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> |
b92ce558 | 43 | #include <linux/pipe_fs_i.h> |
fa84cb93 | 44 | #include <linux/audit.h> /* for audit_free() */ |
83cc5ed3 | 45 | #include <linux/resource.h> |
0d67a46d | 46 | #include <linux/blkdev.h> |
6eaeeaba | 47 | #include <linux/task_io_accounting_ops.h> |
30199f5a | 48 | #include <linux/tracehook.h> |
5ad4e53b | 49 | #include <linux/fs_struct.h> |
d84f4f99 | 50 | #include <linux/init_task.h> |
a63eaf34 | 51 | #include <linux/perf_counter.h> |
0a16b607 | 52 | #include <trace/sched.h> |
1da177e4 LT |
53 | |
54 | #include <asm/uaccess.h> | |
55 | #include <asm/unistd.h> | |
56 | #include <asm/pgtable.h> | |
57 | #include <asm/mmu_context.h> | |
d84f4f99 | 58 | #include "cred-internals.h" |
1da177e4 | 59 | |
7e066fb8 MD |
60 | DEFINE_TRACE(sched_process_free); |
61 | DEFINE_TRACE(sched_process_exit); | |
62 | DEFINE_TRACE(sched_process_wait); | |
1da177e4 | 63 | |
408b664a AB |
64 | static void exit_mm(struct task_struct * tsk); |
65 | ||
1da177e4 LT |
66 | static void __unhash_process(struct task_struct *p) |
67 | { | |
68 | nr_threads--; | |
69 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
70 | if (thread_group_leader(p)) { |
71 | detach_pid(p, PIDTYPE_PGID); | |
72 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 73 | |
5e85d4ab | 74 | list_del_rcu(&p->tasks); |
73b9ebfe | 75 | __get_cpu_var(process_counts)--; |
1da177e4 | 76 | } |
47e65328 | 77 | list_del_rcu(&p->thread_group); |
f470021a | 78 | list_del_init(&p->sibling); |
1da177e4 LT |
79 | } |
80 | ||
6a14c5c9 ON |
81 | /* |
82 | * This function expects the tasklist_lock write-locked. | |
83 | */ | |
84 | static void __exit_signal(struct task_struct *tsk) | |
85 | { | |
86 | struct signal_struct *sig = tsk->signal; | |
87 | struct sighand_struct *sighand; | |
88 | ||
89 | BUG_ON(!sig); | |
90 | BUG_ON(!atomic_read(&sig->count)); | |
91 | ||
6a14c5c9 ON |
92 | sighand = rcu_dereference(tsk->sighand); |
93 | spin_lock(&sighand->siglock); | |
94 | ||
95 | posix_cpu_timers_exit(tsk); | |
96 | if (atomic_dec_and_test(&sig->count)) | |
97 | posix_cpu_timers_exit_group(tsk); | |
98 | else { | |
99 | /* | |
100 | * If there is any task waiting for the group exit | |
101 | * then notify it: | |
102 | */ | |
6db840fa | 103 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) |
6a14c5c9 | 104 | wake_up_process(sig->group_exit_task); |
6db840fa | 105 | |
6a14c5c9 ON |
106 | if (tsk == sig->curr_target) |
107 | sig->curr_target = next_thread(tsk); | |
108 | /* | |
109 | * Accumulate here the counters for all threads but the | |
110 | * group leader as they die, so they can be added into | |
111 | * the process-wide totals when those are taken. | |
112 | * The group leader stays around as a zombie as long | |
113 | * as there are other threads. When it gets reaped, | |
114 | * the exit.c code will add its counts into these totals. | |
115 | * We won't ever get here for the group leader, since it | |
116 | * will have been the last reference on the signal_struct. | |
117 | */ | |
32bd671d PZ |
118 | sig->utime = cputime_add(sig->utime, task_utime(tsk)); |
119 | sig->stime = cputime_add(sig->stime, task_stime(tsk)); | |
49048622 | 120 | sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); |
6a14c5c9 ON |
121 | sig->min_flt += tsk->min_flt; |
122 | sig->maj_flt += tsk->maj_flt; | |
123 | sig->nvcsw += tsk->nvcsw; | |
124 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
125 | sig->inblock += task_io_get_inblock(tsk); |
126 | sig->oublock += task_io_get_oublock(tsk); | |
5995477a | 127 | task_io_accounting_add(&sig->ioac, &tsk->ioac); |
32bd671d | 128 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
6a14c5c9 ON |
129 | sig = NULL; /* Marker for below. */ |
130 | } | |
131 | ||
5876700c ON |
132 | __unhash_process(tsk); |
133 | ||
da7978b0 ON |
134 | /* |
135 | * Do this under ->siglock, we can race with another thread | |
136 | * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals. | |
137 | */ | |
138 | flush_sigqueue(&tsk->pending); | |
139 | ||
6a14c5c9 | 140 | tsk->signal = NULL; |
a7e5328a | 141 | tsk->sighand = NULL; |
