Commit | Line | Data |
---|---|---|
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> |
da9cbc87 | 16 | #include <linux/iocontext.h> |
1da177e4 LT |
17 | #include <linux/key.h> |
18 | #include <linux/security.h> | |
19 | #include <linux/cpu.h> | |
20 | #include <linux/acct.h> | |
8f0ab514 | 21 | #include <linux/tsacct_kern.h> |
1da177e4 | 22 | #include <linux/file.h> |
9f3acc31 | 23 | #include <linux/fdtable.h> |
1da177e4 | 24 | #include <linux/binfmts.h> |
ab516013 | 25 | #include <linux/nsproxy.h> |
84d73786 | 26 | #include <linux/pid_namespace.h> |
1da177e4 LT |
27 | #include <linux/ptrace.h> |
28 | #include <linux/profile.h> | |
29 | #include <linux/mount.h> | |
30 | #include <linux/proc_fs.h> | |
49d769d5 | 31 | #include <linux/kthread.h> |
1da177e4 | 32 | #include <linux/mempolicy.h> |
c757249a | 33 | #include <linux/taskstats_kern.h> |
ca74e92b | 34 | #include <linux/delayacct.h> |
83144186 | 35 | #include <linux/freezer.h> |
b4f48b63 | 36 | #include <linux/cgroup.h> |
1da177e4 | 37 | #include <linux/syscalls.h> |
7ed20e1a | 38 | #include <linux/signal.h> |
6a14c5c9 | 39 | #include <linux/posix-timers.h> |
9f46080c | 40 | #include <linux/cn_proc.h> |
de5097c2 | 41 | #include <linux/mutex.h> |
0771dfef | 42 | #include <linux/futex.h> |
34f192c6 | 43 | #include <linux/compat.h> |
b92ce558 | 44 | #include <linux/pipe_fs_i.h> |
fa84cb93 | 45 | #include <linux/audit.h> /* for audit_free() */ |
83cc5ed3 | 46 | #include <linux/resource.h> |
0d67a46d | 47 | #include <linux/blkdev.h> |
6eaeeaba | 48 | #include <linux/task_io_accounting_ops.h> |
30199f5a | 49 | #include <linux/tracehook.h> |
0a16b607 | 50 | #include <trace/sched.h> |
1da177e4 LT |
51 | |
52 | #include <asm/uaccess.h> | |
53 | #include <asm/unistd.h> | |
54 | #include <asm/pgtable.h> | |
55 | #include <asm/mmu_context.h> | |
56 | ||
408b664a AB |
57 | static void exit_mm(struct task_struct * tsk); |
58 | ||
d839fd4d ON |
59 | static inline int task_detached(struct task_struct *p) |
60 | { | |
61 | return p->exit_signal == -1; | |
62 | } | |
63 | ||
1da177e4 LT |
64 | static void __unhash_process(struct task_struct *p) |
65 | { | |
66 | nr_threads--; | |
67 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
68 | if (thread_group_leader(p)) { |
69 | detach_pid(p, PIDTYPE_PGID); | |
70 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 71 | |
5e85d4ab | 72 | list_del_rcu(&p->tasks); |
73b9ebfe | 73 | __get_cpu_var(process_counts)--; |
1da177e4 | 74 | } |
47e65328 | 75 | list_del_rcu(&p->thread_group); |
f470021a | 76 | list_del_init(&p->sibling); |
1da177e4 LT |
77 | } |
78 | ||
6a14c5c9 ON |
79 | /* |
80 | * This function expects the tasklist_lock write-locked. | |
81 | */ | |
82 | static void __exit_signal(struct task_struct *tsk) | |
83 | { | |
84 | struct signal_struct *sig = tsk->signal; | |
85 | struct sighand_struct *sighand; | |
86 | ||
87 | BUG_ON(!sig); | |
88 | BUG_ON(!atomic_read(&sig->count)); | |
89 | ||
6a14c5c9 ON |
90 | sighand = rcu_dereference(tsk->sighand); |
91 | spin_lock(&sighand->siglock); | |
92 | ||
93 | posix_cpu_timers_exit(tsk); | |
94 | if (atomic_dec_and_test(&sig->count)) | |
95 | posix_cpu_timers_exit_group(tsk); | |
96 | else { | |
97 | /* | |
98 | * If there is any task waiting for the group exit | |
99 | * then notify it: | |
100 | */ | |
6db840fa | 101 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) |
6a14c5c9 | 102 | wake_up_process(sig->group_exit_task); |
6db840fa | 103 | |
6a14c5c9 ON |
104 | if (tsk == sig->curr_target) |
105 | sig->curr_target = next_thread(tsk); | |
106 | /* | |
107 | * Accumulate here the counters for all threads but the | |
108 | * group leader as they die, so they can be added into | |
109 | * the process-wide totals when those are taken. | |
110 | * The group leader stays around as a zombie as long | |
111 | * as there are other threads. When it gets reaped, | |
112 | * the exit.c code will add its counts into these totals. | |
113 | * We won't ever get here for the group leader, since it | |
114 | * will have been the last reference on the signal_struct. | |
115 | */ | |
49048622 | 116 | sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); |
6a14c5c9 ON |
117 | sig->min_flt += tsk->min_flt; |
118 | sig->maj_flt += tsk->maj_flt; | |
119 | sig->nvcsw += tsk->nvcsw; | |
120 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
121 | sig->inblock += task_io_get_inblock(tsk); |
122 | sig->oublock += task_io_get_oublock(tsk); | |
5995477a | 123 | task_io_accounting_add(&sig->ioac, &tsk->ioac); |
6a14c5c9 ON |
124 | sig = NULL; /* Marker for below. */ |
125 | } | |
126 | ||
5876700c ON |
127 | __unhash_process(tsk); |
128 | ||
da7978b0 ON |
129 | /* |
130 | * Do this under ->siglock, we can race with another thread | |
131 | * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals. | |
132 | */ | |
133 | flush_sigqueue(&tsk->pending); | |
134 | ||
6a14c5c9 | 135 | tsk->signal = NULL; |
a7e5328a | 136 | tsk->sighand = NULL; |
6a14c5c9 | 137 | spin_unlock(&sighand->siglock); |
6a14c5c9 | 138 | |
a7e5328a | 139 | __cleanup_sighand(sighand); |
6a14c5c9 | 140 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
6a14c5c9 ON |
141 | if (sig) { |
142 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 143 | taskstats_tgid_free(sig); |
6a14c5c9 ON |
144 | __cleanup_signal(sig); |
145 | } | |
146 | } | |
147 | ||
8c7904a0 EB |
148 | static void delayed_put_task_struct(struct rcu_head *rhp) |
149 | { | |
0a16b607 MD |
150 | struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); |
151 | ||
152 | trace_sched_process_free(tsk); | |
153 | put_task_struct(tsk); | |
8c7904a0 EB |
154 | } |
155 | ||
f470021a | 156 | |
1da177e4 LT |
157 | void release_task(struct task_struct * p) |
158 | { | |
36c8b586 | 159 | struct task_struct *leader; |
1da177e4 | 160 | int zap_leader; |
1f09f974 | 161 | repeat: |
dae33574 | 162 | tracehook_prepare_release_task(p); |
c69e8d9c DH |
163 | /* don't need to get the RCU readlock here - the process is dead and |
164 | * can't be modifying its own credentials */ | |
165 | atomic_dec(&__task_cred(p)->user->processes); | |
166 | ||
60347f67 | 167 | proc_flush_task(p); |
1da177e4 | 168 | write_lock_irq(&tasklist_lock); |
dae33574 | 169 | tracehook_finish_release_task(p); |
1da177e4 | 170 | __exit_signal(p); |
35f5cad8 | 171 | |
1da177e4 LT |
172 | /* |
173 | * If we are the last non-leader member of the thread | |
174 | * group, and the leader is zombie, then notify the | |
175 | * group leader's parent process. (if it wants notification.) | |
176 | */ | |
177 | zap_leader = 0; | |
178 | leader = p->group_leader; | |
179 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
d839fd4d | 180 | BUG_ON(task_detached(leader)); |
1da177e4 LT |
181 | do_notify_parent(leader, leader->exit_signal); |
182 | /* | |
183 | * If we were the last child thread and the leader has | |
184 | * exited already, and the leader's parent ignores SIGCHLD, | |
185 | * then we are the one who should release the leader. | |
186 | * | |
187 | * do_notify_parent() will have marked it self-reaping in | |
188 | * that case. | |
189 | */ | |
d839fd4d | 190 | zap_leader = task_detached(leader); |
dae33574 RM |
191 | |
192 | /* | |
193 | * This maintains the invariant that release_task() | |
194 | * only runs on a task in EXIT_DEAD, just for sanity. | |
195 | */ | |
196 | if (zap_leader) | |
197 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
198 | } |
199 | ||
1da177e4 | 200 | write_unlock_irq(&tasklist_lock); |
1da177e4 | 201 | release_thread(p); |
8c7904a0 | 202 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
203 | |
204 | p = leader; | |
205 | if (unlikely(zap_leader)) | |
206 | goto repeat; | |
207 | } | |
208 | ||
1da177e4 LT |
209 | /* |
210 | * This checks not only the pgrp, but falls back on the pid if no | |
211 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
212 | * without this... | |
04a2e6a5 EB |
213 | * |
214 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 215 | */ |
04a2e6a5 | 216 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
217 | { |
218 | struct task_struct *p; | |
04a2e6a5 | 219 | struct pid *sid = NULL; |
62dfb554 | 220 | |
04a2e6a5 | 221 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 222 | if (p == NULL) |
04a2e6a5 | 223 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 224 | if (p != NULL) |
04a2e6a5 | 225 | sid = task_session(p); |
62dfb554 | 226 | |
1da177e4 LT |
227 | return sid; |
228 | } | |
229 | ||
230 | /* | |
