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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/exit.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/mm.h> |
8 | #include <linux/slab.h> | |
9 | #include <linux/interrupt.h> | |
1da177e4 | 10 | #include <linux/module.h> |
c59ede7b | 11 | #include <linux/capability.h> |
1da177e4 LT |
12 | #include <linux/completion.h> |
13 | #include <linux/personality.h> | |
14 | #include <linux/tty.h> | |
6b3286ed | 15 | #include <linux/mnt_namespace.h> |
1da177e4 LT |
16 | #include <linux/key.h> |
17 | #include <linux/security.h> | |
18 | #include <linux/cpu.h> | |
19 | #include <linux/acct.h> | |
8f0ab514 | 20 | #include <linux/tsacct_kern.h> |
1da177e4 LT |
21 | #include <linux/file.h> |
22 | #include <linux/binfmts.h> | |
ab516013 | 23 | #include <linux/nsproxy.h> |
84d73786 | 24 | #include <linux/pid_namespace.h> |
1da177e4 LT |
25 | #include <linux/ptrace.h> |
26 | #include <linux/profile.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/proc_fs.h> | |
49d769d5 | 29 | #include <linux/kthread.h> |
1da177e4 | 30 | #include <linux/mempolicy.h> |
c757249a | 31 | #include <linux/taskstats_kern.h> |
ca74e92b | 32 | #include <linux/delayacct.h> |
83144186 | 33 | #include <linux/freezer.h> |
b4f48b63 | 34 | #include <linux/cgroup.h> |
1da177e4 | 35 | #include <linux/syscalls.h> |
7ed20e1a | 36 | #include <linux/signal.h> |
6a14c5c9 | 37 | #include <linux/posix-timers.h> |
9f46080c | 38 | #include <linux/cn_proc.h> |
de5097c2 | 39 | #include <linux/mutex.h> |
0771dfef | 40 | #include <linux/futex.h> |
34f192c6 | 41 | #include <linux/compat.h> |
b92ce558 | 42 | #include <linux/pipe_fs_i.h> |
fa84cb93 | 43 | #include <linux/audit.h> /* for audit_free() */ |
83cc5ed3 | 44 | #include <linux/resource.h> |
0d67a46d | 45 | #include <linux/blkdev.h> |
6eaeeaba | 46 | #include <linux/task_io_accounting_ops.h> |
1da177e4 LT |
47 | |
48 | #include <asm/uaccess.h> | |
49 | #include <asm/unistd.h> | |
50 | #include <asm/pgtable.h> | |
51 | #include <asm/mmu_context.h> | |
52 | ||
408b664a AB |
53 | static void exit_mm(struct task_struct * tsk); |
54 | ||
d839fd4d ON |
55 | static inline int task_detached(struct task_struct *p) |
56 | { | |
57 | return p->exit_signal == -1; | |
58 | } | |
59 | ||
1da177e4 LT |
60 | static void __unhash_process(struct task_struct *p) |
61 | { | |
62 | nr_threads--; | |
63 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
64 | if (thread_group_leader(p)) { |
65 | detach_pid(p, PIDTYPE_PGID); | |
66 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 67 | |
5e85d4ab | 68 | list_del_rcu(&p->tasks); |
73b9ebfe | 69 | __get_cpu_var(process_counts)--; |
1da177e4 | 70 | } |
47e65328 | 71 | list_del_rcu(&p->thread_group); |
c97d9893 | 72 | remove_parent(p); |
1da177e4 LT |
73 | } |
74 | ||
6a14c5c9 ON |
75 | /* |
76 | * This function expects the tasklist_lock write-locked. | |
77 | */ | |
78 | static void __exit_signal(struct task_struct *tsk) | |
79 | { | |
80 | struct signal_struct *sig = tsk->signal; | |
81 | struct sighand_struct *sighand; | |
82 | ||
83 | BUG_ON(!sig); | |
84 | BUG_ON(!atomic_read(&sig->count)); | |
85 | ||
86 | rcu_read_lock(); | |
87 | sighand = rcu_dereference(tsk->sighand); | |
88 | spin_lock(&sighand->siglock); | |
89 | ||
90 | posix_cpu_timers_exit(tsk); | |
91 | if (atomic_dec_and_test(&sig->count)) | |
92 | posix_cpu_timers_exit_group(tsk); | |
93 | else { | |
94 | /* | |
95 | * If there is any task waiting for the group exit | |
96 | * then notify it: | |
97 | */ | |
6db840fa | 98 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) |
6a14c5c9 | 99 | wake_up_process(sig->group_exit_task); |
6db840fa | 100 | |
6a14c5c9 ON |
101 | if (tsk == sig->curr_target) |
102 | sig->curr_target = next_thread(tsk); | |
103 | /* | |
104 | * Accumulate here the counters for all threads but the | |
105 | * group leader as they die, so they can be added into | |
106 | * the process-wide totals when those are taken. | |
107 | * The group leader stays around as a zombie as long | |
108 | * as there are other threads. When it gets reaped, | |
109 | * the exit.c code will add its counts into these totals. | |
110 | * We won't ever get here for the group leader, since it | |
111 | * will have been the last reference on the signal_struct. | |
112 | */ | |
113 | sig->utime = cputime_add(sig->utime, tsk->utime); | |
114 | sig->stime = cputime_add(sig->stime, tsk->stime); | |
9ac52315 | 115 | sig->gtime = cputime_add(sig->gtime, tsk->gtime); |
6a14c5c9 ON |
116 | sig->min_flt += tsk->min_flt; |
117 | sig->maj_flt += tsk->maj_flt; | |
118 | sig->nvcsw += tsk->nvcsw; | |
119 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
120 | sig->inblock += task_io_get_inblock(tsk); |
121 | sig->oublock += task_io_get_oublock(tsk); | |
172ba844 | 122 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
6a14c5c9 ON |
123 | sig = NULL; /* Marker for below. */ |
124 | } | |
125 | ||
5876700c ON |
126 | __unhash_process(tsk); |
127 | ||
6a14c5c9 | 128 | tsk->signal = NULL; |
a7e5328a | 129 | tsk->sighand = NULL; |
6a14c5c9 ON |
130 | spin_unlock(&sighand->siglock); |
131 | rcu_read_unlock(); | |
132 | ||
a7e5328a | 133 | __cleanup_sighand(sighand); |
6a14c5c9 ON |
134 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
135 | flush_sigqueue(&tsk->pending); | |
136 | if (sig) { | |
137 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 138 | taskstats_tgid_free(sig); |
6a14c5c9 ON |
139 | __cleanup_signal(sig); |
140 | } | |
141 | } | |
142 | ||
8c7904a0 EB |
143 | static void delayed_put_task_struct(struct rcu_head *rhp) |
144 | { | |
145 | put_task_struct(container_of(rhp, struct task_struct, rcu)); | |
146 | } | |
147 | ||
1da177e4 LT |
148 | void release_task(struct task_struct * p) |
149 | { | |
36c8b586 | 150 | struct task_struct *leader; |
1da177e4 | 151 | int zap_leader; |
1f09f974 | 152 | repeat: |
1da177e4 | 153 | atomic_dec(&p->user->processes); |
60347f67 | 154 | proc_flush_task(p); |
1da177e4 | 155 | write_lock_irq(&tasklist_lock); |
1f09f974 | 156 | ptrace_unlink(p); |
1da177e4 LT |
157 | BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); |
158 | __exit_signal(p); | |
35f5cad8 | 159 | |
1da177e4 LT |
160 | /* |
161 | * If we are the last non-leader member of the thread | |
162 | * group, and the leader is zombie, then notify the | |
163 | * group leader's parent process. (if it wants notification.) | |
164 | */ | |
165 | zap_leader = 0; | |
166 | leader = p->group_leader; | |
167 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
d839fd4d | 168 | BUG_ON(task_detached(leader)); |
1da177e4 LT |
169 | do_notify_parent(leader, leader->exit_signal); |
170 | /* | |
171 | * If we were the last child thread and the leader has | |
172 | * exited already, and the leader's parent ignores SIGCHLD, | |
173 | * then we are the one who should release the leader. | |
174 | * | |
175 | * do_notify_parent() will have marked it self-reaping in | |
176 | * that case. | |
177 | */ | |
d839fd4d | 178 | zap_leader = task_detached(leader); |
1da177e4 LT |
179 | } |
180 | ||
1da177e4 | 181 | write_unlock_irq(&tasklist_lock); |
1da177e4 | 182 | release_thread(p); |
8c7904a0 | 183 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
184 | |
185 | p = leader; | |
186 | if (unlikely(zap_leader)) | |
187 | goto repeat; | |
188 | } | |
189 | ||
1da177e4 LT |
190 | /* |
191 | * This checks not only the pgrp, but falls back on the pid if no | |
192 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
193 | * without this... | |
04a2e6a5 EB |
194 | * |
195 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 196 | */ |
04a2e6a5 | 197 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
198 | { |
199 | struct task_struct *p; | |
04a2e6a5 | 200 | struct pid *sid = NULL; |
62dfb554 | 201 | |
04a2e6a5 | 202 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 203 | if (p == NULL) |
