo->wo_rusage
1146                 ? getrusage(p, RUSAGE_BOTH, w    1307                 ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
1147         status = (p->signal->flags & SIGNAL_G    1308         status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1148                 ? p->signal->group_exit_code     1309                 ? p->signal->group_exit_code : p->exit_code;
1149         if (!retval && wo->wo_stat)              1310         if (!retval && wo->wo_stat)
1150                 retval = put_user(status, wo-    1311                 retval = put_user(status, wo->wo_stat);
1151                                                  1312 
1152         infop = wo->wo_info;                     1313         infop = wo->wo_info;
1153         if (!retval && infop)                    1314         if (!retval && infop)
1154                 retval = put_user(SIGCHLD, &i    1315                 retval = put_user(SIGCHLD, &infop->si_signo);
1155         if (!retval && infop)                    1316         if (!retval && infop)
1156                 retval = put_user(0, &infop->    1317                 retval = put_user(0, &infop->si_errno);
1157         if (!retval && infop) {                  1318         if (!retval && infop) {
1158                 int why;                         1319                 int why;
1159                                                  1320 
1160                 if ((status & 0x7f) == 0) {      1321                 if ((status & 0x7f) == 0) {
1161                         why = CLD_EXITED;        1322                         why = CLD_EXITED;
1162                         status >>= 8;            1323                         status >>= 8;
1163                 } else {                         1324                 } else {
1164                         why = (status & 0x80)    1325                         why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
1165                         status &= 0x7f;          1326                         status &= 0x7f;
1166                 }                                1327                 }
1167                 retval = put_user((short)why,    1328                 retval = put_user((short)why, &infop->si_code);
1168                 if (!retval)                     1329                 if (!retval)
1169                         retval = put_user(sta    1330                         retval = put_user(status, &infop->si_status);
1170         }                                        1331         }
1171         if (!retval && infop)                    1332         if (!retval && infop)
1172                 retval = put_user(pid, &infop    1333                 retval = put_user(pid, &infop->si_pid);
1173         if (!retval && infop)                    1334         if (!retval && infop)
1174                 retval = put_user(uid, &infop    1335                 retval = put_user(uid, &infop->si_uid);
1175         if (!retval)                             1336         if (!retval)
1176                 retval = pid;                    1337                 retval = pid;
1177                                                  1338 
1178         if (state == EXIT_TRACE) {            !! 1339         if (traced) {
1179                 write_lock_irq(&tasklist_lock    1340                 write_lock_irq(&tasklist_lock);
1180                 /* We dropped tasklist, ptrac    1341                 /* We dropped tasklist, ptracer could die and untrace */
1181                 ptrace_unlink(p);                1342                 ptrace_unlink(p);
1182                                               !! 1343                 /*
1183                 /* If parent wants a zombie,  !! 1344                  * If this is not a detached task, notify the parent.
1184                 state = EXIT_ZOMBIE;          !! 1345                  * If it's still not detached after that, don't release
1185                 if (do_notify_parent(p, p->ex !! 1346                  * it now.
1186                         state = EXIT_DEAD;    !! 1347                  */
1187                 p->exit_state = state;        !! 1348                 if (!task_detached(p)) {
                                                   >> 1349                         do_notify_parent(p, p->exit_signal);
                                                   >> 1350                         if (!task_detached(p)) {
                                                   >> 1351                                 p->exit_state = EXIT_ZOMBIE;
                                                   >> 1352                                 p = NULL;
                                                   >> 1353                         }
                                                   >> 1354                 }
1188                 write_unlock_irq(&tasklist_lo    1355                 write_unlock_irq(&tasklist_lock);
1189         }                                        1356         }
1190         if (state == EXIT_DEAD)               !! 1357         if (p != NULL)
1191                 release_task(p);                 1358                 release_task(p);
1192                                                  1359 
1193         return retval;                           1360         return retval;
1194 }                                                1361 }
1195                                                  1362 
1196 static int *task_stopped_code(struct task_str    1363 static int *task_stopped_code(struct task_struct *p, bool ptrace)
1197 {                                                1364 {
1198         if (ptrace) {                            1365         if (ptrace) {
1199                 if (task_is_traced(p) && !(p- !! 1366                 if (task_is_stopped_or_traced(p))
1200                         return &p->exit_code;    1367                         return &p->exit_code;
1201         } else {                                 1368         } else {
1202                 if (p->signal->flags & SIGNAL    1369                 if (p->signal->flags & SIGNAL_STOP_STOPPED)
1203                         return &p->signal->gr    1370                         return &p->signal->group_exit_code;
1204         }                                        1371         }
1205         return NULL;                             1372         return NULL;
1206 }                                                1373 }
1207                                                  1374 
1208 /**                                           !! 1375 /*
1209  * wait_task_stopped - Wait for %TASK_STOPPED !! 1376  * Handle sys_wait4 work for one task in state TASK_STOPPED.  We hold
1210  * @wo: wait options                          !! 1377  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
1211  * @ptrace: is the wait for ptrace            !! 1378  * the lock and this task is uninteresting.  If we return nonzero, we have
1212  * @p: task to wait for                       !! 1379  * released the lock and the system call should return.