231 | * Determine if a process group is "orphaned", according to the POSIX | |
232 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
233 | * by terminal-generated stop signals. Newly orphaned process groups are | |
234 | * to receive a SIGHUP and a SIGCONT. | |
235 | * | |
236 | * "I ask you, have you ever known what it is to be an orphan?" | |
237 | */ | |
0475ac08 | 238 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
239 | { |
240 | struct task_struct *p; | |
1da177e4 | 241 | |
0475ac08 | 242 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
05e83df6 ON |
243 | if ((p == ignored_task) || |
244 | (p->exit_state && thread_group_empty(p)) || | |
245 | is_global_init(p->real_parent)) | |
1da177e4 | 246 | continue; |
05e83df6 | 247 | |
0475ac08 | 248 | if (task_pgrp(p->real_parent) != pgrp && |
05e83df6 ON |
249 | task_session(p->real_parent) == task_session(p)) |
250 | return 0; | |
0475ac08 | 251 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
05e83df6 ON |
252 | |
253 | return 1; | |
1da177e4 LT |
254 | } |
255 | ||
3e7cd6c4 | 256 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
257 | { |
258 | int retval; | |
259 | ||
260 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 261 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
262 | read_unlock(&tasklist_lock); |
263 | ||
264 | return retval; | |
265 | } | |
266 | ||
0475ac08 | 267 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
268 | { |
269 | int retval = 0; | |
270 | struct task_struct *p; | |
271 | ||
0475ac08 | 272 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
338077e5 | 273 | if (!task_is_stopped(p)) |
1da177e4 | 274 | continue; |
1da177e4 LT |
275 | retval = 1; |
276 | break; | |
0475ac08 | 277 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
278 | return retval; |
279 | } | |
280 | ||
f49ee505 ON |
281 | /* |
282 | * Check to see if any process groups have become orphaned as | |
283 | * a result of our exiting, and if they have any stopped jobs, | |
284 | * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
285 | */ | |
286 | static void | |
287 | kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) | |
288 | { | |
289 | struct pid *pgrp = task_pgrp(tsk); | |
290 | struct task_struct *ignored_task = tsk; | |
291 | ||
292 | if (!parent) | |
293 | /* exit: our father is in a different pgrp than | |
294 | * we are and we were the only connection outside. | |
295 | */ | |
296 | parent = tsk->real_parent; | |
297 | else | |
298 | /* reparent: our child is in a different pgrp than | |
299 | * we are, and it was the only connection outside. | |
300 | */ | |
301 | ignored_task = NULL; | |
302 | ||
303 | if (task_pgrp(parent) != pgrp && | |
304 | task_session(parent) == task_session(tsk) && | |
305 | will_become_orphaned_pgrp(pgrp, ignored_task) && | |
306 | has_stopped_jobs(pgrp)) { | |
307 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
308 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
309 | } | |
310 | } | |
311 | ||
1da177e4 | 312 | /** |
49d769d5 | 313 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
314 | * |
315 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
316 | * it ever exits, it should generally reparent itself to kthreadd so it |
317 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
318 | * |
319 | * The various task state such as scheduling policy and priority may have | |
320 | * been inherited from a user process, so we reset them to sane values here. | |
321 | * | |
49d769d5 | 322 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 323 | */ |
49d769d5 | 324 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
325 | { |
326 | write_lock_irq(&tasklist_lock); | |
327 | ||
328 | ptrace_unlink(current); | |
329 | /* Reparent to init */ | |
49d769d5 | 330 | current->real_parent = current->parent = kthreadd_task; |
f470021a | 331 | list_move_tail(¤t->sibling, ¤t->real_parent->children); |
1da177e4 LT |
332 | |
333 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
334 | current->exit_signal = SIGCHLD; | |
335 | ||
e05606d3 | 336 | if (task_nice(current) < 0) |
1da177e4 LT |
337 | set_user_nice(current, 0); |
338 | /* cpus_allowed? */ | |
339 | /* rt_priority? */ | |
340 | /* signals? */ | |
341 | security_task_reparent_to_init(current); | |
342 | memcpy(current->signal->rlim, init_task.signal->rlim, | |
343 | sizeof(current->signal->rlim)); | |
344 | atomic_inc(&(INIT_USER->__count)); | |
345 | write_unlock_irq(&tasklist_lock); | |
346 | switch_uid(INIT_USER); | |
347 | } | |
348 | ||
8520d7c7 | 349 | void __set_special_pids(struct pid *pid) |
1da177e4 | 350 | { |
e19f247a | 351 | struct task_struct *curr = current->group_leader; |
8520d7c7 | 352 | pid_t nr = pid_nr(pid); |
1da177e4 | 353 | |
8520d7c7 | 354 | if (task_session(curr) != pid) { |
7d8da096 | 355 | change_pid(curr, PIDTYPE_SID, pid); |
8520d7c7 | 356 | set_task_session(curr, nr); |
1da177e4 | 357 | } |
8520d7c7 | 358 | if (task_pgrp(curr) != pid) { |
7d8da096 | 359 | change_pid(curr, PIDTYPE_PGID, pid); |
8520d7c7 | 360 | set_task_pgrp(curr, nr); |
1da177e4 LT |
361 | } |
362 | } | |
363 | ||
8520d7c7 | 364 | static void set_special_pids(struct pid *pid) |
1da177e4 LT |
365 | { |
366 | write_lock_irq(&tasklist_lock); | |
8520d7c7 | 367 | __set_special_pids(pid); |
1da177e4 LT |
368 | write_unlock_irq(&tasklist_lock); |
369 | } | |
370 | ||
371 | /* | |
372 | * Let kernel threads use this to say that they | |
373 | * allow a certain signal (since daemonize() will | |
374 | * have disabled all of them by default). | |
375 | */ | |
376 | int allow_signal(int sig) | |
377 | { | |
7ed20e1a | 378 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
379 | return -EINVAL; |
380 | ||
381 | spin_lock_irq(¤t->sighand->siglock); | |
382 | sigdelset(¤t->blocked, sig); | |
383 | if (!current->mm) { | |
384 | /* Kernel threads handle their own signals. | |
385 | Let the signal code know it'll be handled, so | |
386 | that they don't get converted to SIGKILL or | |
387 | just silently dropped */ | |
388 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
389 | } | |
390 | recalc_sigpending(); | |
391 | spin_unlock_irq(¤t->sighand->siglock); | |
392 | return 0; | |
393 | } | |
394 | ||
395 | EXPORT_SYMBOL(allow_signal); | |
396 | ||
397 | int disallow_signal(int sig) | |
398 | { | |
7ed20e1a | 399 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
400 | return -EINVAL; |
401 | ||
402 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 403 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
404 | recalc_sigpending(); |
405 | spin_unlock_irq(¤t->sighand->siglock); | |
406 | return 0; | |
407 | } | |
408 | ||
409 | EXPORT_SYMBOL(disallow_signal); | |
410 | ||
411 | /* | |
412 | * Put all the gunge required to become a kernel thread without | |
413 | * attached user resources in one place where it belongs. | |
414 | */ | |
415 | ||
416 | void daemonize(const char *name, ...) | |
417 | { | |
418 | va_list args; | |
419 | struct fs_struct *fs; | |
420 | sigset_t blocked; | |
421 | ||
422 | va_start(args, name); | |
423 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
424 | va_end(args); | |
425 | ||
426 | /* | |
427 | * If we were started as result of loading a module, close all of the | |
428 | * user space pages. We don't need them, and if we didn't close them | |
429 | * they would be locked into memory. | |
430 | */ | |
431 | exit_mm(current); | |
83144186 RW |
432 | /* |
433 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
434 | * or suspend transition begins right now. | |
435 | */ | |
7b34e428 | 436 | current->flags |= (PF_NOFREEZE | PF_KTHREAD); |
1da177e4 | 437 | |
8520d7c7 ON |
438 | if (current->nsproxy != &init_nsproxy) { |
439 | get_nsproxy(&init_nsproxy); | |
440 | switch_task_namespaces(current, &init_nsproxy); | |
441 | } | |
297bd42b | 442 | set_special_pids(&init_struct_pid); |
24ec839c | 443 | proc_clear_tty(current); |
1da177e4 LT |
444 | |
445 | /* Block and flush all signals */ | |
446 | sigfillset(&blocked); | |
447 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
448 | flush_signals(current); | |
449 | ||
450 | /* Become as one with the init task */ | |
451 | ||
452 | exit_fs(current); /* current->fs->count--; */ | |
453 | fs = init_task.fs; | |
454 | current->fs = fs; | |
455 | atomic_inc(&fs->count); | |
ab516013 | 456 | |
d4c5e41f | 457 | exit_files(current); |
1da177e4 LT |
458 | current->files = init_task.files; |
459 | atomic_inc(¤t->files->count); | |
460 | ||
49d769d5 | 461 | reparent_to_kthreadd(); |