04a2e6a5 | 204 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 205 | if (p != NULL) |
04a2e6a5 | 206 | sid = task_session(p); |
62dfb554 | 207 | |
1da177e4 LT |
208 | return sid; |
209 | } | |
210 | ||
211 | /* | |
212 | * Determine if a process group is "orphaned", according to the POSIX | |
213 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
214 | * by terminal-generated stop signals. Newly orphaned process groups are | |
215 | * to receive a SIGHUP and a SIGCONT. | |
216 | * | |
217 | * "I ask you, have you ever known what it is to be an orphan?" | |
218 | */ | |
0475ac08 | 219 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
220 | { |
221 | struct task_struct *p; | |
1da177e4 | 222 | |
0475ac08 | 223 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
05e83df6 ON |
224 | if ((p == ignored_task) || |
225 | (p->exit_state && thread_group_empty(p)) || | |
226 | is_global_init(p->real_parent)) | |
1da177e4 | 227 | continue; |
05e83df6 | 228 | |
0475ac08 | 229 | if (task_pgrp(p->real_parent) != pgrp && |
05e83df6 ON |
230 | task_session(p->real_parent) == task_session(p)) |
231 | return 0; | |
0475ac08 | 232 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
05e83df6 ON |
233 | |
234 | return 1; | |
1da177e4 LT |
235 | } |
236 | ||
3e7cd6c4 | 237 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
238 | { |
239 | int retval; | |
240 | ||
241 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 242 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
243 | read_unlock(&tasklist_lock); |
244 | ||
245 | return retval; | |
246 | } | |
247 | ||
0475ac08 | 248 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
249 | { |
250 | int retval = 0; | |
251 | struct task_struct *p; | |
252 | ||
0475ac08 | 253 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
338077e5 | 254 | if (!task_is_stopped(p)) |
1da177e4 | 255 | continue; |
1da177e4 LT |
256 | retval = 1; |
257 | break; | |
0475ac08 | 258 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
259 | return retval; |
260 | } | |
261 | ||
f49ee505 ON |
262 | /* |
263 | * Check to see if any process groups have become orphaned as | |
264 | * a result of our exiting, and if they have any stopped jobs, | |
265 | * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
266 | */ | |
267 | static void | |
268 | kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) | |
269 | { | |
270 | struct pid *pgrp = task_pgrp(tsk); | |
271 | struct task_struct *ignored_task = tsk; | |
272 | ||
273 | if (!parent) | |
274 | /* exit: our father is in a different pgrp than | |
275 | * we are and we were the only connection outside. | |
276 | */ | |
277 | parent = tsk->real_parent; | |
278 | else | |
279 | /* reparent: our child is in a different pgrp than | |
280 | * we are, and it was the only connection outside. | |
281 | */ | |
282 | ignored_task = NULL; | |
283 | ||
284 | if (task_pgrp(parent) != pgrp && | |
285 | task_session(parent) == task_session(tsk) && | |
286 | will_become_orphaned_pgrp(pgrp, ignored_task) && | |
287 | has_stopped_jobs(pgrp)) { | |
288 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
289 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
290 | } | |
291 | } | |
292 | ||
1da177e4 | 293 | /** |
49d769d5 | 294 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
295 | * |
296 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
297 | * it ever exits, it should generally reparent itself to kthreadd so it |
298 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
299 | * |
300 | * The various task state such as scheduling policy and priority may have | |
301 | * been inherited from a user process, so we reset them to sane values here. | |
302 | * | |
49d769d5 | 303 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 304 | */ |
49d769d5 | 305 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
306 | { |
307 | write_lock_irq(&tasklist_lock); | |
308 | ||
309 | ptrace_unlink(current); | |
310 | /* Reparent to init */ | |
9b678ece | 311 | remove_parent(current); |
49d769d5 | 312 | current->real_parent = current->parent = kthreadd_task; |
9b678ece | 313 | add_parent(current); |
1da177e4 LT |
314 | |
315 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
316 | current->exit_signal = SIGCHLD; | |
317 | ||
e05606d3 | 318 | if (task_nice(current) < 0) |
1da177e4 LT |
319 | set_user_nice(current, 0); |
320 | /* cpus_allowed? */ | |
321 | /* rt_priority? */ | |
322 | /* signals? */ | |
323 | security_task_reparent_to_init(current); | |
324 | memcpy(current->signal->rlim, init_task.signal->rlim, | |
325 | sizeof(current->signal->rlim)); | |
326 | atomic_inc(&(INIT_USER->__count)); | |
327 | write_unlock_irq(&tasklist_lock); | |
328 | switch_uid(INIT_USER); | |
329 | } | |
330 | ||
8520d7c7 | 331 | void __set_special_pids(struct pid *pid) |
1da177e4 | 332 | { |
e19f247a | 333 | struct task_struct *curr = current->group_leader; |
8520d7c7 | 334 | pid_t nr = pid_nr(pid); |
1da177e4 | 335 | |
8520d7c7 | 336 | if (task_session(curr) != pid) { |
7d8da096 | 337 | change_pid(curr, PIDTYPE_SID, pid); |
8520d7c7 | 338 | set_task_session(curr, nr); |
1da177e4 | 339 | } |
8520d7c7 | 340 | if (task_pgrp(curr) != pid) { |
7d8da096 | 341 | change_pid(curr, PIDTYPE_PGID, pid); |
8520d7c7 | 342 | set_task_pgrp(curr, nr); |
1da177e4 LT |
343 | } |
344 | } | |
345 | ||
8520d7c7 | 346 | static void set_special_pids(struct pid *pid) |
1da177e4 LT |
347 | { |
348 | write_lock_irq(&tasklist_lock); | |
8520d7c7 | 349 | __set_special_pids(pid); |
1da177e4 LT |
350 | write_unlock_irq(&tasklist_lock); |
351 | } | |
352 | ||
353 | /* | |
354 | * Let kernel threads use this to say that they | |
355 | * allow a certain signal (since daemonize() will | |
356 | * have disabled all of them by default). | |
357 | */ | |
358 | int allow_signal(int sig) | |
359 | { | |
7ed20e1a | 360 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
361 | return -EINVAL; |
362 | ||
363 | spin_lock_irq(¤t->sighand->siglock); | |
364 | sigdelset(¤t->blocked, sig); | |
365 | if (!current->mm) { | |
366 | /* Kernel threads handle their own signals. | |
367 | Let the signal code know it'll be handled, so | |
368 | that they don't get converted to SIGKILL or | |
369 | just silently dropped */ | |
370 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
371 | } | |
372 | recalc_sigpending(); | |
373 | spin_unlock_irq(¤t->sighand->siglock); | |
374 | return 0; | |
375 | } | |
376 | ||
377 | EXPORT_SYMBOL(allow_signal); | |
378 | ||
379 | int disallow_signal(int sig) | |
380 | { | |
7ed20e1a | 381 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
382 | return -EINVAL; |
383 | ||
384 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 385 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
386 | recalc_sigpending(); |
387 | spin_unlock_irq(¤t->sighand->siglock); | |
388 | return 0; | |
389 | } | |
390 | ||
391 | EXPORT_SYMBOL(disallow_signal); | |
392 | ||
393 | /* | |
394 | * Put all the gunge required to become a kernel thread without | |
395 | * attached user resources in one place where it belongs. | |
396 | */ | |
397 | ||
398 | void daemonize(const char *name, ...) | |
399 | { | |
400 | va_list args; | |
401 | struct fs_struct *fs; | |
402 | sigset_t blocked; | |
403 | ||
404 | va_start(args, name); | |
405 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
406 | va_end(args); | |
407 | ||
408 | /* | |
409 | * If we were started as result of loading a module, close all of the | |
410 | * user space pages. We don't need them, and if we didn't close them | |
411 | * they would be locked into memory. | |
412 | */ | |
413 | exit_mm(current); | |
83144186 RW |
414 | /* |
415 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
416 | * or suspend transition begins right now. | |
417 | */ | |
418 | current->flags |= PF_NOFREEZE; | |
1da177e4 | 419 | |
8520d7c7 ON |
420 | if (current->nsproxy != &init_nsproxy) { |
421 | get_nsproxy(&init_nsproxy); | |