1213  *                                            << 
1214  * Handle sys_wait4() work for %p in state %T << 
1215  *                                            << 
1216  * CONTEXT:                                   << 
1217  * read_lock(&tasklist_lock), which is releas << 
1218  * non-zero.  Also, grabs and releases @p->si << 
1219  *                                            << 
1220  * RETURNS:                                   << 
1221  * 0 if wait condition didn't exist and searc << 
1222  * should continue.  Non-zero return, -errno  << 
1223  * success, implies that tasklist_lock is rel << 
1224  * search should terminate.                   << 
1225  */                                              1380  */
1226 static int wait_task_stopped(struct wait_opts    1381 static int wait_task_stopped(struct wait_opts *wo,
1227                                 int ptrace, s    1382                                 int ptrace, struct task_struct *p)
1228 {                                                1383 {
1229         struct siginfo __user *infop;            1384         struct siginfo __user *infop;
1230         int retval, exit_code, *p_code, why;     1385         int retval, exit_code, *p_code, why;
1231         uid_t uid = 0; /* unneeded, required     1386         uid_t uid = 0; /* unneeded, required by compiler */
1232         pid_t pid;                               1387         pid_t pid;
1233                                                  1388 
1234         /*                                       1389         /*
1235          * Traditionally we see ptrace'd stop    1390          * Traditionally we see ptrace'd stopped tasks regardless of options.
1236          */                                      1391          */
1237         if (!ptrace && !(wo->wo_flags & WUNTR    1392         if (!ptrace && !(wo->wo_flags & WUNTRACED))
1238                 return 0;                        1393                 return 0;
1239                                                  1394 
1240         if (!task_stopped_code(p, ptrace))    << 
1241                 return 0;                     << 
1242                                               << 
1243         exit_code = 0;                           1395         exit_code = 0;
1244         spin_lock_irq(&p->sighand->siglock);     1396         spin_lock_irq(&p->sighand->siglock);
1245                                                  1397 
1246         p_code = task_stopped_code(p, ptrace)    1398         p_code = task_stopped_code(p, ptrace);
1247         if (unlikely(!p_code))                   1399         if (unlikely(!p_code))
1248                 goto unlock_sig;                 1400                 goto unlock_sig;
1249                                                  1401 
1250         exit_code = *p_code;                     1402         exit_code = *p_code;
1251         if (!exit_code)                          1403         if (!exit_code)
1252                 goto unlock_sig;                 1404                 goto unlock_sig;
1253                                                  1405 
1254         if (!unlikely(wo->wo_flags & WNOWAIT)    1406         if (!unlikely(wo->wo_flags & WNOWAIT))
1255                 *p_code = 0;                     1407                 *p_code = 0;
1256                                                  1408 
1257         uid = from_kuid_munged(current_user_n !! 1409         uid = task_uid(p);
1258 unlock_sig:                                      1410 unlock_sig:
1259         spin_unlock_irq(&p->sighand->siglock)    1411         spin_unlock_irq(&p->sighand->siglock);
1260         if (!exit_code)                          1412         if (!exit_code)
1261                 return 0;                        1413                 return 0;
1262                                                  1414 
1263         /*                                       1415         /*
1264          * Now we are pretty sure this task i    1416          * Now we are pretty sure this task is interesting.
1265          * Make sure it doesn't get reaped ou    1417          * Make sure it doesn't get reaped out from under us while we
1266          * give up the lock and then examine     1418          * give up the lock and then examine it below.  We don't want to
1267          * keep holding onto the tasklist_loc    1419          * keep holding onto the tasklist_lock while we call getrusage and
1268          * possibly take page faults for user    1420          * possibly take page faults for user memory.