1da177e4 LT |
462 | } |
463 | ||
464 | EXPORT_SYMBOL(daemonize); | |
465 | ||
858119e1 | 466 | static void close_files(struct files_struct * files) |
1da177e4 LT |
467 | { |
468 | int i, j; | |
badf1662 | 469 | struct fdtable *fdt; |
1da177e4 LT |
470 | |
471 | j = 0; | |
4fb3a538 DS |
472 | |
473 | /* | |
474 | * It is safe to dereference the fd table without RCU or | |
475 | * ->file_lock because this is the last reference to the | |
476 | * files structure. | |
477 | */ | |
badf1662 | 478 | fdt = files_fdtable(files); |
1da177e4 LT |
479 | for (;;) { |
480 | unsigned long set; | |
481 | i = j * __NFDBITS; | |
bbea9f69 | 482 | if (i >= fdt->max_fds) |
1da177e4 | 483 | break; |
badf1662 | 484 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
485 | while (set) { |
486 | if (set & 1) { | |
badf1662 | 487 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 488 | if (file) { |
1da177e4 | 489 | filp_close(file, files); |
944be0b2 IM |
490 | cond_resched(); |
491 | } | |
1da177e4 LT |
492 | } |
493 | i++; | |
494 | set >>= 1; | |
495 | } | |
496 | } | |
497 | } | |
498 | ||
499 | struct files_struct *get_files_struct(struct task_struct *task) | |
500 | { | |
501 | struct files_struct *files; | |
502 | ||
503 | task_lock(task); | |
504 | files = task->files; | |
505 | if (files) | |
506 | atomic_inc(&files->count); | |
507 | task_unlock(task); | |
508 | ||
509 | return files; | |
510 | } | |
511 | ||
7ad5b3a5 | 512 | void put_files_struct(struct files_struct *files) |
1da177e4 | 513 | { |
badf1662 DS |
514 | struct fdtable *fdt; |
515 | ||
1da177e4 LT |
516 | if (atomic_dec_and_test(&files->count)) { |
517 | close_files(files); | |
518 | /* | |
519 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
520 | * If the fdtable was embedded, pass files for freeing |
521 | * at the end of the RCU grace period. Otherwise, | |
522 | * you can free files immediately. | |
1da177e4 | 523 | */ |
badf1662 | 524 | fdt = files_fdtable(files); |
4fd45812 | 525 | if (fdt != &files->fdtab) |
ab2af1f5 | 526 | kmem_cache_free(files_cachep, files); |
01b2d93c | 527 | free_fdtable(fdt); |
1da177e4 LT |
528 | } |
529 | } | |
530 | ||
3b125388 | 531 | void reset_files_struct(struct files_struct *files) |
3b9b8ab6 | 532 | { |
3b125388 | 533 | struct task_struct *tsk = current; |
3b9b8ab6 KK |
534 | struct files_struct *old; |
535 | ||
536 | old = tsk->files; | |
537 | task_lock(tsk); | |
538 | tsk->files = files; | |
539 | task_unlock(tsk); | |
540 | put_files_struct(old); | |
541 | } | |
3b9b8ab6 | 542 | |
1ec7f1dd | 543 | void exit_files(struct task_struct *tsk) |
1da177e4 LT |
544 | { |
545 | struct files_struct * files = tsk->files; | |
546 | ||
547 | if (files) { | |
548 | task_lock(tsk); | |
549 | tsk->files = NULL; | |
550 | task_unlock(tsk); | |
551 | put_files_struct(files); | |
552 | } | |
553 | } | |
554 | ||
1ec7f1dd | 555 | void put_fs_struct(struct fs_struct *fs) |
1da177e4 LT |
556 | { |
557 | /* No need to hold fs->lock if we are killing it */ | |
558 | if (atomic_dec_and_test(&fs->count)) { | |
6ac08c39 JB |
559 | path_put(&fs->root); |
560 | path_put(&fs->pwd); | |
1da177e4 LT |
561 | kmem_cache_free(fs_cachep, fs); |
562 | } | |
563 | } | |
564 | ||
1ec7f1dd | 565 | void exit_fs(struct task_struct *tsk) |
1da177e4 LT |
566 | { |
567 | struct fs_struct * fs = tsk->fs; | |
568 | ||
569 | if (fs) { | |
570 | task_lock(tsk); | |
571 | tsk->fs = NULL; | |
572 | task_unlock(tsk); | |
1ec7f1dd | 573 | put_fs_struct(fs); |
1da177e4 LT |
574 | } |
575 | } | |
576 | ||
1da177e4 LT |
577 | EXPORT_SYMBOL_GPL(exit_fs); |
578 | ||
cf475ad2 BS |
579 | #ifdef CONFIG_MM_OWNER |
580 | /* | |
581 | * Task p is exiting and it owned mm, lets find a new owner for it | |
582 | */ | |
583 | static inline int | |
584 | mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) | |
585 | { | |
586 | /* | |
587 | * If there are other users of the mm and the owner (us) is exiting | |
588 | * we need to find a new owner to take on the responsibility. | |
589 | */ | |
cf475ad2 BS |
590 | if (atomic_read(&mm->mm_users) <= 1) |
591 | return 0; | |
592 | if (mm->owner != p) | |
593 | return 0; | |
594 | return 1; | |
595 | } | |
596 | ||
597 | void mm_update_next_owner(struct mm_struct *mm) | |
598 | { | |
599 | struct task_struct *c, *g, *p = current; | |
600 | ||
601 | retry: | |
602 | if (!mm_need_new_owner(mm, p)) | |
603 | return; | |
604 | ||
605 | read_lock(&tasklist_lock); | |
606 | /* | |
607 | * Search in the children | |
608 | */ | |
609 | list_for_each_entry(c, &p->children, sibling) { | |
610 | if (c->mm == mm) | |
611 | goto assign_new_owner; | |
612 | } | |
613 | ||
614 | /* | |
615 | * Search in the siblings | |
616 | */ | |
617 | list_for_each_entry(c, &p->parent->children, sibling) { | |
618 | if (c->mm == mm) | |
619 | goto assign_new_owner; | |
620 | } | |
621 | ||
622 | /* | |
623 | * Search through everything else. We should not get | |
624 | * here often | |
625 | */ | |
626 | do_each_thread(g, c) { | |
627 | if (c->mm == mm) | |
628 | goto assign_new_owner; | |
629 | } while_each_thread(g, c); | |
630 | ||
631 | read_unlock(&tasklist_lock); | |
31a78f23 BS |
632 | /* |
633 | * We found no owner yet mm_users > 1: this implies that we are | |
634 | * most likely racing with swapoff (try_to_unuse()) or /proc or | |
635 | * ptrace or page migration (get_task_mm()). Mark owner as NULL, | |
636 | * so that subsystems can understand the callback and take action. | |
637 | */ | |
638 | down_write(&mm->mmap_sem); | |
639 | cgroup_mm_owner_callbacks(mm->owner, NULL); | |
640 | mm->owner = NULL; | |
641 | up_write(&mm->mmap_sem); | |
cf475ad2 BS |
642 | return; |
643 | ||
644 | assign_new_owner: | |
645 | BUG_ON(c == p); | |
646 | get_task_struct(c); | |
9363b9f2 BS |
647 | read_unlock(&tasklist_lock); |
648 | down_write(&mm->mmap_sem); | |
cf475ad2 BS |
649 | /* |
650 | * The task_lock protects c->mm from changing. | |
651 | * We always want mm->owner->mm == mm | |
652 | */ | |
653 | task_lock(c); | |
cf475ad2 BS |
654 | if (c->mm != mm) { |
655 | task_unlock(c); | |
9363b9f2 | 656 | up_write(&mm->mmap_sem); |
cf475ad2 BS |
657 | put_task_struct(c); |
658 | goto retry; | |
659 | } | |
660 | cgroup_mm_owner_callbacks(mm->owner, c); | |
661 | mm->owner = c; | |
662 | task_unlock(c); | |
9363b9f2 | 663 | up_write(&mm->mmap_sem); |
cf475ad2 BS |
664 | put_task_struct(c); |
665 | } | |
666 | #endif /* CONFIG_MM_OWNER */ | |
667 | ||
1da177e4 LT |
668 | /* |
669 | * Turn us into a lazy TLB process if we | |
670 | * aren't already.. | |
671 | */ | |
408b664a | 672 | static void exit_mm(struct task_struct * tsk) |
1da177e4 LT |
673 | { |
674 | struct mm_struct *mm = tsk->mm; | |
b564daf8 | 675 | struct core_state *core_state; |
1da177e4 LT |
676 | |
677 | mm_release(tsk, mm); | |
678 | if (!mm) | |
679 | return; | |
680 | /* | |
681 | * Serialize with any possible pending coredump. | |
999d9fc1 | 682 | * We must hold mmap_sem around checking core_state |
1da177e4 | 683 | * and clearing tsk->mm. The core-inducing thread |
999d9fc1 | 684 | * will increment ->nr_threads for each thread in the |
1da177e4 LT |
685 | * group with ->mm != NULL. |
686 | */ | |
687 | down_read(&mm->mmap_sem); | |
b564daf8 ON |
688 | core_state = mm->core_state; |
689 | if (core_state) { | |
690 | struct core_thread self; | |
1da177e4 | 691 | up_read(&mm->mmap_sem); |
c5f1cc8c | 692 | |
b564daf8 ON |
693 | self.task = tsk; |
694 | self.next = xchg(&core_state->dumper.next, &self); | |
695 | /* | |
696 | * Implies mb(), the result of xchg() must be visible | |
697 | * to core_state->dumper. | |
698 | */ | |
699 | if (atomic_dec_and_test(&core_state->nr_threads)) | |
700 | complete(&core_state->startup); | |
1da177e4 | 701 | |
a94e2d40 ON |
702 | for (;;) { |
703 | set_task_state(tsk, TASK_UNINTERRUPTIBLE); | |
704 | if (!self.task) /* see coredump_finish() */ | |
705 | break; | |
706 | schedule(); | |
707 | } | |
708 | __set_task_state(tsk, TASK_RUNNING); | |
1da177e4 LT |
709 | down_read(&mm->mmap_sem); |
710 | } | |
711 | atomic_inc(&mm->mm_count); | |
125e1874 | 712 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
713 | /* more a memory barrier than a real lock */ |
714 | task_lock(tsk); | |
715 | tsk->mm = NULL; | |
716 | up_read(&mm->mmap_sem); | |
717 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
718 | /* We don't want this task to be frozen prematurely */ |
719 | clear_freeze_flag(tsk); | |
1da177e4 | 720 | task_unlock(tsk); |
cf475ad2 | 721 | mm_update_next_owner(mm); |