422 | switch_task_namespaces(current, &init_nsproxy); | |
423 | } | |
297bd42b | 424 | set_special_pids(&init_struct_pid); |
24ec839c | 425 | proc_clear_tty(current); |
1da177e4 LT |
426 | |
427 | /* Block and flush all signals */ | |
428 | sigfillset(&blocked); | |
429 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
430 | flush_signals(current); | |
431 | ||
432 | /* Become as one with the init task */ | |
433 | ||
434 | exit_fs(current); /* current->fs->count--; */ | |
435 | fs = init_task.fs; | |
436 | current->fs = fs; | |
437 | atomic_inc(&fs->count); | |
ab516013 | 438 | |
d4c5e41f | 439 | exit_files(current); |
1da177e4 LT |
440 | current->files = init_task.files; |
441 | atomic_inc(¤t->files->count); | |
442 | ||
49d769d5 | 443 | reparent_to_kthreadd(); |
1da177e4 LT |
444 | } |
445 | ||
446 | EXPORT_SYMBOL(daemonize); | |
447 | ||
858119e1 | 448 | static void close_files(struct files_struct * files) |
1da177e4 LT |
449 | { |
450 | int i, j; | |
badf1662 | 451 | struct fdtable *fdt; |
1da177e4 LT |
452 | |
453 | j = 0; | |
4fb3a538 DS |
454 | |
455 | /* | |
456 | * It is safe to dereference the fd table without RCU or | |
457 | * ->file_lock because this is the last reference to the | |
458 | * files structure. | |
459 | */ | |
badf1662 | 460 | fdt = files_fdtable(files); |
1da177e4 LT |
461 | for (;;) { |
462 | unsigned long set; | |
463 | i = j * __NFDBITS; | |
bbea9f69 | 464 | if (i >= fdt->max_fds) |
1da177e4 | 465 | break; |
badf1662 | 466 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
467 | while (set) { |
468 | if (set & 1) { | |
badf1662 | 469 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 470 | if (file) { |
1da177e4 | 471 | filp_close(file, files); |
944be0b2 IM |
472 | cond_resched(); |
473 | } | |
1da177e4 LT |
474 | } |
475 | i++; | |
476 | set >>= 1; | |
477 | } | |
478 | } | |
479 | } | |
480 | ||
481 | struct files_struct *get_files_struct(struct task_struct *task) | |
482 | { | |
483 | struct files_struct *files; | |
484 | ||
485 | task_lock(task); | |
486 | files = task->files; | |
487 | if (files) | |
488 | atomic_inc(&files->count); | |
489 | task_unlock(task); | |
490 | ||
491 | return files; | |
492 | } | |
493 | ||
7ad5b3a5 | 494 | void put_files_struct(struct files_struct *files) |
1da177e4 | 495 | { |
badf1662 DS |
496 | struct fdtable *fdt; |
497 | ||
1da177e4 LT |
498 | if (atomic_dec_and_test(&files->count)) { |
499 | close_files(files); | |
500 | /* | |
501 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
502 | * If the fdtable was embedded, pass files for freeing |
503 | * at the end of the RCU grace period. Otherwise, | |
504 | * you can free files immediately. | |
1da177e4 | 505 | */ |
badf1662 | 506 | fdt = files_fdtable(files); |
4fd45812 | 507 | if (fdt != &files->fdtab) |
ab2af1f5 | 508 | kmem_cache_free(files_cachep, files); |
01b2d93c | 509 | free_fdtable(fdt); |
1da177e4 LT |
510 | } |
511 | } | |
512 | ||
3b125388 | 513 | void reset_files_struct(struct files_struct *files) |
3b9b8ab6 | 514 | { |
3b125388 | 515 | struct task_struct *tsk = current; |
3b9b8ab6 KK |
516 | struct files_struct *old; |
517 | ||
518 | old = tsk->files; | |
519 | task_lock(tsk); | |
520 | tsk->files = files; | |
521 | task_unlock(tsk); | |
522 | put_files_struct(old); | |
523 | } | |
3b9b8ab6 | 524 | |
1ec7f1dd | 525 | void exit_files(struct task_struct *tsk) |
1da177e4 LT |
526 | { |
527 | struct files_struct * files = tsk->files; | |
528 | ||
529 | if (files) { | |
530 | task_lock(tsk); | |
531 | tsk->files = NULL; | |
532 | task_unlock(tsk); | |
533 | put_files_struct(files); | |
534 | } | |
535 | } | |
536 | ||
1ec7f1dd | 537 | void put_fs_struct(struct fs_struct *fs) |
1da177e4 LT |
538 | { |
539 | /* No need to hold fs->lock if we are killing it */ | |
540 | if (atomic_dec_and_test(&fs->count)) { | |
6ac08c39 JB |
541 | path_put(&fs->root); |
542 | path_put(&fs->pwd); | |
543 | if (fs->altroot.dentry) | |
544 | path_put(&fs->altroot); | |
1da177e4 LT |
545 | kmem_cache_free(fs_cachep, fs); |
546 | } | |
547 | } | |
548 | ||
1ec7f1dd | 549 | void exit_fs(struct task_struct *tsk) |
1da177e4 LT |
550 | { |
551 | struct fs_struct * fs = tsk->fs; | |
552 | ||
553 | if (fs) { | |
554 | task_lock(tsk); | |
555 | tsk->fs = NULL; | |
556 | task_unlock(tsk); | |
1ec7f1dd | 557 | put_fs_struct(fs); |
1da177e4 LT |
558 | } |
559 | } | |
560 | ||
1da177e4 LT |
561 | EXPORT_SYMBOL_GPL(exit_fs); |
562 | ||
cf475ad2 BS |
563 | #ifdef CONFIG_MM_OWNER |
564 | /* | |
565 | * Task p is exiting and it owned mm, lets find a new owner for it | |
566 | */ | |
567 | static inline int | |
568 | mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) | |
569 | { | |
570 | /* | |
571 | * If there are other users of the mm and the owner (us) is exiting | |
572 | * we need to find a new owner to take on the responsibility. | |
573 | */ | |
574 | if (!mm) | |
575 | return 0; | |
576 | if (atomic_read(&mm->mm_users) <= 1) | |
577 | return 0; | |
578 | if (mm->owner != p) | |
579 | return 0; | |
580 | return 1; | |
581 | } | |
582 | ||
583 | void mm_update_next_owner(struct mm_struct *mm) | |
584 | { | |
585 | struct task_struct *c, *g, *p = current; | |
586 | ||
587 | retry: | |
588 | if (!mm_need_new_owner(mm, p)) | |
589 | return; | |
590 | ||
591 | read_lock(&tasklist_lock); | |
592 | /* | |
593 | * Search in the children | |
594 | */ | |
595 | list_for_each_entry(c, &p->children, sibling) { | |
596 | if (c->mm == mm) | |
597 | goto assign_new_owner; | |
598 | } | |
599 | ||
600 | /* | |
601 | * Search in the siblings | |
602 | */ | |
603 | list_for_each_entry(c, &p->parent->children, sibling) { | |
604 | if (c->mm == mm) | |
605 | goto assign_new_owner; | |
606 | } | |
607 | ||
608 | /* | |
609 | * Search through everything else. We should not get | |
610 | * here often | |
611 | */ | |
612 | do_each_thread(g, c) { | |
613 | if (c->mm == mm) | |
614 | goto assign_new_owner; | |
615 | } while_each_thread(g, c); | |
616 | ||
617 | read_unlock(&tasklist_lock); | |
618 | return; | |
619 | ||
620 | assign_new_owner: | |
621 | BUG_ON(c == p); | |
622 | get_task_struct(c); | |
623 | /* | |
624 | * The task_lock protects c->mm from changing. | |
625 | * We always want mm->owner->mm == mm | |
626 | */ | |
627 | task_lock(c); | |
628 | /* | |
629 | * Delay read_unlock() till we have the task_lock() | |
630 | * to ensure that c does not slip away underneath us | |
631 | */ | |
632 | read_unlock(&tasklist_lock); | |
633 | if (c->mm != mm) { | |
634 | task_unlock(c); | |
635 | put_task_struct(c); | |
636 | goto retry; | |
637 | } | |
638 | cgroup_mm_owner_callbacks(mm->owner, c); | |
639 | mm->owner = c; | |
640 | task_unlock(c); | |
641 | put_task_struct(c); | |
642 | } | |
643 | #endif /* CONFIG_MM_OWNER */ | |
644 | ||
1da177e4 LT |
645 | /* |
646 | * Turn us into a lazy TLB process if we | |
647 | * aren't already.. | |
648 | */ | |
408b664a | 649 | static void exit_mm(struct task_struct * tsk) |
1da177e4 LT |
650 | { |
651 | struct mm_struct *mm = tsk->mm; | |
652 | ||
653 | mm_release(tsk, mm); | |
654 | if (!mm) | |
655 | return; | |
656 | /* | |
657 | * Serialize with any possible pending coredump. | |
658 | * We must hold mmap_sem around checking core_waiters | |
659 | * and clearing tsk->mm. The core-inducing thread | |
660 | * will increment core_waiters for each thread in the | |
661 | * group with ->mm != NULL. | |
662 | */ | |
663 | down_read(&mm->mmap_sem); | |
664 | if (mm->core_waiters) { | |
665 | up_read(&mm->mmap_sem); | |
666 | down_write(&mm->mmap_sem); | |
667 | if (!--mm->core_waiters) | |
668 | complete(mm->core_startup_done); | |
669 | up_write(&mm->mmap_sem); | |
670 | ||
671 | wait_for_completion(&mm->core_done); | |
672 | down_read(&mm->mmap_sem); | |
673 | } | |
674 | atomic_inc(&mm->mm_count); | |
125e1874 | 675 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
676 | /* more a memory barrier than a real lock */ |