1269          */                                      1421          */
1270         get_task_struct(p);                      1422         get_task_struct(p);
1271         pid = task_pid_vnr(p);                   1423         pid = task_pid_vnr(p);
1272         why = ptrace ? CLD_TRAPPED : CLD_STOP    1424         why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
1273         read_unlock(&tasklist_lock);             1425         read_unlock(&tasklist_lock);
1274         sched_annotate_sleep();               << 
1275                                                  1426 
1276         if (unlikely(wo->wo_flags & WNOWAIT))    1427         if (unlikely(wo->wo_flags & WNOWAIT))
1277                 return wait_noreap_copyout(wo    1428                 return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);
1278                                                  1429 
1279         retval = wo->wo_rusage                   1430         retval = wo->wo_rusage
1280                 ? getrusage(p, RUSAGE_BOTH, w    1431                 ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
1281         if (!retval && wo->wo_stat)              1432         if (!retval && wo->wo_stat)
1282                 retval = put_user((exit_code     1433                 retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
1283                                                  1434 
1284         infop = wo->wo_info;                     1435         infop = wo->wo_info;
1285         if (!retval && infop)                    1436         if (!retval && infop)
1286                 retval = put_user(SIGCHLD, &i    1437                 retval = put_user(SIGCHLD, &infop->si_signo);
1287         if (!retval && infop)                    1438         if (!retval && infop)
1288                 retval = put_user(0, &infop->    1439                 retval = put_user(0, &infop->si_errno);
1289         if (!retval && infop)                    1440         if (!retval && infop)
1290                 retval = put_user((short)why,    1441                 retval = put_user((short)why, &infop->si_code);
1291         if (!retval && infop)                    1442         if (!retval && infop)
1292                 retval = put_user(exit_code,     1443                 retval = put_user(exit_code, &infop->si_status);
1293         if (!retval && infop)                    1444         if (!retval && infop)
1294                 retval = put_user(pid, &infop    1445                 retval = put_user(pid, &infop->si_pid);
1295         if (!retval && infop)                    1446         if (!retval && infop)
1296                 retval = put_user(uid, &infop    1447                 retval = put_user(uid, &infop->si_uid);
1297         if (!retval)                             1448         if (!retval)
1298                 retval = pid;                    1449                 retval = pid;
1299         put_task_struct(p);                      1450         put_task_struct(p);
1300                                                  1451 
1301         BUG_ON(!retval);                         1452         BUG_ON(!retval);
1302         return retval;                           1453         return retval;
1303 }                                                1454 }
1304                                                  1455 
1305 /*                                               1456 /*
1306  * Handle do_wait work for one task in a live    1457  * Handle do_wait work for one task in a live, non-stopped state.
1307  * read_lock(&tasklist_lock) on entry.  If we    1458  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
1308  * the lock and this task is uninteresting.      1459  * the lock and this task is uninteresting.  If we return nonzero, we have
1309  * released the lock and the system call shou    1460  * released the lock and the system call should return.
1310  */                                              1461  */
1311 static int wait_task_continued(struct wait_op    1462 static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
1312 {                                                1463 {
1313         int retval;                              1464         int retval;
1314         pid_t pid;                               1465         pid_t pid;
1315         uid_t uid;                               1466         uid_t uid;
1316                                                  1467 
1317         if (!unlikely(wo->wo_flags & WCONTINU    1468         if (!unlikely(wo->wo_flags & WCONTINUED))
1318                 return 0;                        1469                 return 0;
1319                                                  1470 
1320         if (!(p->signal->flags & SIGNAL_STOP_    1471         if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
1321                 return 0;                        1472                 return 0;
1322                                                  1473 
1323         spin_lock_irq(&p->sighand->siglock);     1474         spin_lock_irq(&p->sighand->siglock);
1324         /* Re-check with the lock held.  */      1475         /* Re-check with the lock held.  */
1325         if (!(p->signal->flags & SIGNAL_STOP_    1476         if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
1326                 spin_unlock_irq(&p->sighand->    1477                 spin_unlock_irq(&p->sighand->siglock);
1327                 return 0;                        1478                 return 0;
1328         }                                        1479         }
1329         if (!unlikely(wo->wo_flags & WNOWAIT)    1480         if (!unlikely(wo->wo_flags & WNOWAIT))
1330                 p->signal->flags &= ~SIGNAL_S    1481                 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
1331         uid = from_kuid_munged(current_user_n !! 1482         uid = task_uid(p);
1332         spin_unlock_irq(&p->sighand->siglock)    1483         spin_unlock_irq(&p->sighand->siglock);
1333                                                  1484 
1334         pid = task_pid_vnr(p);                   1485         pid = task_pid_vnr(p);
1335         get_task_struct(p);                      1486         get_task_struct(p);
1336         read_unlock(&tasklist_lock);             1487         read_unlock(&tasklist_lock);
1337         sched_annotate_sleep();               << 
1338                                                  1488 
1339         if (!wo->wo_info) {                      1489         if (!wo->wo_info) {
1340                 retval = wo->wo_rusage           1490                 retval = wo->wo_rusage
1341                         ? getrusage(p, RUSAGE    1491                         ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
1342                 put_task_struct(p);              1492                 put_task_struct(p);
1343                 if (!retval && wo->wo_stat)      1493                 if (!retval && wo->wo_stat)
1344                         retval = put_user(0xf    1494                         retval = put_user(0xffff, wo->wo_stat);
1345                 if (!retval)                     1495                 if (!retval)
1346                         retval = pid;            1496                         retval = pid;
1347         } else {                                 1497         } else {
1348                 retval = wait_noreap_copyout(    1498                 retval = wait_noreap_copyout(wo, p, pid, uid,
1349                                                  1499                                              CLD_CONTINUED, SIGCONT);
1350                 BUG_ON(retval == 0);             1500                 BUG_ON(retval == 0);
1351         }                                        1501         }
1352                                                  1502 
1353         return retval;                           1503         return retval;
1354 }                                                1504 }
1355                                                  1505 
1356 /*                                               1506 /*
1357  * Consider @p for a wait by @parent.            1507  * Consider @p for a wait by @parent.