1da177e4 LT |
722 | mmput(mm); |
723 | } | |
724 | ||
666f164f RM |
725 | /* |
726 | * Return nonzero if @parent's children should reap themselves. | |
727 | * | |
728 | * Called with write_lock_irq(&tasklist_lock) held. | |
729 | */ | |
730 | static int ignoring_children(struct task_struct *parent) | |
731 | { | |
732 | int ret; | |
733 | struct sighand_struct *psig = parent->sighand; | |
734 | unsigned long flags; | |
735 | spin_lock_irqsave(&psig->siglock, flags); | |
736 | ret = (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || | |
737 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT)); | |
738 | spin_unlock_irqrestore(&psig->siglock, flags); | |
739 | return ret; | |
740 | } | |
741 | ||
f470021a RM |
742 | /* |
743 | * Detach all tasks we were using ptrace on. | |
744 | * Any that need to be release_task'd are put on the @dead list. | |
745 | * | |
746 | * Called with write_lock(&tasklist_lock) held. | |
747 | */ | |
748 | static void ptrace_exit(struct task_struct *parent, struct list_head *dead) | |
1da177e4 | 749 | { |
f470021a | 750 | struct task_struct *p, *n; |
666f164f | 751 | int ign = -1; |
241ceee0 | 752 | |
f470021a RM |
753 | list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) { |
754 | __ptrace_unlink(p); | |
755 | ||
756 | if (p->exit_state != EXIT_ZOMBIE) | |
757 | continue; | |
758 | ||
759 | /* | |
760 | * If it's a zombie, our attachedness prevented normal | |
761 | * parent notification or self-reaping. Do notification | |
762 | * now if it would have happened earlier. If it should | |
763 | * reap itself, add it to the @dead list. We can't call | |
764 | * release_task() here because we already hold tasklist_lock. | |
765 | * | |
766 | * If it's our own child, there is no notification to do. | |
666f164f RM |
767 | * But if our normal children self-reap, then this child |
768 | * was prevented by ptrace and we must reap it now. | |
1da177e4 | 769 | */ |
f470021a RM |
770 | if (!task_detached(p) && thread_group_empty(p)) { |
771 | if (!same_thread_group(p->real_parent, parent)) | |
772 | do_notify_parent(p, p->exit_signal); | |
666f164f RM |
773 | else { |
774 | if (ign < 0) | |
775 | ign = ignoring_children(parent); | |
776 | if (ign) | |
777 | p->exit_signal = -1; | |
778 | } | |
f470021a | 779 | } |
1da177e4 | 780 | |
f470021a | 781 | if (task_detached(p)) { |
1da177e4 | 782 | /* |
f470021a | 783 | * Mark it as in the process of being reaped. |
1da177e4 | 784 | */ |
f470021a RM |
785 | p->exit_state = EXIT_DEAD; |
786 | list_add(&p->ptrace_entry, dead); | |
1da177e4 LT |
787 | } |
788 | } | |
f470021a RM |
789 | } |
790 | ||
791 | /* | |
792 | * Finish up exit-time ptrace cleanup. | |
793 | * | |
794 | * Called without locks. | |
795 | */ | |
796 | static void ptrace_exit_finish(struct task_struct *parent, | |
797 | struct list_head *dead) | |
798 | { | |
799 | struct task_struct *p, *n; | |
800 | ||
801 | BUG_ON(!list_empty(&parent->ptraced)); | |
802 | ||
803 | list_for_each_entry_safe(p, n, dead, ptrace_entry) { | |
804 | list_del_init(&p->ptrace_entry); | |
805 | release_task(p); | |
806 | } | |
807 | } | |
808 | ||
809 | static void reparent_thread(struct task_struct *p, struct task_struct *father) | |
810 | { | |
811 | if (p->pdeath_signal) | |
812 | /* We already hold the tasklist_lock here. */ | |
813 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
814 | ||
815 | list_move_tail(&p->sibling, &p->real_parent->children); | |
1da177e4 | 816 | |
b2b2cbc4 EB |
817 | /* If this is a threaded reparent there is no need to |
818 | * notify anyone anything has happened. | |
819 | */ | |
376e1d25 | 820 | if (same_thread_group(p->real_parent, father)) |
b2b2cbc4 EB |
821 | return; |
822 | ||
823 | /* We don't want people slaying init. */ | |
d839fd4d | 824 | if (!task_detached(p)) |
b2b2cbc4 | 825 | p->exit_signal = SIGCHLD; |
b2b2cbc4 EB |
826 | |
827 | /* If we'd notified the old parent about this child's death, | |
828 | * also notify the new parent. | |
829 | */ | |
f470021a RM |
830 | if (!ptrace_reparented(p) && |
831 | p->exit_state == EXIT_ZOMBIE && | |
d839fd4d | 832 | !task_detached(p) && thread_group_empty(p)) |
b2b2cbc4 EB |
833 | do_notify_parent(p, p->exit_signal); |
834 | ||
f49ee505 | 835 | kill_orphaned_pgrp(p, father); |
1da177e4 LT |
836 | } |
837 | ||
838 | /* | |
839 | * When we die, we re-parent all our children. | |
840 | * Try to give them to another thread in our thread | |
841 | * group, and if no such member exists, give it to | |
84d73786 SB |
842 | * the child reaper process (ie "init") in our pid |
843 | * space. | |
1da177e4 | 844 | */ |
950bbabb ON |
845 | static struct task_struct *find_new_reaper(struct task_struct *father) |
846 | { | |
847 | struct pid_namespace *pid_ns = task_active_pid_ns(father); | |
848 | struct task_struct *thread; | |
849 | ||
850 | thread = father; | |
851 | while_each_thread(father, thread) { | |
852 | if (thread->flags & PF_EXITING) | |
853 | continue; | |
854 | if (unlikely(pid_ns->child_reaper == father)) | |
855 | pid_ns->child_reaper = thread; | |
856 | return thread; | |
857 | } | |
858 | ||
859 | if (unlikely(pid_ns->child_reaper == father)) { | |
860 | write_unlock_irq(&tasklist_lock); | |
861 | if (unlikely(pid_ns == &init_pid_ns)) | |
862 | panic("Attempted to kill init!"); | |
863 | ||
864 | zap_pid_ns_processes(pid_ns); | |
865 | write_lock_irq(&tasklist_lock); | |
866 | /* | |
867 | * We can not clear ->child_reaper or leave it alone. | |
868 | * There may by stealth EXIT_DEAD tasks on ->children, | |
869 | * forget_original_parent() must move them somewhere. | |
870 | */ | |
871 | pid_ns->child_reaper = init_pid_ns.child_reaper; | |
872 | } | |
873 | ||
874 | return pid_ns->child_reaper; | |
875 | } | |
876 | ||
762a24be | 877 | static void forget_original_parent(struct task_struct *father) |
1da177e4 | 878 | { |
950bbabb | 879 | struct task_struct *p, *n, *reaper; |
f470021a | 880 | LIST_HEAD(ptrace_dead); |
762a24be ON |
881 | |
882 | write_lock_irq(&tasklist_lock); | |
950bbabb | 883 | reaper = find_new_reaper(father); |
f470021a RM |
884 | /* |
885 | * First clean up ptrace if we were using it. | |
886 | */ | |
887 | ptrace_exit(father, &ptrace_dead); | |
888 | ||
03ff1797 | 889 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
84eb646b | 890 | p->real_parent = reaper; |
f470021a RM |
891 | if (p->parent == father) { |
892 | BUG_ON(p->ptrace); | |
893 | p->parent = p->real_parent; | |
894 | } | |
895 | reparent_thread(p, father); | |
1da177e4 | 896 | } |
762a24be ON |
897 | |
898 | write_unlock_irq(&tasklist_lock); | |
899 | BUG_ON(!list_empty(&father->children)); | |
762a24be | 900 | |
f470021a | 901 | ptrace_exit_finish(father, &ptrace_dead); |
1da177e4 LT |
902 | } |
903 | ||
904 | /* | |
905 | * Send signals to all our closest relatives so that they know | |
906 | * to properly mourn us.. | |
907 | */ | |
821c7de7 | 908 | static void exit_notify(struct task_struct *tsk, int group_dead) |
1da177e4 | 909 | { |
2b2a1ff6 RM |
910 | int signal; |
911 | void *cookie; | |
1da177e4 | 912 | |
1da177e4 LT |
913 | /* |
914 | * This does two things: | |
915 | * | |
916 | * A. Make init inherit all the child processes | |
917 | * B. Check to see if any process groups have become orphaned | |
918 | * as a result of our exiting, and if they have any stopped | |
919 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
920 | */ | |
762a24be | 921 | forget_original_parent(tsk); |
2e4a7072 | 922 | exit_task_namespaces(tsk); |
1da177e4 | 923 | |
762a24be | 924 | write_lock_irq(&tasklist_lock); |
821c7de7 ON |
925 | if (group_dead) |
926 | kill_orphaned_pgrp(tsk->group_leader, NULL); | |
1da177e4 | 927 | |
24728448 | 928 | /* Let father know we died |
1da177e4 LT |
929 | * |
930 | * Thread signals are configurable, but you aren't going to use | |
d4c5e41f | 931 | * that to send signals to arbitary processes. |
1da177e4 LT |
932 | * That stops right now. |
933 | * | |
934 | * If the parent exec id doesn't match the exec id we saved | |
935 | * when we started then we know the parent has changed security | |
936 | * domain. | |
937 | * | |
938 | * If our self_exec id doesn't match our parent_exec_id then | |
939 | * we have changed execution domain as these two values started | |
940 | * the same after a fork. | |
1da177e4 | 941 | */ |
d839fd4d | 942 | if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) && |
f49ee505 | 943 | (tsk->parent_exec_id != tsk->real_parent->self_exec_id || |
d839fd4d ON |