677 | task_lock(tsk); | |
678 | tsk->mm = NULL; | |
679 | up_read(&mm->mmap_sem); | |
680 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
681 | /* We don't want this task to be frozen prematurely */ |
682 | clear_freeze_flag(tsk); | |
1da177e4 | 683 | task_unlock(tsk); |
cf475ad2 | 684 | mm_update_next_owner(mm); |
1da177e4 LT |
685 | mmput(mm); |
686 | } | |
687 | ||
36c8b586 IM |
688 | static void |
689 | reparent_thread(struct task_struct *p, struct task_struct *father, int traced) | |
1da177e4 | 690 | { |
241ceee0 ON |
691 | if (p->pdeath_signal) |
692 | /* We already hold the tasklist_lock here. */ | |
693 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
694 | ||
1da177e4 LT |
695 | /* Move the child from its dying parent to the new one. */ |
696 | if (unlikely(traced)) { | |
697 | /* Preserve ptrace links if someone else is tracing this child. */ | |
698 | list_del_init(&p->ptrace_list); | |
53b6f9fb | 699 | if (ptrace_reparented(p)) |
1da177e4 LT |
700 | list_add(&p->ptrace_list, &p->real_parent->ptrace_children); |
701 | } else { | |
702 | /* If this child is being traced, then we're the one tracing it | |
703 | * anyway, so let go of it. | |
704 | */ | |
705 | p->ptrace = 0; | |
6ac781b1 | 706 | remove_parent(p); |
1da177e4 | 707 | p->parent = p->real_parent; |
6ac781b1 | 708 | add_parent(p); |
1da177e4 | 709 | |
338077e5 | 710 | if (task_is_traced(p)) { |
1da177e4 LT |
711 | /* |
712 | * If it was at a trace stop, turn it into | |
713 | * a normal stop since it's no longer being | |
714 | * traced. | |
715 | */ | |
716 | ptrace_untrace(p); | |
717 | } | |
718 | } | |
719 | ||
b2b2cbc4 EB |
720 | /* If this is a threaded reparent there is no need to |
721 | * notify anyone anything has happened. | |
722 | */ | |
376e1d25 | 723 | if (same_thread_group(p->real_parent, father)) |
b2b2cbc4 EB |
724 | return; |
725 | ||
726 | /* We don't want people slaying init. */ | |
d839fd4d | 727 | if (!task_detached(p)) |
b2b2cbc4 | 728 | p->exit_signal = SIGCHLD; |
b2b2cbc4 EB |
729 | |
730 | /* If we'd notified the old parent about this child's death, | |
731 | * also notify the new parent. | |
732 | */ | |
733 | if (!traced && p->exit_state == EXIT_ZOMBIE && | |
d839fd4d | 734 | !task_detached(p) && thread_group_empty(p)) |
b2b2cbc4 EB |
735 | do_notify_parent(p, p->exit_signal); |
736 | ||
f49ee505 | 737 | kill_orphaned_pgrp(p, father); |
1da177e4 LT |
738 | } |
739 | ||
740 | /* | |
741 | * When we die, we re-parent all our children. | |
742 | * Try to give them to another thread in our thread | |
743 | * group, and if no such member exists, give it to | |
84d73786 SB |
744 | * the child reaper process (ie "init") in our pid |
745 | * space. | |
1da177e4 | 746 | */ |
762a24be | 747 | static void forget_original_parent(struct task_struct *father) |
1da177e4 | 748 | { |
03ff1797 | 749 | struct task_struct *p, *n, *reaper = father; |
762a24be ON |
750 | struct list_head ptrace_dead; |
751 | ||
752 | INIT_LIST_HEAD(&ptrace_dead); | |
753 | ||
754 | write_lock_irq(&tasklist_lock); | |
1da177e4 LT |
755 | |
756 | do { | |
757 | reaper = next_thread(reaper); | |
758 | if (reaper == father) { | |
88f21d81 | 759 | reaper = task_child_reaper(father); |
1da177e4 LT |
760 | break; |
761 | } | |
762a24be | 762 | } while (reaper->flags & PF_EXITING); |
1da177e4 LT |
763 | |
764 | /* | |
765 | * There are only two places where our children can be: | |
766 | * | |
767 | * - in our child list | |
768 | * - in our ptraced child list | |
769 | * | |
770 | * Search them and reparent children. | |
771 | */ | |
03ff1797 | 772 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
1da177e4 | 773 | int ptrace; |
1da177e4 LT |
774 | |
775 | ptrace = p->ptrace; | |
776 | ||
777 | /* if father isn't the real parent, then ptrace must be enabled */ | |
778 | BUG_ON(father != p->real_parent && !ptrace); | |
779 | ||
780 | if (father == p->real_parent) { | |
781 | /* reparent with a reaper, real father it's us */ | |
84eb646b | 782 | p->real_parent = reaper; |
1da177e4 LT |
783 | reparent_thread(p, father, 0); |
784 | } else { | |
785 | /* reparent ptraced task to its real parent */ | |
786 | __ptrace_unlink (p); | |
d839fd4d | 787 | if (p->exit_state == EXIT_ZOMBIE && !task_detached(p) && |
1da177e4 LT |
788 | thread_group_empty(p)) |
789 | do_notify_parent(p, p->exit_signal); | |
790 | } | |
791 | ||
792 | /* | |
d839fd4d ON |
793 | * if the ptraced child is a detached zombie we must collect |
794 | * it before we exit, or it will remain zombie forever since | |
795 | * we prevented it from self-reap itself while it was being | |
796 | * traced by us, to be able to see it in wait4. | |
1da177e4 | 797 | */ |
d839fd4d | 798 | if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && task_detached(p))) |
762a24be | 799 | list_add(&p->ptrace_list, &ptrace_dead); |
1da177e4 | 800 | } |
762a24be | 801 | |
03ff1797 | 802 | list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) { |
84eb646b | 803 | p->real_parent = reaper; |
1da177e4 LT |
804 | reparent_thread(p, father, 1); |
805 | } | |
762a24be ON |
806 | |
807 | write_unlock_irq(&tasklist_lock); | |
808 | BUG_ON(!list_empty(&father->children)); | |
809 | BUG_ON(!list_empty(&father->ptrace_children)); | |
810 | ||
811 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_list) { | |
812 | list_del_init(&p->ptrace_list); | |
813 | release_task(p); | |
814 | } | |
815 | ||
1da177e4 LT |
816 | } |
817 | ||
818 | /* | |
819 | * Send signals to all our closest relatives so that they know | |
820 | * to properly mourn us.. | |
821 | */ | |
821c7de7 | 822 | static void exit_notify(struct task_struct *tsk, int group_dead) |
1da177e4 LT |
823 | { |
824 | int state; | |
1da177e4 | 825 | |
1da177e4 LT |
826 | /* |
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 | */ | |
762a24be | 834 | forget_original_parent(tsk); |
2e4a7072 | 835 | exit_task_namespaces(tsk); |
1da177e4 | 836 | |
762a24be | 837 | write_lock_irq(&tasklist_lock); |
821c7de7 ON |
838 | if (group_dead) |
839 | kill_orphaned_pgrp(tsk->group_leader, NULL); | |
1da177e4 | 840 | |
24728448 | 841 | /* Let father know we died |
1da177e4 LT |
842 | * |
843 | * Thread signals are configurable, but you aren't going to use | |
d4c5e41f | 844 | * that to send signals to arbitary processes. |
1da177e4 LT |
845 | * That stops right now. |
846 | * | |
847 | * If the parent exec id doesn't match the exec id we saved | |
848 | * when we started then we know the parent has changed security | |
849 | * domain. | |
850 | * | |
851 | * If our self_exec id doesn't match our parent_exec_id then | |
852 | * we have changed execution domain as these two values started | |
853 | * the same after a fork. | |
1da177e4 | 854 | */ |
d839fd4d | 855 | if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) && |
f49ee505 | 856 | (tsk->parent_exec_id != tsk->real_parent->self_exec_id || |
d839fd4d ON |
857 | tsk->self_exec_id != tsk->parent_exec_id) && |
858 | !capable(CAP_KILL)) | |
1da177e4 LT |
859 | tsk->exit_signal = SIGCHLD; |
860 | ||
1da177e4 LT |
861 | /* If something other than our normal parent is ptracing us, then |
862 | * send it a SIGCHLD instead of honoring exit_signal. exit_signal | |
863 | * only has special meaning to our real parent. | |
864 | */ | |
d839fd4d | 865 | if (!task_detached(tsk) && thread_group_empty(tsk)) { |
53b6f9fb ON |
866 | int signal = ptrace_reparented(tsk) ? |
867 | SIGCHLD : tsk->exit_signal; | |
1da177e4 LT |
868 | do_notify_parent(tsk, signal); |
869 | } else if (tsk->ptrace) { | |
870 | do_notify_parent(tsk, SIGCHLD); | |
871 | } | |
872 | ||
873 | state = EXIT_ZOMBIE; | |
d839fd4d | 874 | if (task_detached(tsk) && likely(!tsk->ptrace)) |
1da177e4 LT |
875 | state = EXIT_DEAD; |
876 | tsk->exit_state = state; | |
877 | ||
2800d8d1 | 878 | /* mt-exec, de_thread() is waiting for us */ |
6db840fa ON |
879 | if (thread_group_leader(tsk) && |