1358  *                                               1508  *
1359  * -ECHILD should be in ->notask_error before    1509  * -ECHILD should be in ->notask_error before the first call.
1360  * Returns nonzero for a final return, when w    1510  * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1361  * Returns zero if the search for a child sho    1511  * Returns zero if the search for a child should continue;
1362  * then ->notask_error is 0 if @p is an eligi    1512  * then ->notask_error is 0 if @p is an eligible child,
1363  * or another error from security_task_wait()    1513  * or another error from security_task_wait(), or still -ECHILD.
1364  */                                              1514  */
1365 static int wait_consider_task(struct wait_opt    1515 static int wait_consider_task(struct wait_opts *wo, int ptrace,
1366                                 struct task_s    1516                                 struct task_struct *p)
1367 {                                                1517 {
1368         /*                                    !! 1518         int ret = eligible_child(wo, p);
1369          * We can race with wait_task_zombie( << 
1370          * Ensure that EXIT_ZOMBIE -> EXIT_DE << 
1371          * can't confuse the checks below.    << 
1372          */                                   << 
1373         int exit_state = ACCESS_ONCE(p->exit_ << 
1374         int ret;                              << 
1375                                               << 
1376         if (unlikely(exit_state == EXIT_DEAD) << 
1377                 return 0;                     << 
1378                                               << 
1379         ret = eligible_child(wo, ptrace, p);  << 
1380         if (!ret)                                1519         if (!ret)
1381                 return ret;                      1520                 return ret;
1382                                                  1521 
1383         ret = security_task_wait(p);             1522         ret = security_task_wait(p);
1384         if (unlikely(ret < 0)) {                 1523         if (unlikely(ret < 0)) {
1385                 /*                               1524                 /*
1386                  * If we have not yet seen an    1525                  * If we have not yet seen any eligible child,
1387                  * then let this error code r    1526                  * then let this error code replace -ECHILD.
1388                  * A permission error will gi    1527                  * A permission error will give the user a clue
1389                  * to look for security polic    1528                  * to look for security policy problems, rather
1390                  * than for mysterious wait b    1529                  * than for mysterious wait bugs.
1391                  */                              1530                  */
1392                 if (wo->notask_error)            1531                 if (wo->notask_error)
1393                         wo->notask_error = re    1532                         wo->notask_error = ret;
1394                 return 0;                        1533                 return 0;
1395         }                                        1534         }
1396                                                  1535 
1397         if (unlikely(exit_state == EXIT_TRACE !! 1536         if (likely(!ptrace) && unlikely(task_ptrace(p))) {
1398                 /*                               1537                 /*
1399                  * ptrace == 0 means we are t !! 1538                  * This child is hidden by ptrace.
1400                  * we should clear notask_err !! 1539                  * We aren't allowed to see it now, but eventually we will.