944 | tsk->self_exec_id != tsk->parent_exec_id) && |
945 | !capable(CAP_KILL)) | |
1da177e4 LT |
946 | tsk->exit_signal = SIGCHLD; |
947 | ||
2b2a1ff6 | 948 | signal = tracehook_notify_death(tsk, &cookie, group_dead); |
5c7edcd7 | 949 | if (signal >= 0) |
2b2a1ff6 | 950 | signal = do_notify_parent(tsk, signal); |
1da177e4 | 951 | |
5c7edcd7 | 952 | tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE; |
1da177e4 | 953 | |
2800d8d1 | 954 | /* mt-exec, de_thread() is waiting for us */ |
6db840fa | 955 | if (thread_group_leader(tsk) && |
2633f0e5 SV |
956 | tsk->signal->group_exit_task && |
957 | tsk->signal->notify_count < 0) | |
6db840fa ON |
958 | wake_up_process(tsk->signal->group_exit_task); |
959 | ||
1da177e4 LT |
960 | write_unlock_irq(&tasklist_lock); |
961 | ||
2b2a1ff6 RM |
962 | tracehook_report_death(tsk, signal, cookie, group_dead); |
963 | ||
1da177e4 | 964 | /* If the process is dead, release it - nobody will wait for it */ |
5c7edcd7 | 965 | if (signal == DEATH_REAP) |
1da177e4 | 966 | release_task(tsk); |
1da177e4 LT |
967 | } |
968 | ||
e18eecb8 JD |
969 | #ifdef CONFIG_DEBUG_STACK_USAGE |
970 | static void check_stack_usage(void) | |
971 | { | |
972 | static DEFINE_SPINLOCK(low_water_lock); | |
973 | static int lowest_to_date = THREAD_SIZE; | |
974 | unsigned long *n = end_of_stack(current); | |
975 | unsigned long free; | |
976 | ||
977 | while (*n == 0) | |
978 | n++; | |
979 | free = (unsigned long)n - (unsigned long)end_of_stack(current); | |
980 | ||
981 | if (free >= lowest_to_date) | |
982 | return; | |
983 | ||
984 | spin_lock(&low_water_lock); | |
985 | if (free < lowest_to_date) { | |
986 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
987 | "left\n", | |
988 | current->comm, free); | |
989 | lowest_to_date = free; | |
990 | } | |
991 | spin_unlock(&low_water_lock); | |
992 | } | |
993 | #else | |
994 | static inline void check_stack_usage(void) {} | |
995 | #endif | |
996 | ||
7ad5b3a5 | 997 | NORET_TYPE void do_exit(long code) |
1da177e4 LT |
998 | { |
999 | struct task_struct *tsk = current; | |
1000 | int group_dead; | |
1001 | ||
1002 | profile_task_exit(tsk); | |
1003 | ||
22e2c507 JA |
1004 | WARN_ON(atomic_read(&tsk->fs_excl)); |
1005 | ||
1da177e4 LT |
1006 | if (unlikely(in_interrupt())) |
1007 | panic("Aiee, killing interrupt handler!"); | |
1008 | if (unlikely(!tsk->pid)) | |
1009 | panic("Attempted to kill the idle task!"); | |
1da177e4 | 1010 | |
30199f5a | 1011 | tracehook_report_exit(&code); |
1da177e4 | 1012 | |
df164db5 AN |
1013 | /* |
1014 | * We're taking recursive faults here in do_exit. Safest is to just | |
1015 | * leave this task alone and wait for reboot. | |
1016 | */ | |
1017 | if (unlikely(tsk->flags & PF_EXITING)) { | |
1018 | printk(KERN_ALERT | |
1019 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
1020 | /* |
1021 | * We can do this unlocked here. The futex code uses | |
1022 | * this flag just to verify whether the pi state | |
1023 | * cleanup has been done or not. In the worst case it | |
1024 | * loops once more. We pretend that the cleanup was | |
1025 | * done as there is no way to return. Either the | |
1026 | * OWNER_DIED bit is set by now or we push the blocked | |
1027 | * task into the wait for ever nirwana as well. | |
1028 | */ | |
1029 | tsk->flags |= PF_EXITPIDONE; | |
afc847b7 AV |
1030 | if (tsk->io_context) |
1031 | exit_io_context(); | |
df164db5 AN |
1032 | set_current_state(TASK_UNINTERRUPTIBLE); |
1033 | schedule(); | |
1034 | } | |
1035 | ||
d12619b5 | 1036 | exit_signals(tsk); /* sets PF_EXITING */ |
778e9a9c AK |
1037 | /* |
1038 | * tsk->flags are checked in the futex code to protect against | |
1039 | * an exiting task cleaning up the robust pi futexes. | |
1040 | */ | |
d2ee7198 ON |
1041 | smp_mb(); |
1042 | spin_unlock_wait(&tsk->pi_lock); | |
1da177e4 | 1043 | |
1da177e4 LT |
1044 | if (unlikely(in_atomic())) |
1045 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
ba25f9dc | 1046 | current->comm, task_pid_nr(current), |
1da177e4 LT |
1047 | preempt_count()); |
1048 | ||
1049 | acct_update_integrals(tsk); | |
365e9c87 HD |
1050 | if (tsk->mm) { |
1051 | update_hiwater_rss(tsk->mm); | |
1052 | update_hiwater_vm(tsk->mm); | |
1053 | } | |
1da177e4 | 1054 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 1055 | if (group_dead) { |
778e9a9c | 1056 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 1057 | exit_itimers(tsk->signal); |
c3068951 | 1058 | } |
f6ec29a4 | 1059 | acct_collect(code, group_dead); |
42b2dd0a | 1060 | #ifdef CONFIG_FUTEX |
0771dfef IM |
1061 | if (unlikely(tsk->robust_list)) |
1062 | exit_robust_list(tsk); | |
42b2dd0a | 1063 | #ifdef CONFIG_COMPAT |
34f192c6 IM |
1064 | if (unlikely(tsk->compat_robust_list)) |
1065 | compat_exit_robust_list(tsk); | |
42b2dd0a | 1066 | #endif |
34f192c6 | 1067 | #endif |
522ed776 MT |
1068 | if (group_dead) |
1069 | tty_audit_exit(); | |
fa84cb93 AV |
1070 | if (unlikely(tsk->audit_context)) |
1071 | audit_free(tsk); | |
115085ea | 1072 | |
f2ab6d88 | 1073 | tsk->exit_code = code; |
115085ea | 1074 | taskstats_exit(tsk, group_dead); |
c757249a | 1075 | |
1da177e4 LT |
1076 | exit_mm(tsk); |
1077 | ||
0e464814 | 1078 | if (group_dead) |
f6ec29a4 | 1079 | acct_process(); |
0a16b607 MD |
1080 | trace_sched_process_exit(tsk); |
1081 | ||
1da177e4 | 1082 | exit_sem(tsk); |
1ec7f1dd AV |
1083 | exit_files(tsk); |
1084 | exit_fs(tsk); | |
e18eecb8 | 1085 | check_stack_usage(); |
1da177e4 | 1086 | exit_thread(); |
b4f48b63 | 1087 | cgroup_exit(tsk, 1); |
1da177e4 LT |
1088 | exit_keys(tsk); |
1089 | ||
1090 | if (group_dead && tsk->signal->leader) | |
1091 | disassociate_ctty(1); | |
1092 | ||
a1261f54 | 1093 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
1094 | if (tsk->binfmt) |
1095 | module_put(tsk->binfmt->module); | |
1096 | ||
9f46080c | 1097 | proc_exit_connector(tsk); |
821c7de7 | 1098 | exit_notify(tsk, group_dead); |
1da177e4 | 1099 | #ifdef CONFIG_NUMA |
f0be3d32 | 1100 | mpol_put(tsk->mempolicy); |
1da177e4 LT |
1101 | tsk->mempolicy = NULL; |
1102 | #endif | |
42b2dd0a | 1103 | #ifdef CONFIG_FUTEX |
c87e2837 IM |
1104 | /* |
1105 | * This must happen late, after the PID is not | |
1106 | * hashed anymore: | |
1107 | */ | |
1108 | if (unlikely(!list_empty(&tsk->pi_state_list))) | |
1109 | exit_pi_state_list(tsk); | |
1110 | if (unlikely(current->pi_state_cache)) | |
1111 | kfree(current->pi_state_cache); | |
42b2dd0a | 1112 | #endif |
de5097c2 | 1113 | /* |
9a11b49a | 1114 | * Make sure we are holding no locks: |
de5097c2 | 1115 | */ |
9a11b49a | 1116 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1117 | /* |
1118 | * We can do this unlocked here. The futex code uses this flag | |
1119 | * just to verify whether the pi state cleanup has been done | |
1120 | * or not. In the worst case it loops once more. | |
1121 | */ | |
1122 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1123 | |
afc847b7 AV |
1124 | if (tsk->io_context) |
1125 | exit_io_context(); | |
1126 | ||
b92ce558 JA |
1127 | if (tsk->splice_pipe) |
1128 | __free_pipe_info(tsk->splice_pipe); | |
1129 | ||
7407251a | 1130 | preempt_disable(); |
55a101f8 | 1131 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1132 | tsk->state = TASK_DEAD; |
7407251a | 1133 | |
1da177e4 LT |
1134 | schedule(); |
1135 | BUG(); | |
1136 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1137 | for (;;) |
1138 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1139 | } |
1140 | ||
012914da RA |
1141 | EXPORT_SYMBOL_GPL(do_exit); |
1142 | ||
1da177e4 LT |
1143 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1144 | { | |
1145 | if (comp) | |
1146 | complete(comp); | |
55a101f8 | 1147 | |
1da177e4 LT |
1148 | do_exit(code); |
1149 | } | |
1150 | ||
1151 | EXPORT_SYMBOL(complete_and_exit); | |
1152 | ||
1153 | asmlinkage long sys_exit(int error_code) | |
1154 | { | |
1155 | do_exit((error_code&0xff)<<8); | |
1156 | } | |
1157 | ||
1da177e4 LT |
1158 | /* |
1159 | * Take down every thread in the group. This is called by fatal signals | |
1160 | * as well as by sys_exit_group (below). | |
1161 | */ | |
1162 | NORET_TYPE void | |
1163 | do_group_exit(int exit_code) | |
1164 | { | |
bfc4b089 ON |
1165 | struct signal_struct *sig = current->signal; |
1166 | ||
1da177e4 LT |
1167 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
1168 | ||
bfc4b089 ON |
1169 | if (signal_group_exit(sig)) |
1170 | exit_code = sig->group_exit_code; | |
1da177e4 | 1171 | else if (!thread_group_empty(current)) { |