880 | tsk->signal->notify_count < 0 && | |
881 | tsk->signal->group_exit_task) | |
882 | wake_up_process(tsk->signal->group_exit_task); | |
883 | ||
1da177e4 LT |
884 | write_unlock_irq(&tasklist_lock); |
885 | ||
1da177e4 LT |
886 | /* If the process is dead, release it - nobody will wait for it */ |
887 | if (state == EXIT_DEAD) | |
888 | release_task(tsk); | |
1da177e4 LT |
889 | } |
890 | ||
e18eecb8 JD |
891 | #ifdef CONFIG_DEBUG_STACK_USAGE |
892 | static void check_stack_usage(void) | |
893 | { | |
894 | static DEFINE_SPINLOCK(low_water_lock); | |
895 | static int lowest_to_date = THREAD_SIZE; | |
896 | unsigned long *n = end_of_stack(current); | |
897 | unsigned long free; | |
898 | ||
899 | while (*n == 0) | |
900 | n++; | |
901 | free = (unsigned long)n - (unsigned long)end_of_stack(current); | |
902 | ||
903 | if (free >= lowest_to_date) | |
904 | return; | |
905 | ||
906 | spin_lock(&low_water_lock); | |
907 | if (free < lowest_to_date) { | |
908 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
909 | "left\n", | |
910 | current->comm, free); | |
911 | lowest_to_date = free; | |
912 | } | |
913 | spin_unlock(&low_water_lock); | |
914 | } | |
915 | #else | |
916 | static inline void check_stack_usage(void) {} | |
917 | #endif | |
918 | ||
84eb646b ON |
919 | static inline void exit_child_reaper(struct task_struct *tsk) |
920 | { | |
88f21d81 | 921 | if (likely(tsk->group_leader != task_child_reaper(tsk))) |
84eb646b ON |
922 | return; |
923 | ||
3eb07c8c SB |
924 | if (tsk->nsproxy->pid_ns == &init_pid_ns) |
925 | panic("Attempted to kill init!"); | |
926 | ||
927 | /* | |
928 | * @tsk is the last thread in the 'cgroup-init' and is exiting. | |
929 | * Terminate all remaining processes in the namespace and reap them | |
930 | * before exiting @tsk. | |
931 | * | |
932 | * Note that @tsk (last thread of cgroup-init) may not necessarily | |
933 | * be the child-reaper (i.e main thread of cgroup-init) of the | |
934 | * namespace i.e the child_reaper may have already exited. | |
935 | * | |
936 | * Even after a child_reaper exits, we let it inherit orphaned children, | |
937 | * because, pid_ns->child_reaper remains valid as long as there is | |
938 | * at least one living sub-thread in the cgroup init. | |
939 | ||
940 | * This living sub-thread of the cgroup-init will be notified when | |
941 | * a child inherited by the 'child-reaper' exits (do_notify_parent() | |
942 | * uses __group_send_sig_info()). Further, when reaping child processes, | |
943 | * do_wait() iterates over children of all living sub threads. | |
944 | ||
945 | * i.e even though 'child_reaper' thread is listed as the parent of the | |
946 | * orphaned children, any living sub-thread in the cgroup-init can | |
947 | * perform the role of the child_reaper. | |
948 | */ | |
949 | zap_pid_ns_processes(tsk->nsproxy->pid_ns); | |
84eb646b ON |
950 | } |
951 | ||
7ad5b3a5 | 952 | NORET_TYPE void do_exit(long code) |
1da177e4 LT |
953 | { |
954 | struct task_struct *tsk = current; | |
955 | int group_dead; | |
956 | ||
957 | profile_task_exit(tsk); | |
958 | ||
22e2c507 JA |
959 | WARN_ON(atomic_read(&tsk->fs_excl)); |
960 | ||
1da177e4 LT |
961 | if (unlikely(in_interrupt())) |
962 | panic("Aiee, killing interrupt handler!"); | |
963 | if (unlikely(!tsk->pid)) | |
964 | panic("Attempted to kill the idle task!"); | |
1da177e4 LT |
965 | |
966 | if (unlikely(current->ptrace & PT_TRACE_EXIT)) { | |
967 | current->ptrace_message = code; | |
968 | ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); | |
969 | } | |
970 | ||
df164db5 AN |
971 | /* |
972 | * We're taking recursive faults here in do_exit. Safest is to just | |
973 | * leave this task alone and wait for reboot. | |
974 | */ | |
975 | if (unlikely(tsk->flags & PF_EXITING)) { | |
976 | printk(KERN_ALERT | |
977 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
978 | /* |
979 | * We can do this unlocked here. The futex code uses | |
980 | * this flag just to verify whether the pi state | |
981 | * cleanup has been done or not. In the worst case it | |
982 | * loops once more. We pretend that the cleanup was | |
983 | * done as there is no way to return. Either the | |
984 | * OWNER_DIED bit is set by now or we push the blocked | |
985 | * task into the wait for ever nirwana as well. | |
986 | */ | |
987 | tsk->flags |= PF_EXITPIDONE; | |
afc847b7 AV |
988 | if (tsk->io_context) |
989 | exit_io_context(); | |
df164db5 AN |
990 | set_current_state(TASK_UNINTERRUPTIBLE); |
991 | schedule(); | |
992 | } | |
993 | ||
d12619b5 | 994 | exit_signals(tsk); /* sets PF_EXITING */ |
778e9a9c AK |
995 | /* |
996 | * tsk->flags are checked in the futex code to protect against | |
997 | * an exiting task cleaning up the robust pi futexes. | |
998 | */ | |
d2ee7198 ON |
999 | smp_mb(); |
1000 | spin_unlock_wait(&tsk->pi_lock); | |
1da177e4 | 1001 | |
1da177e4 LT |
1002 | if (unlikely(in_atomic())) |
1003 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
ba25f9dc | 1004 | current->comm, task_pid_nr(current), |
1da177e4 LT |
1005 | preempt_count()); |
1006 | ||
1007 | acct_update_integrals(tsk); | |
365e9c87 HD |
1008 | if (tsk->mm) { |
1009 | update_hiwater_rss(tsk->mm); | |
1010 | update_hiwater_vm(tsk->mm); | |
1011 | } | |
1da177e4 | 1012 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 1013 | if (group_dead) { |
84eb646b | 1014 | exit_child_reaper(tsk); |
778e9a9c | 1015 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 1016 | exit_itimers(tsk->signal); |
c3068951 | 1017 | } |
f6ec29a4 | 1018 | acct_collect(code, group_dead); |
42b2dd0a | 1019 | #ifdef CONFIG_FUTEX |
0771dfef IM |
1020 | if (unlikely(tsk->robust_list)) |
1021 | exit_robust_list(tsk); | |
42b2dd0a | 1022 | #ifdef CONFIG_COMPAT |
34f192c6 IM |
1023 | if (unlikely(tsk->compat_robust_list)) |
1024 | compat_exit_robust_list(tsk); | |
42b2dd0a | 1025 | #endif |
34f192c6 | 1026 | #endif |
522ed776 MT |
1027 | if (group_dead) |
1028 | tty_audit_exit(); | |
fa84cb93 AV |
1029 | if (unlikely(tsk->audit_context)) |
1030 | audit_free(tsk); | |
115085ea | 1031 | |
f2ab6d88 | 1032 | tsk->exit_code = code; |
115085ea | 1033 | taskstats_exit(tsk, group_dead); |
c757249a | 1034 | |
1da177e4 LT |
1035 | exit_mm(tsk); |
1036 | ||
0e464814 | 1037 | if (group_dead) |
f6ec29a4 | 1038 | acct_process(); |
1da177e4 | 1039 | exit_sem(tsk); |
1ec7f1dd AV |
1040 | exit_files(tsk); |
1041 | exit_fs(tsk); | |
e18eecb8 | 1042 | check_stack_usage(); |
1da177e4 | 1043 | exit_thread(); |
b4f48b63 | 1044 | cgroup_exit(tsk, 1); |
1da177e4 LT |
1045 | exit_keys(tsk); |
1046 | ||
1047 | if (group_dead && tsk->signal->leader) | |
1048 | disassociate_ctty(1); | |
1049 | ||
a1261f54 | 1050 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
1051 | if (tsk->binfmt) |
1052 | module_put(tsk->binfmt->module); | |
1053 | ||
9f46080c | 1054 | proc_exit_connector(tsk); |
821c7de7 | 1055 | exit_notify(tsk, group_dead); |
1da177e4 | 1056 | #ifdef CONFIG_NUMA |
f0be3d32 | 1057 | mpol_put(tsk->mempolicy); |
1da177e4 LT |
1058 | tsk->mempolicy = NULL; |
1059 | #endif | |
42b2dd0a | 1060 | #ifdef CONFIG_FUTEX |
c87e2837 IM |
1061 | /* |
1062 | * This must happen late, after the PID is not | |
1063 | * hashed anymore: | |
1064 | */ | |
1065 | if (unlikely(!list_empty(&tsk->pi_state_list))) | |
1066 | exit_pi_state_list(tsk); | |
1067 | if (unlikely(current->pi_state_cache)) | |
1068 | kfree(current->pi_state_cache); | |
42b2dd0a | 1069 | #endif |
de5097c2 | 1070 | /* |
9a11b49a | 1071 | * Make sure we are holding no locks: |
de5097c2 | 1072 | */ |
9a11b49a | 1073 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1074 | /* |
1075 | * We can do this unlocked here. The futex code uses this flag | |
1076 | * just to verify whether the pi state cleanup has been done | |
1077 | * or not. In the worst case it loops once more. | |
1078 | */ | |
1079 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1080 | |