1401                  */                              1540                  */
1402                 if (likely(!ptrace))          !! 1541                 wo->notask_error = 0;
1403                         wo->notask_error = 0; << 
1404                 return 0;                        1542                 return 0;
1405         }                                        1543         }
1406                                                  1544 
1407         if (likely(!ptrace) && unlikely(p->pt !! 1545         if (p->exit_state == EXIT_DEAD)
1408                 /*                            !! 1546                 return 0;
1409                  * If it is traced by its rea << 
1410                  * the caller is ptrace_do_wa << 
1411                  * is zombie.                 << 
1412                  *                            << 
1413                  * This also hides group stop << 
1414                  * a single stop can be repor << 
1415                  * If a ptracer wants to dist << 
1416                  * own children it should cre << 
1417                  * the role of real parent.   << 
1418                  */                           << 
1419                 if (!ptrace_reparented(p))    << 
1420                         ptrace = 1;           << 
1421         }                                     << 
1422                                               << 
1423         /* slay zombie? */                    << 
1424         if (exit_state == EXIT_ZOMBIE) {      << 
1425                 /* we don't reap group leader << 
1426                 if (!delay_group_leader(p)) { << 
1427                         /*                    << 
1428                          * A zombie ptracee i << 
1429                          * Notification and r << 
1430                          * real parent when t << 
1431                          */                   << 
1432                         if (unlikely(ptrace)  << 
1433                                 return wait_t << 
1434                 }                             << 
1435                                               << 
1436                 /*                            << 
1437                  * Allow access to stopped/co << 
1438                  * falling through.  Clearing << 
1439                  *                            << 
1440                  * When !@ptrace:             << 
1441                  *                            << 
1442                  * If WEXITED is set, notask_ << 
1443                  * cleared.  If not, subset o << 
1444                  * so, if there are live subt << 
1445                  * wait for.  If all subthrea << 
1446                  * to clear - this function w << 
1447                  * amount time once all the s << 
1448                  * will then return without c << 
1449                  *                            << 
1450                  * When @ptrace:              << 
1451                  *                            << 
1452                  * Stopped state is per-task  << 
1453                  * target task dies.  Only co << 
1454                  * Clear notask_error if WCON << 
1455                  */                           << 
1456                 if (likely(!ptrace) || (wo->w << 
1457                         wo->notask_error = 0; << 
1458         } else {                              << 
1459                 /*                            << 
1460                  * @p is alive and it's gonna << 
1461                  * there always is something  << 
1462                  */                           << 
1463                 wo->notask_error = 0;         << 
1464         }                                     << 
1465                                                  1547 
1466         /*                                       1548         /*
1467          * Wait for stopped.  Depending on @p !! 1549          * We don't reap group leaders with subthreads.
1468          * is used and the two don't interact << 
1469          */                                      1550          */
1470         ret = wait_task_stopped(wo, ptrace, p !! 1551         if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p))
1471         if (ret)                              !! 1552                 return wait_task_zombie(wo, p);
1472                 return ret;                   << 
1473                                                  1553 
1474         /*                                       1554         /*
1475          * Wait for continued.  There's only  !! 1555          * It's stopped or running now, so it might
1476          * ptracer can consume it which can c !! 1556          * later continue, exit, or stop again.
1477          * use WCONTINUED from ptracer.  You  << 
1478          */                                      1557          */
                                                   >> 1558         wo->notask_error = 0;
                                                   >> 1559 
                                                   >> 1560         if (task_stopped_code(p, ptrace))
                                                   >> 1561                 return wait_task_stopped(wo, ptrace, p);
                                                   >> 1562 
1479         return wait_task_continued(wo, p);       1563         return wait_task_continued(wo, p);
1480 }                                                1564 }
1481                                                  1565 
1482 /*                                               1566 /*
1483  * Do the work of do_wait() for one thread in    1567  * Do the work of do_wait() for one thread in the group, @tsk.
1484  *                                               1568  *
1485  * -ECHILD should be in ->notask_error before    1569  * -ECHILD should be in ->notask_error before the first call.
1486  * Returns nonzero for a final return, when w    1570  * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1487  * Returns zero if the search for a child sho    1571  * Returns zero if the search for a child should continue; then
1488  * ->notask_error is 0 if there were any elig    1572  * ->notask_error is 0 if there were any eligible children,
1489  * or another error from security_task_wait()    1573  * or another error from security_task_wait(), or still -ECHILD.