1da177e4 | 1172 | struct sighand_struct *const sighand = current->sighand; |
1da177e4 | 1173 | spin_lock_irq(&sighand->siglock); |
ed5d2cac | 1174 | if (signal_group_exit(sig)) |
1da177e4 LT |
1175 | /* Another thread got here before we took the lock. */ |
1176 | exit_code = sig->group_exit_code; | |
1177 | else { | |
1da177e4 | 1178 | sig->group_exit_code = exit_code; |
ed5d2cac | 1179 | sig->flags = SIGNAL_GROUP_EXIT; |
1da177e4 LT |
1180 | zap_other_threads(current); |
1181 | } | |
1182 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1183 | } |
1184 | ||
1185 | do_exit(exit_code); | |
1186 | /* NOTREACHED */ | |
1187 | } | |
1188 | ||
1189 | /* | |
1190 | * this kills every thread in the thread group. Note that any externally | |
1191 | * wait4()-ing process will get the correct exit code - even if this | |
1192 | * thread is not the thread group leader. | |
1193 | */ | |
1194 | asmlinkage void sys_exit_group(int error_code) | |
1195 | { | |
1196 | do_group_exit((error_code & 0xff) << 8); | |
1197 | } | |
1198 | ||
161550d7 EB |
1199 | static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) |
1200 | { | |
1201 | struct pid *pid = NULL; | |
1202 | if (type == PIDTYPE_PID) | |
1203 | pid = task->pids[type].pid; | |
1204 | else if (type < PIDTYPE_MAX) | |
1205 | pid = task->group_leader->pids[type].pid; | |
1206 | return pid; | |
1207 | } | |
1208 | ||
1209 | static int eligible_child(enum pid_type type, struct pid *pid, int options, | |
1210 | struct task_struct *p) | |
1da177e4 | 1211 | { |
73243284 RM |
1212 | int err; |
1213 | ||
161550d7 EB |
1214 | if (type < PIDTYPE_MAX) { |
1215 | if (task_pid_type(p, type) != pid) | |
1da177e4 LT |
1216 | return 0; |
1217 | } | |
1218 | ||
1da177e4 LT |
1219 | /* Wait for all children (clone and not) if __WALL is set; |
1220 | * otherwise, wait for clone children *only* if __WCLONE is | |
1221 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1222 | * A "clone" child here is one that reports to its parent | |
1223 | * using a signal other than SIGCHLD.) */ | |
1224 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1225 | && !(options & __WALL)) | |
1226 | return 0; | |
1da177e4 | 1227 | |
73243284 | 1228 | err = security_task_wait(p); |
14dd0b81 RM |
1229 | if (err) |
1230 | return err; | |
1da177e4 | 1231 | |
14dd0b81 | 1232 | return 1; |
1da177e4 LT |
1233 | } |
1234 | ||
36c8b586 | 1235 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1236 | int why, int status, |
1237 | struct siginfo __user *infop, | |
1238 | struct rusage __user *rusagep) | |
1239 | { | |
1240 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1241 | |
1da177e4 LT |
1242 | put_task_struct(p); |
1243 | if (!retval) | |
1244 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1245 | if (!retval) | |
1246 | retval = put_user(0, &infop->si_errno); | |
1247 | if (!retval) | |
1248 | retval = put_user((short)why, &infop->si_code); | |
1249 | if (!retval) | |
1250 | retval = put_user(pid, &infop->si_pid); | |
1251 | if (!retval) | |
1252 | retval = put_user(uid, &infop->si_uid); | |
1253 | if (!retval) | |
1254 | retval = put_user(status, &infop->si_status); | |
1255 | if (!retval) | |
1256 | retval = pid; | |
1257 | return retval; | |
1258 | } | |
1259 | ||
1260 | /* | |
1261 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1262 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1263 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1264 | * released the lock and the system call should return. | |
1265 | */ | |
98abed02 | 1266 | static int wait_task_zombie(struct task_struct *p, int options, |
1da177e4 LT |
1267 | struct siginfo __user *infop, |
1268 | int __user *stat_addr, struct rusage __user *ru) | |
1269 | { | |
1270 | unsigned long state; | |
2f4e6e2a | 1271 | int retval, status, traced; |
6c5f3e7b | 1272 | pid_t pid = task_pid_vnr(p); |
c69e8d9c | 1273 | uid_t uid = __task_cred(p)->uid; |
1da177e4 | 1274 | |
98abed02 RM |
1275 | if (!likely(options & WEXITED)) |
1276 | return 0; | |
1277 | ||
1278 | if (unlikely(options & WNOWAIT)) { | |
1da177e4 LT |
1279 | int exit_code = p->exit_code; |
1280 | int why, status; | |
1281 | ||
1da177e4 LT |
1282 | get_task_struct(p); |
1283 | read_unlock(&tasklist_lock); | |
1284 | if ((exit_code & 0x7f) == 0) { | |
1285 | why = CLD_EXITED; | |
1286 | status = exit_code >> 8; | |
1287 | } else { | |
1288 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1289 | status = exit_code & 0x7f; | |
1290 | } | |
1291 | return wait_noreap_copyout(p, pid, uid, why, | |
1292 | status, infop, ru); | |
1293 | } | |
1294 | ||
1295 | /* | |
1296 | * Try to move the task's state to DEAD | |
1297 | * only one thread is allowed to do this: | |
1298 | */ | |
1299 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1300 | if (state != EXIT_ZOMBIE) { | |
1301 | BUG_ON(state != EXIT_DEAD); | |
1302 | return 0; | |
1303 | } | |
1da177e4 | 1304 | |
53b6f9fb | 1305 | traced = ptrace_reparented(p); |
2f4e6e2a ON |
1306 | |
1307 | if (likely(!traced)) { | |
3795e161 JJ |
1308 | struct signal_struct *psig; |
1309 | struct signal_struct *sig; | |
f06febc9 | 1310 | struct task_cputime cputime; |
3795e161 | 1311 | |
1da177e4 LT |
1312 | /* |
1313 | * The resource counters for the group leader are in its | |
1314 | * own task_struct. Those for dead threads in the group | |
1315 | * are in its signal_struct, as are those for the child | |
1316 | * processes it has previously reaped. All these | |
1317 | * accumulate in the parent's signal_struct c* fields. | |
1318 | * | |
1319 | * We don't bother to take a lock here to protect these | |
1320 | * p->signal fields, because they are only touched by | |
1321 | * __exit_signal, which runs with tasklist_lock | |
1322 | * write-locked anyway, and so is excluded here. We do | |
1323 | * need to protect the access to p->parent->signal fields, | |
1324 | * as other threads in the parent group can be right | |
1325 | * here reaping other children at the same time. | |
f06febc9 FM |
1326 | * |
1327 | * We use thread_group_cputime() to get times for the thread | |
1328 | * group, which consolidates times for all threads in the | |
1329 | * group including the group leader. | |
1da177e4 LT |
1330 | */ |
1331 | spin_lock_irq(&p->parent->sighand->siglock); | |
3795e161 JJ |
1332 | psig = p->parent->signal; |
1333 | sig = p->signal; | |
f06febc9 | 1334 | thread_group_cputime(p, &cputime); |
3795e161 JJ |
1335 | psig->cutime = |
1336 | cputime_add(psig->cutime, | |
f06febc9 FM |
1337 | cputime_add(cputime.utime, |
1338 | sig->cutime)); | |
3795e161 JJ |
1339 | psig->cstime = |
1340 | cputime_add(psig->cstime, | |
f06febc9 FM |
1341 | cputime_add(cputime.stime, |
1342 | sig->cstime)); | |
9ac52315 LV |
1343 | psig->cgtime = |
1344 | cputime_add(psig->cgtime, | |
1345 | cputime_add(p->gtime, | |
1346 | cputime_add(sig->gtime, | |
1347 | sig->cgtime))); | |
3795e161 JJ |
1348 | psig->cmin_flt += |
1349 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1350 | psig->cmaj_flt += | |
1351 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1352 | psig->cnvcsw += | |
1353 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1354 | psig->cnivcsw += | |
1355 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1356 | psig->cinblock += |
1357 | task_io_get_inblock(p) + | |
1358 | sig->inblock + sig->cinblock; | |
1359 | psig->coublock += | |
1360 | task_io_get_oublock(p) + | |
1361 | sig->oublock + sig->coublock; | |
5995477a AR |
1362 | task_io_accounting_add(&psig->ioac, &p->ioac); |
1363 | task_io_accounting_add(&psig->ioac, &sig->ioac); | |
1da177e4 LT |
1364 | spin_unlock_irq(&p->parent->sighand->siglock); |
1365 | } | |
1366 | ||
1367 | /* | |
1368 | * Now we are sure this task is interesting, and no other | |
1369 | * thread can reap it because we set its state to EXIT_DEAD. | |
1370 | */ | |
1371 | read_unlock(&tasklist_lock); | |
1372 | ||
1373 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1374 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1375 | ? p->signal->group_exit_code : p->exit_code; | |
1376 | if (!retval && stat_addr) | |
1377 | retval = put_user(status, stat_addr); | |
1378 | if (!retval && infop) | |
1379 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1380 | if (!retval && infop) | |
1381 | retval = put_user(0, &infop->si_errno); | |
1382 | if (!retval && infop) { | |
1383 | int why; | |
1384 | ||
1385 | if ((status & 0x7f) == 0) { | |
1386 | why = CLD_EXITED; | |
1387 | status >>= 8; | |
1388 | } else { | |