afc847b7 AV |
1081 | if (tsk->io_context) |
1082 | exit_io_context(); | |
1083 | ||
b92ce558 JA |
1084 | if (tsk->splice_pipe) |
1085 | __free_pipe_info(tsk->splice_pipe); | |
1086 | ||
7407251a | 1087 | preempt_disable(); |
55a101f8 | 1088 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1089 | tsk->state = TASK_DEAD; |
7407251a | 1090 | |
1da177e4 LT |
1091 | schedule(); |
1092 | BUG(); | |
1093 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1094 | for (;;) |
1095 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1096 | } |
1097 | ||
012914da RA |
1098 | EXPORT_SYMBOL_GPL(do_exit); |
1099 | ||
1da177e4 LT |
1100 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1101 | { | |
1102 | if (comp) | |
1103 | complete(comp); | |
55a101f8 | 1104 | |
1da177e4 LT |
1105 | do_exit(code); |
1106 | } | |
1107 | ||
1108 | EXPORT_SYMBOL(complete_and_exit); | |
1109 | ||
1110 | asmlinkage long sys_exit(int error_code) | |
1111 | { | |
1112 | do_exit((error_code&0xff)<<8); | |
1113 | } | |
1114 | ||
1da177e4 LT |
1115 | /* |
1116 | * Take down every thread in the group. This is called by fatal signals | |
1117 | * as well as by sys_exit_group (below). | |
1118 | */ | |
1119 | NORET_TYPE void | |
1120 | do_group_exit(int exit_code) | |
1121 | { | |
bfc4b089 ON |
1122 | struct signal_struct *sig = current->signal; |
1123 | ||
1da177e4 LT |
1124 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
1125 | ||
bfc4b089 ON |
1126 | if (signal_group_exit(sig)) |
1127 | exit_code = sig->group_exit_code; | |
1da177e4 | 1128 | else if (!thread_group_empty(current)) { |
1da177e4 | 1129 | struct sighand_struct *const sighand = current->sighand; |
1da177e4 | 1130 | spin_lock_irq(&sighand->siglock); |
ed5d2cac | 1131 | if (signal_group_exit(sig)) |
1da177e4 LT |
1132 | /* Another thread got here before we took the lock. */ |
1133 | exit_code = sig->group_exit_code; | |
1134 | else { | |
1da177e4 | 1135 | sig->group_exit_code = exit_code; |
ed5d2cac | 1136 | sig->flags = SIGNAL_GROUP_EXIT; |
1da177e4 LT |
1137 | zap_other_threads(current); |
1138 | } | |
1139 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1140 | } |
1141 | ||
1142 | do_exit(exit_code); | |
1143 | /* NOTREACHED */ | |
1144 | } | |
1145 | ||
1146 | /* | |
1147 | * this kills every thread in the thread group. Note that any externally | |
1148 | * wait4()-ing process will get the correct exit code - even if this | |
1149 | * thread is not the thread group leader. | |
1150 | */ | |
1151 | asmlinkage void sys_exit_group(int error_code) | |
1152 | { | |
1153 | do_group_exit((error_code & 0xff) << 8); | |
1154 | } | |
1155 | ||
161550d7 EB |
1156 | static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) |
1157 | { | |
1158 | struct pid *pid = NULL; | |
1159 | if (type == PIDTYPE_PID) | |
1160 | pid = task->pids[type].pid; | |
1161 | else if (type < PIDTYPE_MAX) | |
1162 | pid = task->group_leader->pids[type].pid; | |
1163 | return pid; | |
1164 | } | |
1165 | ||
1166 | static int eligible_child(enum pid_type type, struct pid *pid, int options, | |
1167 | struct task_struct *p) | |
1da177e4 | 1168 | { |
73243284 RM |
1169 | int err; |
1170 | ||
161550d7 EB |
1171 | if (type < PIDTYPE_MAX) { |
1172 | if (task_pid_type(p, type) != pid) | |
1da177e4 LT |
1173 | return 0; |
1174 | } | |
1175 | ||
1176 | /* | |
1177 | * Do not consider detached threads that are | |
1178 | * not ptraced: | |
1179 | */ | |
d839fd4d | 1180 | if (task_detached(p) && !p->ptrace) |
1da177e4 LT |
1181 | return 0; |
1182 | ||
1183 | /* Wait for all children (clone and not) if __WALL is set; | |
1184 | * otherwise, wait for clone children *only* if __WCLONE is | |
1185 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1186 | * A "clone" child here is one that reports to its parent | |
1187 | * using a signal other than SIGCHLD.) */ | |
1188 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1189 | && !(options & __WALL)) | |
1190 | return 0; | |
1da177e4 | 1191 | |
73243284 | 1192 | err = security_task_wait(p); |
f2cc3eb1 ON |
1193 | if (likely(!err)) |
1194 | return 1; | |
1da177e4 | 1195 | |
161550d7 | 1196 | if (type != PIDTYPE_PID) |
f2cc3eb1 ON |
1197 | return 0; |
1198 | /* This child was explicitly requested, abort */ | |
1199 | read_unlock(&tasklist_lock); | |
1200 | return err; | |
1da177e4 LT |
1201 | } |
1202 | ||
36c8b586 | 1203 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1204 | int why, int status, |
1205 | struct siginfo __user *infop, | |
1206 | struct rusage __user *rusagep) | |
1207 | { | |
1208 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1209 | |
1da177e4 LT |
1210 | put_task_struct(p); |
1211 | if (!retval) | |
1212 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1213 | if (!retval) | |
1214 | retval = put_user(0, &infop->si_errno); | |
1215 | if (!retval) | |
1216 | retval = put_user((short)why, &infop->si_code); | |
1217 | if (!retval) | |
1218 | retval = put_user(pid, &infop->si_pid); | |
1219 | if (!retval) | |
1220 | retval = put_user(uid, &infop->si_uid); | |
1221 | if (!retval) | |
1222 | retval = put_user(status, &infop->si_status); | |
1223 | if (!retval) | |
1224 | retval = pid; | |
1225 | return retval; | |
1226 | } | |
1227 | ||
1228 | /* | |
1229 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1230 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1231 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1232 | * released the lock and the system call should return. | |
1233 | */ | |
36c8b586 | 1234 | static int wait_task_zombie(struct task_struct *p, int noreap, |
1da177e4 LT |
1235 | struct siginfo __user *infop, |
1236 | int __user *stat_addr, struct rusage __user *ru) | |
1237 | { | |
1238 | unsigned long state; | |
2f4e6e2a | 1239 | int retval, status, traced; |
6c5f3e7b | 1240 | pid_t pid = task_pid_vnr(p); |
1da177e4 LT |
1241 | |
1242 | if (unlikely(noreap)) { | |
1da177e4 LT |
1243 | uid_t uid = p->uid; |
1244 | int exit_code = p->exit_code; | |
1245 | int why, status; | |
1246 | ||
1da177e4 LT |
1247 | get_task_struct(p); |
1248 | read_unlock(&tasklist_lock); | |
1249 | if ((exit_code & 0x7f) == 0) { | |
1250 | why = CLD_EXITED; | |
1251 | status = exit_code >> 8; | |
1252 | } else { | |
1253 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1254 | status = exit_code & 0x7f; | |
1255 | } | |
1256 | return wait_noreap_copyout(p, pid, uid, why, | |
1257 | status, infop, ru); | |
1258 | } | |
1259 | ||
1260 | /* | |
1261 | * Try to move the task's state to DEAD | |
1262 | * only one thread is allowed to do this: | |
1263 | */ | |
1264 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1265 | if (state != EXIT_ZOMBIE) { | |
1266 | BUG_ON(state != EXIT_DEAD); | |
1267 | return 0; | |
1268 | } | |
1da177e4 | 1269 | |
53b6f9fb | 1270 | traced = ptrace_reparented(p); |
2f4e6e2a ON |
1271 | |
1272 | if (likely(!traced)) { | |
3795e161 JJ |
1273 | struct signal_struct *psig; |
1274 | struct signal_struct *sig; | |
1275 | ||
1da177e4 LT |
1276 | /* |
1277 | * The resource counters for the group leader are in its | |
1278 | * own task_struct. Those for dead threads in the group | |
1279 | * are in its signal_struct, as are those for the child | |
1280 | * processes it has previously reaped. All these | |
1281 | * accumulate in the parent's signal_struct c* fields. | |
1282 | * | |
1283 | * We don't bother to take a lock here to protect these | |
1284 | * p->signal fields, because they are only touched by | |
1285 | * __exit_signal, which runs with tasklist_lock | |
1286 | * write-locked anyway, and so is excluded here. We do | |
1287 | * need to protect the access to p->parent->signal fields, | |
1288 | * as other threads in the parent group can be right | |
1289 | * here reaping other children at the same time. | |
1290 | */ | |
1291 | spin_lock_irq(&p->parent->sighand->siglock); | |
3795e161 JJ |
1292 | psig = p->parent->signal; |
1293 | sig = p->signal; | |