1490  */                                              1574  */
1491 static int do_wait_thread(struct wait_opts *w    1575 static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
1492 {                                                1576 {
1493         struct task_struct *p;                   1577         struct task_struct *p;
1494                                                  1578 
1495         list_for_each_entry(p, &tsk->children    1579         list_for_each_entry(p, &tsk->children, sibling) {
1496                 int ret = wait_consider_task(    1580                 int ret = wait_consider_task(wo, 0, p);
1497                                               << 
1498                 if (ret)                         1581                 if (ret)
1499                         return ret;              1582                         return ret;
1500         }                                        1583         }
1501                                                  1584 
1502         return 0;                                1585         return 0;
1503 }                                                1586 }
1504                                                  1587 
1505 static int ptrace_do_wait(struct wait_opts *w    1588 static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
1506 {                                                1589 {
1507         struct task_struct *p;                   1590         struct task_struct *p;
1508                                                  1591 
1509         list_for_each_entry(p, &tsk->ptraced,    1592         list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
1510                 int ret = wait_consider_task(    1593                 int ret = wait_consider_task(wo, 1, p);
1511                                               << 
1512                 if (ret)                         1594                 if (ret)
1513                         return ret;              1595                         return ret;
1514         }                                        1596         }
1515                                                  1597 
1516         return 0;                                1598         return 0;
1517 }                                                1599 }
1518                                                  1600 
1519 static int child_wait_callback(wait_queue_t *    1601 static int child_wait_callback(wait_queue_t *wait, unsigned mode,
1520                                 int sync, voi    1602                                 int sync, void *key)
1521 {                                                1603 {
1522         struct wait_opts *wo = container_of(w    1604         struct wait_opts *wo = container_of(wait, struct wait_opts,
1523                                                  1605                                                 child_wait);
1524         struct task_struct *p = key;             1606         struct task_struct *p = key;
1525                                                  1607 
1526         if (!eligible_pid(wo, p))                1608         if (!eligible_pid(wo, p))
1527                 return 0;                        1609                 return 0;
1528                                                  1610 
1529         if ((wo->wo_flags & __WNOTHREAD) && w    1611         if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
1530                 return 0;                        1612                 return 0;
1531                                                  1613 
1532         return default_wake_function(wait, mo    1614         return default_wake_function(wait, mode, sync, key);
1533 }                                                1615 }
1534                                                  1616 
1535 void __wake_up_parent(struct task_struct *p,     1617 void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
1536 {                                                1618 {
1537         __wake_up_sync_key(&parent->signal->w    1619         __wake_up_sync_key(&parent->signal->wait_chldexit,
1538                                 TASK_INTERRUP    1620                                 TASK_INTERRUPTIBLE, 1, p);
1539 }                                                1621 }
1540                                                  1622 
1541 static long do_wait(struct wait_opts *wo)        1623 static long do_wait(struct wait_opts *wo)
1542 {                                                1624 {
1543         struct task_struct *tsk;                 1625         struct task_struct *tsk;
1544         int retval;                              1626         int retval;
1545                                                  1627 
1546         trace_sched_process_wait(wo->wo_pid);    1628         trace_sched_process_wait(wo->wo_pid);
1547                                                  1629 
1548         init_waitqueue_func_entry(&wo->child_    1630         init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
1549         wo->child_wait.private = current;        1631         wo->child_wait.private = current;
1550         add_wait_queue(&current->signal->wait    1632         add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
1551 repeat:                                          1633 repeat:
1552         /*                                       1634         /*
1553          * If there is nothing that can match !! 1635          * If there is nothing that can match our critiera just get out.
1554          * We will clear ->notask_error to ze    1636          * We will clear ->notask_error to zero if we see any child that
1555          * might later match our criteria, ev    1637          * might later match our criteria, even if we are not able to reap
1556          * it yet.                               1638          * it yet.
1557          */                                      1639          */
1558         wo->notask_error = -ECHILD;              1640         wo->notask_error = -ECHILD;
1559         if ((wo->wo_type < PIDTYPE_MAX) &&       1641         if ((wo->wo_type < PIDTYPE_MAX) &&
1560            (!wo->wo_pid || hlist_empty(&wo->w    1642            (!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type])))
1561                 goto notask;                     1643                 goto notask;
1562                                                  1644 
1563         set_current_state(TASK_INTERRUPTIBLE)    1645         set_current_state(TASK_INTERRUPTIBLE);
1564         read_lock(&tasklist_lock);               1646         read_lock(&tasklist_lock);
1565         tsk = current;                           1647         tsk = current;
1566         do {                                     1648         do {
1567                 retval = do_wait_thread(wo, t    1649                 retval = do_wait_thread(wo, tsk);