1389 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1390 | status &= 0x7f; | |
1391 | } | |
1392 | retval = put_user((short)why, &infop->si_code); | |
1393 | if (!retval) | |
1394 | retval = put_user(status, &infop->si_status); | |
1395 | } | |
1396 | if (!retval && infop) | |
3a515e4a | 1397 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1398 | if (!retval && infop) |
c69e8d9c | 1399 | retval = put_user(uid, &infop->si_uid); |
2f4e6e2a | 1400 | if (!retval) |
3a515e4a | 1401 | retval = pid; |
2f4e6e2a ON |
1402 | |
1403 | if (traced) { | |
1da177e4 | 1404 | write_lock_irq(&tasklist_lock); |
2f4e6e2a ON |
1405 | /* We dropped tasklist, ptracer could die and untrace */ |
1406 | ptrace_unlink(p); | |
1407 | /* | |
1408 | * If this is not a detached task, notify the parent. | |
1409 | * If it's still not detached after that, don't release | |
1410 | * it now. | |
1411 | */ | |
d839fd4d | 1412 | if (!task_detached(p)) { |
2f4e6e2a | 1413 | do_notify_parent(p, p->exit_signal); |
d839fd4d | 1414 | if (!task_detached(p)) { |
2f4e6e2a ON |
1415 | p->exit_state = EXIT_ZOMBIE; |
1416 | p = NULL; | |
1da177e4 LT |
1417 | } |
1418 | } | |
1419 | write_unlock_irq(&tasklist_lock); | |
1420 | } | |
1421 | if (p != NULL) | |
1422 | release_task(p); | |
2f4e6e2a | 1423 | |
1da177e4 LT |
1424 | return retval; |
1425 | } | |
1426 | ||
1427 | /* | |
1428 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1429 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1430 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1431 | * released the lock and the system call should return. | |
1432 | */ | |
f470021a | 1433 | static int wait_task_stopped(int ptrace, struct task_struct *p, |
98abed02 | 1434 | int options, struct siginfo __user *infop, |
1da177e4 LT |
1435 | int __user *stat_addr, struct rusage __user *ru) |
1436 | { | |
ee7c82da ON |
1437 | int retval, exit_code, why; |
1438 | uid_t uid = 0; /* unneeded, required by compiler */ | |
c8950783 | 1439 | pid_t pid; |
1da177e4 | 1440 | |
f470021a | 1441 | if (!(options & WUNTRACED)) |
98abed02 RM |
1442 | return 0; |
1443 | ||
ee7c82da ON |
1444 | exit_code = 0; |
1445 | spin_lock_irq(&p->sighand->siglock); | |
1446 | ||
1447 | if (unlikely(!task_is_stopped_or_traced(p))) | |
1448 | goto unlock_sig; | |
1449 | ||
f470021a | 1450 | if (!ptrace && p->signal->group_stop_count > 0) |
1da177e4 LT |
1451 | /* |
1452 | * A group stop is in progress and this is the group leader. | |
1453 | * We won't report until all threads have stopped. | |
1454 | */ | |
ee7c82da ON |
1455 | goto unlock_sig; |
1456 | ||
1457 | exit_code = p->exit_code; | |
1458 | if (!exit_code) | |
1459 | goto unlock_sig; | |
1460 | ||
98abed02 | 1461 | if (!unlikely(options & WNOWAIT)) |
ee7c82da ON |
1462 | p->exit_code = 0; |
1463 | ||
c69e8d9c DH |
1464 | /* don't need the RCU readlock here as we're holding a spinlock */ |
1465 | uid = __task_cred(p)->uid; | |
ee7c82da ON |
1466 | unlock_sig: |
1467 | spin_unlock_irq(&p->sighand->siglock); | |
1468 | if (!exit_code) | |
1da177e4 LT |
1469 | return 0; |
1470 | ||
1471 | /* | |
1472 | * Now we are pretty sure this task is interesting. | |
1473 | * Make sure it doesn't get reaped out from under us while we | |
1474 | * give up the lock and then examine it below. We don't want to | |
1475 | * keep holding onto the tasklist_lock while we call getrusage and | |
1476 | * possibly take page faults for user memory. | |
1477 | */ | |
1478 | get_task_struct(p); | |
6c5f3e7b | 1479 | pid = task_pid_vnr(p); |
f470021a | 1480 | why = ptrace ? CLD_TRAPPED : CLD_STOPPED; |
1da177e4 LT |
1481 | read_unlock(&tasklist_lock); |
1482 | ||
98abed02 | 1483 | if (unlikely(options & WNOWAIT)) |
1da177e4 | 1484 | return wait_noreap_copyout(p, pid, uid, |
e6ceb32a | 1485 | why, exit_code, |
1da177e4 | 1486 | infop, ru); |
1da177e4 LT |
1487 | |
1488 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1489 | if (!retval && stat_addr) | |
1490 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1491 | if (!retval && infop) | |
1492 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1493 | if (!retval && infop) | |
1494 | retval = put_user(0, &infop->si_errno); | |
1495 | if (!retval && infop) | |
6efcae46 | 1496 | retval = put_user((short)why, &infop->si_code); |
1da177e4 LT |
1497 | if (!retval && infop) |
1498 | retval = put_user(exit_code, &infop->si_status); | |
1499 | if (!retval && infop) | |
c8950783 | 1500 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1501 | if (!retval && infop) |
ee7c82da | 1502 | retval = put_user(uid, &infop->si_uid); |
1da177e4 | 1503 | if (!retval) |
c8950783 | 1504 | retval = pid; |
1da177e4 LT |
1505 | put_task_struct(p); |
1506 | ||
1507 | BUG_ON(!retval); | |
1508 | return retval; | |
1509 | } | |
1510 | ||
1511 | /* | |
1512 | * Handle do_wait work for one task in a live, non-stopped state. | |
1513 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1514 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1515 | * released the lock and the system call should return. | |
1516 | */ | |
98abed02 | 1517 | static int wait_task_continued(struct task_struct *p, int options, |
1da177e4 LT |
1518 | struct siginfo __user *infop, |
1519 | int __user *stat_addr, struct rusage __user *ru) | |
1520 | { | |
1521 | int retval; | |
1522 | pid_t pid; | |
1523 | uid_t uid; | |
1524 | ||
98abed02 RM |
1525 | if (!unlikely(options & WCONTINUED)) |
1526 | return 0; | |
1527 | ||
1da177e4 LT |
1528 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
1529 | return 0; | |
1530 | ||
1531 | spin_lock_irq(&p->sighand->siglock); | |
1532 | /* Re-check with the lock held. */ | |
1533 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1534 | spin_unlock_irq(&p->sighand->siglock); | |
1535 | return 0; | |
1536 | } | |
98abed02 | 1537 | if (!unlikely(options & WNOWAIT)) |
1da177e4 | 1538 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; |
c69e8d9c | 1539 | uid = __task_cred(p)->uid; |
1da177e4 LT |
1540 | spin_unlock_irq(&p->sighand->siglock); |
1541 | ||
6c5f3e7b | 1542 | pid = task_pid_vnr(p); |
1da177e4 LT |
1543 | get_task_struct(p); |
1544 | read_unlock(&tasklist_lock); | |
1545 | ||
1546 | if (!infop) { | |
1547 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1548 | put_task_struct(p); | |
1549 | if (!retval && stat_addr) | |
1550 | retval = put_user(0xffff, stat_addr); | |
1551 | if (!retval) | |
3a515e4a | 1552 | retval = pid; |
1da177e4 LT |
1553 | } else { |
1554 | retval = wait_noreap_copyout(p, pid, uid, | |
1555 | CLD_CONTINUED, SIGCONT, | |
1556 | infop, ru); | |
1557 | BUG_ON(retval == 0); | |
1558 | } | |
1559 | ||
1560 | return retval; | |
1561 | } | |
1562 | ||
98abed02 RM |
1563 | /* |
1564 | * Consider @p for a wait by @parent. | |
1565 | * | |
1566 | * -ECHILD should be in *@notask_error before the first call. | |
1567 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1568 | * Returns zero if the search for a child should continue; | |
14dd0b81 RM |
1569 | * then *@notask_error is 0 if @p is an eligible child, |
1570 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 | 1571 | */ |
f470021a | 1572 | static int wait_consider_task(struct task_struct *parent, int ptrace, |
98abed02 RM |
1573 | struct task_struct *p, int *notask_error, |
1574 | enum pid_type type, struct pid *pid, int options, | |
1575 | struct siginfo __user *infop, | |
1576 | int __user *stat_addr, struct rusage __user *ru) | |
1577 | { | |
1578 | int ret = eligible_child(type, pid, options, p); | |
14dd0b81 | 1579 | if (!ret) |
98abed02 RM |
1580 | return ret; |
1581 | ||
14dd0b81 RM |
1582 | if (unlikely(ret < 0)) { |
1583 | /* | |
1584 | * If we have not yet seen any eligible child, | |
1585 | * then let this error code replace -ECHILD. | |
1586 | * A permission error will give the user a clue | |
1587 | * to look for security policy problems, rather | |
1588 | * than for mysterious wait bugs. | |
1589 | */ | |
1590 | if (*notask_error) | |
1591 | *notask_error = ret; | |
1592 | } | |
1593 | ||
f470021a RM |
1594 | if (likely(!ptrace) && unlikely(p->ptrace)) { |
1595 | /* | |
1596 | * This child is hidden by ptrace. | |
1597 | * We aren't allowed to see it now, but eventually we will. | |
1598 | */ | |
1599 | *notask_error = 0; | |
1600 | return 0; | |
1601 | } | |
1602 | ||
98abed02 RM |
1603 | if (p->exit_state == EXIT_DEAD) |
1604 | return 0; | |
1605 | ||
1606 | /* | |
1607 | * We don't reap group leaders with subthreads. | |
1608 | */ | |
1609 | if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p)) | |