1294 | psig->cutime = | |
1295 | cputime_add(psig->cutime, | |
1da177e4 | 1296 | cputime_add(p->utime, |
3795e161 JJ |
1297 | cputime_add(sig->utime, |
1298 | sig->cutime))); | |
1299 | psig->cstime = | |
1300 | cputime_add(psig->cstime, | |
1da177e4 | 1301 | cputime_add(p->stime, |
3795e161 JJ |
1302 | cputime_add(sig->stime, |
1303 | sig->cstime))); | |
9ac52315 LV |
1304 | psig->cgtime = |
1305 | cputime_add(psig->cgtime, | |
1306 | cputime_add(p->gtime, | |
1307 | cputime_add(sig->gtime, | |
1308 | sig->cgtime))); | |
3795e161 JJ |
1309 | psig->cmin_flt += |
1310 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1311 | psig->cmaj_flt += | |
1312 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1313 | psig->cnvcsw += | |
1314 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1315 | psig->cnivcsw += | |
1316 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1317 | psig->cinblock += |
1318 | task_io_get_inblock(p) + | |
1319 | sig->inblock + sig->cinblock; | |
1320 | psig->coublock += | |
1321 | task_io_get_oublock(p) + | |
1322 | sig->oublock + sig->coublock; | |
1da177e4 LT |
1323 | spin_unlock_irq(&p->parent->sighand->siglock); |
1324 | } | |
1325 | ||
1326 | /* | |
1327 | * Now we are sure this task is interesting, and no other | |
1328 | * thread can reap it because we set its state to EXIT_DEAD. | |
1329 | */ | |
1330 | read_unlock(&tasklist_lock); | |
1331 | ||
1332 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1333 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1334 | ? p->signal->group_exit_code : p->exit_code; | |
1335 | if (!retval && stat_addr) | |
1336 | retval = put_user(status, stat_addr); | |
1337 | if (!retval && infop) | |
1338 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1339 | if (!retval && infop) | |
1340 | retval = put_user(0, &infop->si_errno); | |
1341 | if (!retval && infop) { | |
1342 | int why; | |
1343 | ||
1344 | if ((status & 0x7f) == 0) { | |
1345 | why = CLD_EXITED; | |
1346 | status >>= 8; | |
1347 | } else { | |
1348 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1349 | status &= 0x7f; | |
1350 | } | |
1351 | retval = put_user((short)why, &infop->si_code); | |
1352 | if (!retval) | |
1353 | retval = put_user(status, &infop->si_status); | |
1354 | } | |
1355 | if (!retval && infop) | |
3a515e4a | 1356 | retval = put_user(pid, &infop->si_pid); |
1da177e4 LT |
1357 | if (!retval && infop) |
1358 | retval = put_user(p->uid, &infop->si_uid); | |
2f4e6e2a | 1359 | if (!retval) |
3a515e4a | 1360 | retval = pid; |
2f4e6e2a ON |
1361 | |
1362 | if (traced) { | |
1da177e4 | 1363 | write_lock_irq(&tasklist_lock); |
2f4e6e2a ON |
1364 | /* We dropped tasklist, ptracer could die and untrace */ |
1365 | ptrace_unlink(p); | |
1366 | /* | |
1367 | * If this is not a detached task, notify the parent. | |
1368 | * If it's still not detached after that, don't release | |
1369 | * it now. | |
1370 | */ | |
d839fd4d | 1371 | if (!task_detached(p)) { |
2f4e6e2a | 1372 | do_notify_parent(p, p->exit_signal); |
d839fd4d | 1373 | if (!task_detached(p)) { |
2f4e6e2a ON |
1374 | p->exit_state = EXIT_ZOMBIE; |
1375 | p = NULL; | |
1da177e4 LT |
1376 | } |
1377 | } | |
1378 | write_unlock_irq(&tasklist_lock); | |
1379 | } | |
1380 | if (p != NULL) | |
1381 | release_task(p); | |
2f4e6e2a | 1382 | |
1da177e4 LT |
1383 | return retval; |
1384 | } | |
1385 | ||
1386 | /* | |
1387 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1388 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1389 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1390 | * released the lock and the system call should return. | |
1391 | */ | |
1bad95c3 | 1392 | static int wait_task_stopped(struct task_struct *p, |
36c8b586 | 1393 | int noreap, struct siginfo __user *infop, |
1da177e4 LT |
1394 | int __user *stat_addr, struct rusage __user *ru) |
1395 | { | |
ee7c82da ON |
1396 | int retval, exit_code, why; |
1397 | uid_t uid = 0; /* unneeded, required by compiler */ | |
c8950783 | 1398 | pid_t pid; |
1da177e4 | 1399 | |
ee7c82da ON |
1400 | exit_code = 0; |
1401 | spin_lock_irq(&p->sighand->siglock); | |
1402 | ||
1403 | if (unlikely(!task_is_stopped_or_traced(p))) | |
1404 | goto unlock_sig; | |
1405 | ||
1bad95c3 | 1406 | if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0) |
1da177e4 LT |
1407 | /* |
1408 | * A group stop is in progress and this is the group leader. | |
1409 | * We won't report until all threads have stopped. | |
1410 | */ | |
ee7c82da ON |
1411 | goto unlock_sig; |
1412 | ||
1413 | exit_code = p->exit_code; | |
1414 | if (!exit_code) | |
1415 | goto unlock_sig; | |
1416 | ||
1417 | if (!noreap) | |
1418 | p->exit_code = 0; | |
1419 | ||
1420 | uid = p->uid; | |
1421 | unlock_sig: | |
1422 | spin_unlock_irq(&p->sighand->siglock); | |
1423 | if (!exit_code) | |
1da177e4 LT |
1424 | return 0; |
1425 | ||
1426 | /* | |
1427 | * Now we are pretty sure this task is interesting. | |
1428 | * Make sure it doesn't get reaped out from under us while we | |
1429 | * give up the lock and then examine it below. We don't want to | |
1430 | * keep holding onto the tasklist_lock while we call getrusage and | |
1431 | * possibly take page faults for user memory. | |
1432 | */ | |
1433 | get_task_struct(p); | |
6c5f3e7b | 1434 | pid = task_pid_vnr(p); |
ee7c82da | 1435 | why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; |
1da177e4 LT |
1436 | read_unlock(&tasklist_lock); |
1437 | ||
ee7c82da | 1438 | if (unlikely(noreap)) |
1da177e4 | 1439 | return wait_noreap_copyout(p, pid, uid, |
e6ceb32a | 1440 | why, exit_code, |
1da177e4 | 1441 | infop, ru); |
1da177e4 LT |
1442 | |
1443 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1444 | if (!retval && stat_addr) | |
1445 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1446 | if (!retval && infop) | |
1447 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1448 | if (!retval && infop) | |
1449 | retval = put_user(0, &infop->si_errno); | |
1450 | if (!retval && infop) | |
6efcae46 | 1451 | retval = put_user((short)why, &infop->si_code); |
1da177e4 LT |
1452 | if (!retval && infop) |
1453 | retval = put_user(exit_code, &infop->si_status); | |
1454 | if (!retval && infop) | |
c8950783 | 1455 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1456 | if (!retval && infop) |
ee7c82da | 1457 | retval = put_user(uid, &infop->si_uid); |
1da177e4 | 1458 | if (!retval) |
c8950783 | 1459 | retval = pid; |
1da177e4 LT |
1460 | put_task_struct(p); |
1461 | ||
1462 | BUG_ON(!retval); | |
1463 | return retval; | |
1464 | } | |
1465 | ||
1466 | /* | |
1467 | * Handle do_wait work for one task in a live, non-stopped state. | |
1468 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1469 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1470 | * released the lock and the system call should return. | |
1471 | */ | |
36c8b586 | 1472 | static int wait_task_continued(struct task_struct *p, int noreap, |
1da177e4 LT |
1473 | struct siginfo __user *infop, |
1474 | int __user *stat_addr, struct rusage __user *ru) | |
1475 | { | |
1476 | int retval; | |
1477 | pid_t pid; | |
1478 | uid_t uid; | |
1479 | ||
1da177e4 LT |
1480 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
1481 | return 0; | |
1482 | ||
1483 | spin_lock_irq(&p->sighand->siglock); | |
1484 | /* Re-check with the lock held. */ | |
1485 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1486 | spin_unlock_irq(&p->sighand->siglock); | |
1487 | return 0; | |
1488 | } | |
1489 | if (!noreap) | |
1490 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; | |
1491 | spin_unlock_irq(&p->sighand->siglock); | |
1492 | ||
6c5f3e7b | 1493 | pid = task_pid_vnr(p); |
1da177e4 LT |
1494 | uid = p->uid; |
1495 | get_task_struct(p); | |
1496 | read_unlock(&tasklist_lock); | |
1497 | ||
1498 | if (!infop) { | |
1499 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1500 | put_task_struct(p); | |