1568                 if (retval)                      1650                 if (retval)
1569                         goto end;                1651                         goto end;
1570                                                  1652 
1571                 retval = ptrace_do_wait(wo, t    1653                 retval = ptrace_do_wait(wo, tsk);
1572                 if (retval)                      1654                 if (retval)
1573                         goto end;                1655                         goto end;
1574                                                  1656 
1575                 if (wo->wo_flags & __WNOTHREA    1657                 if (wo->wo_flags & __WNOTHREAD)
1576                         break;                   1658                         break;
1577         } while_each_thread(current, tsk);       1659         } while_each_thread(current, tsk);
1578         read_unlock(&tasklist_lock);             1660         read_unlock(&tasklist_lock);
1579                                                  1661 
1580 notask:                                          1662 notask:
1581         retval = wo->notask_error;               1663         retval = wo->notask_error;
1582         if (!retval && !(wo->wo_flags & WNOHA    1664         if (!retval && !(wo->wo_flags & WNOHANG)) {
1583                 retval = -ERESTARTSYS;           1665                 retval = -ERESTARTSYS;
1584                 if (!signal_pending(current))    1666                 if (!signal_pending(current)) {
1585                         schedule();              1667                         schedule();
1586                         goto repeat;             1668                         goto repeat;
1587                 }                                1669                 }
1588         }                                        1670         }
1589 end:                                             1671 end:
1590         __set_current_state(TASK_RUNNING);       1672         __set_current_state(TASK_RUNNING);
1591         remove_wait_queue(&current->signal->w    1673         remove_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
1592         return retval;                           1674         return retval;
1593 }                                                1675 }
1594                                                  1676 
1595 SYSCALL_DEFINE5(waitid, int, which, pid_t, up    1677 SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
1596                 infop, int, options, struct r    1678                 infop, int, options, struct rusage __user *, ru)
1597 {                                                1679 {
1598         struct wait_opts wo;                     1680         struct wait_opts wo;
1599         struct pid *pid = NULL;                  1681         struct pid *pid = NULL;
1600         enum pid_type type;                      1682         enum pid_type type;
1601         long ret;                                1683         long ret;
1602                                                  1684 
1603         if (options & ~(WNOHANG|WNOWAIT|WEXIT !! 1685         if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
1604                         __WNOTHREAD|__WCLONE| << 
1605                 return -EINVAL;                  1686                 return -EINVAL;
1606         if (!(options & (WEXITED|WSTOPPED|WCO    1687         if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
1607                 return -EINVAL;                  1688                 return -EINVAL;
1608                                                  1689 
1609         switch (which) {                         1690         switch (which) {
1610         case P_ALL:                              1691         case P_ALL:
1611                 type = PIDTYPE_MAX;              1692                 type = PIDTYPE_MAX;
1612                 break;                           1693                 break;
1613         case P_PID:                              1694         case P_PID:
1614                 type = PIDTYPE_PID;              1695                 type = PIDTYPE_PID;
1615                 if (upid <= 0)                   1696                 if (upid <= 0)
1616                         return -EINVAL;          1697                         return -EINVAL;
1617                 break;                           1698                 break;
1618         case P_PGID:                             1699         case P_PGID:
1619                 type = PIDTYPE_PGID;             1700                 type = PIDTYPE_PGID;
1620                 if (upid <= 0)                   1701                 if (upid <= 0)
1621                         return -EINVAL;          1702                         return -EINVAL;
1622                 break;                           1703                 break;
1623         default:                                 1704         default:
1624                 return -EINVAL;                  1705                 return -EINVAL;
1625         }                                        1706         }
1626                                                  1707 
1627         if (type < PIDTYPE_MAX)                  1708         if (type < PIDTYPE_MAX)
1628                 pid = find_get_pid(upid);        1709                 pid = find_get_pid(upid);
1629                                                  1710 
1630         wo.wo_type      = type;                  1711         wo.wo_type      = type;
1631         wo.wo_pid       = pid;                   1712         wo.wo_pid       = pid;
1632         wo.wo_flags     = options;               1713         wo.wo_flags     = options;
1633         wo.wo_info      = infop;                 1714         wo.wo_info      = infop;
1634         wo.wo_stat      = NULL;                  1715         wo.wo_stat      = NULL;
1635         wo.wo_rusage    = ru;                    1716         wo.wo_rusage    = ru;
1636         ret = do_wait(&wo);                      1717         ret = do_wait(&wo);
1637                                                  1718 
1638         if (ret > 0) {                           1719         if (ret > 0) {
1639                 ret = 0;                         1720                 ret = 0;
1640         } else if (infop) {                      1721         } else if (infop) {
1641                 /*                               1722                 /*
1642                  * For a WNOHANG return, clea    1723                  * For a WNOHANG return, clear out all the fields
1643                  * we would set so the user c    1724                  * we would set so the user can easily tell the
1644                  * difference.                   1725                  * difference.