1610 | return wait_task_zombie(p, options, infop, stat_addr, ru); | |
1611 | ||
1612 | /* | |
1613 | * It's stopped or running now, so it might | |
1614 | * later continue, exit, or stop again. | |
1615 | */ | |
1616 | *notask_error = 0; | |
1617 | ||
1618 | if (task_is_stopped_or_traced(p)) | |
f470021a RM |
1619 | return wait_task_stopped(ptrace, p, options, |
1620 | infop, stat_addr, ru); | |
98abed02 RM |
1621 | |
1622 | return wait_task_continued(p, options, infop, stat_addr, ru); | |
1623 | } | |
1624 | ||
1625 | /* | |
1626 | * Do the work of do_wait() for one thread in the group, @tsk. | |
1627 | * | |
1628 | * -ECHILD should be in *@notask_error before the first call. | |
1629 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1630 | * Returns zero if the search for a child should continue; then | |
14dd0b81 RM |
1631 | * *@notask_error is 0 if there were any eligible children, |
1632 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 RM |
1633 | */ |
1634 | static int do_wait_thread(struct task_struct *tsk, int *notask_error, | |
1635 | enum pid_type type, struct pid *pid, int options, | |
1636 | struct siginfo __user *infop, int __user *stat_addr, | |
1637 | struct rusage __user *ru) | |
1638 | { | |
1639 | struct task_struct *p; | |
1640 | ||
1641 | list_for_each_entry(p, &tsk->children, sibling) { | |
f470021a RM |
1642 | /* |
1643 | * Do not consider detached threads. | |
1644 | */ | |
1645 | if (!task_detached(p)) { | |
1646 | int ret = wait_consider_task(tsk, 0, p, notask_error, | |
1647 | type, pid, options, | |
1648 | infop, stat_addr, ru); | |
1649 | if (ret) | |
1650 | return ret; | |
1651 | } | |
98abed02 RM |
1652 | } |
1653 | ||
1654 | return 0; | |
1655 | } | |
1656 | ||
1657 | static int ptrace_do_wait(struct task_struct *tsk, int *notask_error, | |
1658 | enum pid_type type, struct pid *pid, int options, | |
1659 | struct siginfo __user *infop, int __user *stat_addr, | |
1660 | struct rusage __user *ru) | |
1661 | { | |
1662 | struct task_struct *p; | |
1663 | ||
1664 | /* | |
f470021a | 1665 | * Traditionally we see ptrace'd stopped tasks regardless of options. |
98abed02 | 1666 | */ |
f470021a | 1667 | options |= WUNTRACED; |
98abed02 | 1668 | |
f470021a RM |
1669 | list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { |
1670 | int ret = wait_consider_task(tsk, 1, p, notask_error, | |
1671 | type, pid, options, | |
1672 | infop, stat_addr, ru); | |
1673 | if (ret) | |
98abed02 | 1674 | return ret; |
98abed02 RM |
1675 | } |
1676 | ||
1677 | return 0; | |
1678 | } | |
1679 | ||
161550d7 EB |
1680 | static long do_wait(enum pid_type type, struct pid *pid, int options, |
1681 | struct siginfo __user *infop, int __user *stat_addr, | |
1682 | struct rusage __user *ru) | |
1da177e4 LT |
1683 | { |
1684 | DECLARE_WAITQUEUE(wait, current); | |
1685 | struct task_struct *tsk; | |
98abed02 | 1686 | int retval; |
1da177e4 | 1687 | |
0a16b607 MD |
1688 | trace_sched_process_wait(pid); |
1689 | ||
1da177e4 LT |
1690 | add_wait_queue(¤t->signal->wait_chldexit,&wait); |
1691 | repeat: | |
98abed02 RM |
1692 | /* |
1693 | * If there is nothing that can match our critiera just get out. | |
1694 | * We will clear @retval to zero if we see any child that might later | |
1695 | * match our criteria, even if we are not able to reap it yet. | |
1696 | */ | |
161550d7 EB |
1697 | retval = -ECHILD; |
1698 | if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) | |
1699 | goto end; | |
1700 | ||
1da177e4 LT |
1701 | current->state = TASK_INTERRUPTIBLE; |
1702 | read_lock(&tasklist_lock); | |
1703 | tsk = current; | |
1704 | do { | |
98abed02 RM |
1705 | int tsk_result = do_wait_thread(tsk, &retval, |
1706 | type, pid, options, | |
1707 | infop, stat_addr, ru); | |
1708 | if (!tsk_result) | |
1709 | tsk_result = ptrace_do_wait(tsk, &retval, | |
1710 | type, pid, options, | |
1711 | infop, stat_addr, ru); | |
1712 | if (tsk_result) { | |
1713 | /* | |
1714 | * tasklist_lock is unlocked and we have a final result. | |
1715 | */ | |
1716 | retval = tsk_result; | |
1717 | goto end; | |
1da177e4 | 1718 | } |
98abed02 | 1719 | |
1da177e4 LT |
1720 | if (options & __WNOTHREAD) |
1721 | break; | |
1722 | tsk = next_thread(tsk); | |
125e1874 | 1723 | BUG_ON(tsk->signal != current->signal); |
1da177e4 | 1724 | } while (tsk != current); |
1da177e4 | 1725 | read_unlock(&tasklist_lock); |
f2cc3eb1 | 1726 | |
98abed02 | 1727 | if (!retval && !(options & WNOHANG)) { |
1da177e4 | 1728 | retval = -ERESTARTSYS; |
98abed02 RM |
1729 | if (!signal_pending(current)) { |
1730 | schedule(); | |
1731 | goto repeat; | |
1732 | } | |
1da177e4 | 1733 | } |
98abed02 | 1734 | |
1da177e4 LT |
1735 | end: |
1736 | current->state = TASK_RUNNING; | |
1737 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1738 | if (infop) { | |
1739 | if (retval > 0) | |
9cbab810 | 1740 | retval = 0; |
1da177e4 LT |
1741 | else { |
1742 | /* | |
1743 | * For a WNOHANG return, clear out all the fields | |
1744 | * we would set so the user can easily tell the | |
1745 | * difference. | |
1746 | */ | |
1747 | if (!retval) | |
1748 | retval = put_user(0, &infop->si_signo); | |
1749 | if (!retval) | |
1750 | retval = put_user(0, &infop->si_errno); | |
1751 | if (!retval) | |
1752 | retval = put_user(0, &infop->si_code); | |
1753 | if (!retval) | |
1754 | retval = put_user(0, &infop->si_pid); | |
1755 | if (!retval) | |
1756 | retval = put_user(0, &infop->si_uid); | |
1757 | if (!retval) | |
1758 | retval = put_user(0, &infop->si_status); | |
1759 | } | |
1760 | } | |
1761 | return retval; | |
1762 | } | |
1763 | ||
161550d7 | 1764 | asmlinkage long sys_waitid(int which, pid_t upid, |
1da177e4 LT |
1765 | struct siginfo __user *infop, int options, |
1766 | struct rusage __user *ru) | |
1767 | { | |
161550d7 EB |
1768 | struct pid *pid = NULL; |
1769 | enum pid_type type; | |
1da177e4 LT |
1770 | long ret; |
1771 | ||
1772 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1773 | return -EINVAL; | |
1774 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1775 | return -EINVAL; | |
1776 | ||
1777 | switch (which) { | |
1778 | case P_ALL: | |
161550d7 | 1779 | type = PIDTYPE_MAX; |
1da177e4 LT |
1780 | break; |
1781 | case P_PID: | |
161550d7 EB |
1782 | type = PIDTYPE_PID; |
1783 | if (upid <= 0) | |
1da177e4 LT |
1784 | return -EINVAL; |
1785 | break; | |
1786 | case P_PGID: | |
161550d7 EB |
1787 | type = PIDTYPE_PGID; |
1788 | if (upid <= 0) | |
1da177e4 | 1789 | return -EINVAL; |
1da177e4 LT |
1790 | break; |
1791 | default: | |
1792 | return -EINVAL; | |
1793 | } | |
1794 | ||
161550d7 EB |
1795 | if (type < PIDTYPE_MAX) |
1796 | pid = find_get_pid(upid); | |
1797 | ret = do_wait(type, pid, options, infop, NULL, ru); | |
1798 | put_pid(pid); | |
1da177e4 LT |
1799 | |
1800 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1801 | asmlinkage_protect(5, ret, which, upid, infop, options, ru); |
1da177e4 LT |
1802 | return ret; |
1803 | } | |
1804 | ||
161550d7 | 1805 | asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr, |
1da177e4 LT |
1806 | int options, struct rusage __user *ru) |
1807 | { | |
161550d7 EB |
1808 | struct pid *pid = NULL; |
1809 | enum pid_type type; | |
1da177e4 LT |
1810 | long ret; |
1811 | ||
1812 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1813 | __WNOTHREAD|__WCLONE|__WALL)) | |
1814 | return -EINVAL; | |
161550d7 EB |
1815 | |
1816 | if (upid == -1) | |
1817 | type = PIDTYPE_MAX; | |
1818 | else if (upid < 0) { | |
1819 | type = PIDTYPE_PGID; | |
1820 | pid = find_get_pid(-upid); | |
1821 | } else if (upid == 0) { | |
1822 | type = PIDTYPE_PGID; | |
1823 | pid = get_pid(task_pgrp(current)); | |
1824 | } else /* upid > 0 */ { | |
1825 | type = PIDTYPE_PID; | |
1826 | pid = find_get_pid(upid); | |
1827 | } | |
1828 | ||
1829 | ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru); | |
1830 | put_pid(pid); | |
1da177e4 LT |
1831 | |
1832 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1833 | asmlinkage_protect(4, ret, upid, stat_addr, options, ru); |
1da177e4 LT |
1834 | return ret; |
1835 | } | |
1836 | ||
1837 | #ifdef __ARCH_WANT_SYS_WAITPID | |
1838 | ||
1839 | /* | |
1840 | * sys_waitpid() remains for compatibility. waitpid() should be | |
1841 | * implemented by calling sys_wait4() from libc.a. | |
1842 | */ | |
1843 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) | |
1844 | { | |
1845 | return sys_wait4(pid, stat_addr, options, NULL); | |
1846 | } | |
1847 | ||
1848 | #endif |