1501 | if (!retval && stat_addr) | |
1502 | retval = put_user(0xffff, stat_addr); | |
1503 | if (!retval) | |
3a515e4a | 1504 | retval = pid; |
1da177e4 LT |
1505 | } else { |
1506 | retval = wait_noreap_copyout(p, pid, uid, | |
1507 | CLD_CONTINUED, SIGCONT, | |
1508 | infop, ru); | |
1509 | BUG_ON(retval == 0); | |
1510 | } | |
1511 | ||
1512 | return retval; | |
1513 | } | |
1514 | ||
161550d7 EB |
1515 | static long do_wait(enum pid_type type, struct pid *pid, int options, |
1516 | struct siginfo __user *infop, int __user *stat_addr, | |
1517 | struct rusage __user *ru) | |
1da177e4 LT |
1518 | { |
1519 | DECLARE_WAITQUEUE(wait, current); | |
1520 | struct task_struct *tsk; | |
1521 | int flag, retval; | |
1522 | ||
1523 | add_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1524 | repeat: | |
161550d7 EB |
1525 | /* If there is nothing that can match our critier just get out */ |
1526 | retval = -ECHILD; | |
1527 | if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) | |
1528 | goto end; | |
1529 | ||
1da177e4 LT |
1530 | /* |
1531 | * We will set this flag if we see any child that might later | |
1532 | * match our criteria, even if we are not able to reap it yet. | |
1533 | */ | |
f2cc3eb1 | 1534 | flag = retval = 0; |
1da177e4 LT |
1535 | current->state = TASK_INTERRUPTIBLE; |
1536 | read_lock(&tasklist_lock); | |
1537 | tsk = current; | |
1538 | do { | |
1539 | struct task_struct *p; | |
1da177e4 | 1540 | |
03ff1797 | 1541 | list_for_each_entry(p, &tsk->children, sibling) { |
161550d7 | 1542 | int ret = eligible_child(type, pid, options, p); |
1da177e4 LT |
1543 | if (!ret) |
1544 | continue; | |
1545 | ||
73243284 | 1546 | if (unlikely(ret < 0)) { |
f2cc3eb1 ON |
1547 | retval = ret; |
1548 | } else if (task_is_stopped_or_traced(p)) { | |
1da177e4 LT |
1549 | /* |
1550 | * It's stopped now, so it might later | |
1551 | * continue, exit, or stop again. | |
1552 | */ | |
1553 | flag = 1; | |
34a1738f ON |
1554 | if (!(p->ptrace & PT_PTRACED) && |
1555 | !(options & WUNTRACED)) | |
1556 | continue; | |
338077e5 | 1557 | |
1bad95c3 | 1558 | retval = wait_task_stopped(p, |
338077e5 MW |
1559 | (options & WNOWAIT), infop, |
1560 | stat_addr, ru); | |
96fabbf5 ON |
1561 | } else if (p->exit_state == EXIT_ZOMBIE && |
1562 | !delay_group_leader(p)) { | |
338077e5 | 1563 | /* |
96fabbf5 | 1564 | * We don't reap group leaders with subthreads. |
338077e5 | 1565 | */ |
338077e5 | 1566 | if (!likely(options & WEXITED)) |
1da177e4 | 1567 | continue; |
338077e5 MW |
1568 | retval = wait_task_zombie(p, |
1569 | (options & WNOWAIT), infop, | |
1570 | stat_addr, ru); | |
0a76fe8e | 1571 | } else if (p->exit_state != EXIT_DEAD) { |
1da177e4 LT |
1572 | /* |
1573 | * It's running now, so it might later | |
1574 | * exit, stop, or stop and then continue. | |
1575 | */ | |
1576 | flag = 1; | |
1577 | if (!unlikely(options & WCONTINUED)) | |
1578 | continue; | |
338077e5 MW |
1579 | retval = wait_task_continued(p, |
1580 | (options & WNOWAIT), infop, | |
1581 | stat_addr, ru); | |
1da177e4 | 1582 | } |
9cbab810 ON |
1583 | if (retval != 0) /* tasklist_lock released */ |
1584 | goto end; | |
1da177e4 LT |
1585 | } |
1586 | if (!flag) { | |
03ff1797 | 1587 | list_for_each_entry(p, &tsk->ptrace_children, |
f2cc3eb1 | 1588 | ptrace_list) { |
161550d7 | 1589 | flag = eligible_child(type, pid, options, p); |
f2cc3eb1 | 1590 | if (!flag) |
1da177e4 | 1591 | continue; |
f2cc3eb1 ON |
1592 | if (likely(flag > 0)) |
1593 | break; | |
1594 | retval = flag; | |
1595 | goto end; | |
1da177e4 LT |
1596 | } |
1597 | } | |
1598 | if (options & __WNOTHREAD) | |
1599 | break; | |
1600 | tsk = next_thread(tsk); | |
125e1874 | 1601 | BUG_ON(tsk->signal != current->signal); |
1da177e4 | 1602 | } while (tsk != current); |
1da177e4 | 1603 | read_unlock(&tasklist_lock); |
f2cc3eb1 | 1604 | |
1da177e4 | 1605 | if (flag) { |
1da177e4 LT |
1606 | if (options & WNOHANG) |
1607 | goto end; | |
1608 | retval = -ERESTARTSYS; | |
1609 | if (signal_pending(current)) | |
1610 | goto end; | |
1611 | schedule(); | |
1612 | goto repeat; | |
1613 | } | |
1614 | retval = -ECHILD; | |
1615 | end: | |
1616 | current->state = TASK_RUNNING; | |
1617 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1618 | if (infop) { | |
1619 | if (retval > 0) | |
9cbab810 | 1620 | retval = 0; |
1da177e4 LT |
1621 | else { |
1622 | /* | |
1623 | * For a WNOHANG return, clear out all the fields | |
1624 | * we would set so the user can easily tell the | |
1625 | * difference. | |
1626 | */ | |
1627 | if (!retval) | |
1628 | retval = put_user(0, &infop->si_signo); | |
1629 | if (!retval) | |
1630 | retval = put_user(0, &infop->si_errno); | |
1631 | if (!retval) | |
1632 | retval = put_user(0, &infop->si_code); | |
1633 | if (!retval) | |
1634 | retval = put_user(0, &infop->si_pid); | |
1635 | if (!retval) | |
1636 | retval = put_user(0, &infop->si_uid); | |
1637 | if (!retval) | |
1638 | retval = put_user(0, &infop->si_status); | |
1639 | } | |
1640 | } | |
1641 | return retval; | |
1642 | } | |
1643 | ||
161550d7 | 1644 | asmlinkage long sys_waitid(int which, pid_t upid, |
1da177e4 LT |
1645 | struct siginfo __user *infop, int options, |
1646 | struct rusage __user *ru) | |
1647 | { | |
161550d7 EB |
1648 | struct pid *pid = NULL; |
1649 | enum pid_type type; | |
1da177e4 LT |
1650 | long ret; |
1651 | ||
1652 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1653 | return -EINVAL; | |
1654 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1655 | return -EINVAL; | |
1656 | ||
1657 | switch (which) { | |
1658 | case P_ALL: | |
161550d7 | 1659 | type = PIDTYPE_MAX; |
1da177e4 LT |
1660 | break; |
1661 | case P_PID: | |
161550d7 EB |
1662 | type = PIDTYPE_PID; |
1663 | if (upid <= 0) | |
1da177e4 LT |
1664 | return -EINVAL; |
1665 | break; | |
1666 | case P_PGID: | |
161550d7 EB |
1667 | type = PIDTYPE_PGID; |
1668 | if (upid <= 0) | |
1da177e4 | 1669 | return -EINVAL; |
1da177e4 LT |
1670 | break; |
1671 | default: | |
1672 | return -EINVAL; | |
1673 | } | |
1674 | ||
161550d7 EB |
1675 | if (type < PIDTYPE_MAX) |
1676 | pid = find_get_pid(upid); | |
1677 | ret = do_wait(type, pid, options, infop, NULL, ru); | |
1678 | put_pid(pid); | |
1da177e4 LT |
1679 | |
1680 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1681 | asmlinkage_protect(5, ret, which, upid, infop, options, ru); |
1da177e4 LT |
1682 | return ret; |
1683 | } | |
1684 | ||
161550d7 | 1685 | asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr, |
1da177e4 LT |
1686 | int options, struct rusage __user *ru) |
1687 | { | |
161550d7 EB |
1688 | struct pid *pid = NULL; |
1689 | enum pid_type type; | |
1da177e4 LT |
1690 | long ret; |
1691 | ||
1692 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1693 | __WNOTHREAD|__WCLONE|__WALL)) | |
1694 | return -EINVAL; | |
161550d7 EB |
1695 | |
1696 | if (upid == -1) | |
1697 | type = PIDTYPE_MAX; | |
1698 | else if (upid < 0) { | |
1699 | type = PIDTYPE_PGID; | |
1700 | pid = find_get_pid(-upid); | |
1701 | } else if (upid == 0) { | |
1702 | type = PIDTYPE_PGID; | |
1703 | pid = get_pid(task_pgrp(current)); | |
1704 | } else /* upid > 0 */ { | |
1705 | type = PIDTYPE_PID; | |
1706 | pid = find_get_pid(upid); | |
1707 | } | |
1708 | ||
1709 | ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru); | |
1710 | put_pid(pid); | |
1da177e4 LT |
1711 | |
1712 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1713 | asmlinkage_protect(4, ret, upid, stat_addr, options, ru); |
1da177e4 LT |
1714 | return ret; |
1715 | } | |
1716 | ||
1717 | #ifdef __ARCH_WANT_SYS_WAITPID | |
1718 | ||
1719 | /* | |
1720 | * sys_waitpid() remains for compatibility. waitpid() should be | |
1721 | * implemented by calling sys_wait4() from libc.a. | |
1722 | */ | |
1723 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) | |
1724 | { | |
1725 | return sys_wait4(pid, stat_addr, options, NULL); | |
1726 | } | |
1727 | ||
1728 | #endif |