1645                  */                              1726                  */
1646                 if (!ret)                        1727                 if (!ret)
1647                         ret = put_user(0, &in    1728                         ret = put_user(0, &infop->si_signo);
1648                 if (!ret)                        1729                 if (!ret)
1649                         ret = put_user(0, &in    1730                         ret = put_user(0, &infop->si_errno);
1650                 if (!ret)                        1731                 if (!ret)
1651                         ret = put_user(0, &in    1732                         ret = put_user(0, &infop->si_code);
1652                 if (!ret)                        1733                 if (!ret)
1653                         ret = put_user(0, &in    1734                         ret = put_user(0, &infop->si_pid);
1654                 if (!ret)                        1735                 if (!ret)
1655                         ret = put_user(0, &in    1736                         ret = put_user(0, &infop->si_uid);
1656                 if (!ret)                        1737                 if (!ret)
1657                         ret = put_user(0, &in    1738                         ret = put_user(0, &infop->si_status);
1658         }                                        1739         }
1659                                                  1740 
1660         put_pid(pid);                            1741         put_pid(pid);
                                                   >> 1742 
                                                   >> 1743         /* avoid REGPARM breakage on x86: */
                                                   >> 1744         asmlinkage_protect(5, ret, which, upid, infop, options, ru);
1661         return ret;                              1745         return ret;
1662 }                                                1746 }
1663                                                  1747 
1664 SYSCALL_DEFINE4(wait4, pid_t, upid, int __use    1748 SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
1665                 int, options, struct rusage _    1749                 int, options, struct rusage __user *, ru)
1666 {                                                1750 {
1667         struct wait_opts wo;                     1751         struct wait_opts wo;
1668         struct pid *pid = NULL;                  1752         struct pid *pid = NULL;
1669         enum pid_type type;                      1753         enum pid_type type;
1670         long ret;                                1754         long ret;
1671                                                  1755 
1672         if (options & ~(WNOHANG|WUNTRACED|WCO    1756         if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
1673                         __WNOTHREAD|__WCLONE|    1757                         __WNOTHREAD|__WCLONE|__WALL))
1674                 return -EINVAL;                  1758                 return -EINVAL;
1675                                                  1759 
1676         if (upid == -1)                          1760         if (upid == -1)
1677                 type = PIDTYPE_MAX;              1761                 type = PIDTYPE_MAX;
1678         else if (upid < 0) {                     1762         else if (upid < 0) {
1679                 type = PIDTYPE_PGID;             1763                 type = PIDTYPE_PGID;
1680                 pid = find_get_pid(-upid);       1764                 pid = find_get_pid(-upid);
1681         } else if (upid == 0) {                  1765         } else if (upid == 0) {
1682                 type = PIDTYPE_PGID;             1766                 type = PIDTYPE_PGID;
1683                 pid = get_task_pid(current, P    1767                 pid = get_task_pid(current, PIDTYPE_PGID);
1684         } else /* upid > 0 */ {                  1768         } else /* upid > 0 */ {
1685                 type = PIDTYPE_PID;              1769                 type = PIDTYPE_PID;
1686                 pid = find_get_pid(upid);        1770                 pid = find_get_pid(upid);
1687         }                                        1771         }
1688                                                  1772 
1689         wo.wo_type      = type;                  1773         wo.wo_type      = type;
1690         wo.wo_pid       = pid;                   1774         wo.wo_pid       = pid;
1691         wo.wo_flags     = options | WEXITED;     1775         wo.wo_flags     = options | WEXITED;
1692         wo.wo_info      = NULL;                  1776         wo.wo_info      = NULL;
1693         wo.wo_stat      = stat_addr;             1777         wo.wo_stat      = stat_addr;
1694         wo.wo_rusage    = ru;                    1778         wo.wo_rusage    = ru;
1695         ret = do_wait(&wo);                      1779         ret = do_wait(&wo);
1696         put_pid(pid);                            1780         put_pid(pid);
1697                                                  1781 
                                                   >> 1782         /* avoid REGPARM breakage on x86: */
                                                   >> 1783         asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
1698         return ret;                              1784         return ret;
1699 }                                                1785 }
1700                                                  1786 
1701 #ifdef __ARCH_WANT_SYS_WAITPID                   1787 #ifdef __ARCH_WANT_SYS_WAITPID
1702                                                  1788 
1703 /*                                               1789 /*
1704  * sys_waitpid() remains for compatibility. w    1790  * sys_waitpid() remains for compatibility. waitpid() should be
1705  * implemented by calling sys_wait4() from li    1791  * implemented by calling sys_wait4() from libc.a.
1706  */                                              1792  */
1707 SYSCALL_DEFINE3(waitpid, pid_t, pid, int __us    1793 SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
1708 {                                                1794 {
1709         return sys_wait4(pid, stat_addr, opti    1795         return sys_wait4(pid, stat_addr, options, NULL);
1710 }                                                1796 }
1711                                                  1797 
1712 #endif                                           1798 #endif
1713                                                  1799 

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