6a14c5c9 | 142 | spin_unlock(&sighand->siglock); |
6a14c5c9 | 143 | |
a7e5328a | 144 | __cleanup_sighand(sighand); |
6a14c5c9 | 145 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
6a14c5c9 ON |
146 | if (sig) { |
147 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 148 | taskstats_tgid_free(sig); |
ad474cac ON |
149 | /* |
150 | * Make sure ->signal can't go away under rq->lock, | |
151 | * see account_group_exec_runtime(). | |
152 | */ | |
153 | task_rq_unlock_wait(tsk); | |
6a14c5c9 ON |
154 | __cleanup_signal(sig); |
155 | } | |
156 | } | |
157 | ||
8c7904a0 EB |
158 | static void delayed_put_task_struct(struct rcu_head *rhp) |
159 | { | |
0a16b607 MD |
160 | struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); |
161 | ||
eef6cbf5 | 162 | #ifdef CONFIG_PERF_COUNTERS |
a63eaf34 | 163 | WARN_ON_ONCE(tsk->perf_counter_ctxp); |
eef6cbf5 | 164 | #endif |
0a16b607 MD |
165 | trace_sched_process_free(tsk); |
166 | put_task_struct(tsk); | |
8c7904a0 EB |
167 | } |
168 | ||
f470021a | 169 | |
1da177e4 LT |
170 | void release_task(struct task_struct * p) |
171 | { | |
36c8b586 | 172 | struct task_struct *leader; |
1da177e4 | 173 | int zap_leader; |
1f09f974 | 174 | repeat: |
dae33574 | 175 | tracehook_prepare_release_task(p); |
c69e8d9c DH |
176 | /* don't need to get the RCU readlock here - the process is dead and |
177 | * can't be modifying its own credentials */ | |
178 | atomic_dec(&__task_cred(p)->user->processes); | |
179 | ||
60347f67 | 180 | proc_flush_task(p); |
0203026b | 181 | |
1da177e4 | 182 | write_lock_irq(&tasklist_lock); |
dae33574 | 183 | tracehook_finish_release_task(p); |
1da177e4 | 184 | __exit_signal(p); |
35f5cad8 | 185 | |
1da177e4 LT |
186 | /* |
187 | * If we are the last non-leader member of the thread | |
188 | * group, and the leader is zombie, then notify the | |
189 | * group leader's parent process. (if it wants notification.) | |
190 | */ | |
191 | zap_leader = 0; | |
192 | leader = p->group_leader; | |
193 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
d839fd4d | 194 | BUG_ON(task_detached(leader)); |
1da177e4 LT |
195 | do_notify_parent(leader, leader->exit_signal); |
196 | /* | |
197 | * If we were the last child thread and the leader has | |
198 | * exited already, and the leader's parent ignores SIGCHLD, | |
199 | * then we are the one who should release the leader. | |
200 | * | |
201 | * do_notify_parent() will have marked it self-reaping in | |
202 | * that case. | |
203 | */ | |
d839fd4d | 204 | zap_leader = task_detached(leader); |
dae33574 RM |
205 | |
206 | /* | |
207 | * This maintains the invariant that release_task() | |
208 | * only runs on a task in EXIT_DEAD, just for sanity. | |
209 | */ | |
210 | if (zap_leader) | |
211 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
212 | } |
213 | ||
1da177e4 | 214 | write_unlock_irq(&tasklist_lock); |
1da177e4 | 215 | release_thread(p); |
8c7904a0 | 216 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
217 | |
218 | p = leader; | |
219 | if (unlikely(zap_leader)) | |
220 | goto repeat; | |
221 | } | |
222 | ||
1da177e4 LT |
223 | /* |
224 | * This checks not only the pgrp, but falls back on the pid if no | |
225 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
226 | * without this... | |
04a2e6a5 EB |
227 | * |
228 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 229 | */ |
04a2e6a5 | 230 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
231 | { |
232 | struct task_struct *p; | |
04a2e6a5 | 233 | struct pid *sid = NULL; |
62dfb554 | 234 | |
04a2e6a5 | 235 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 236 | if (p == NULL) |
04a2e6a5 | 237 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 238 | if (p != NULL) |
04a2e6a5 | 239 | sid = task_session(p); |
62dfb554 | 240 | |
1da177e4 LT |
241 | return sid; |
242 | } | |
243 | ||
244 | /* | |
245 | * Determine if a process group is "orphaned", according to the POSIX | |
246 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
247 | * by terminal-generated stop signals. Newly orphaned process groups are | |
248 | * to receive a SIGHUP and a SIGCONT. | |
249 | * | |
250 | * "I ask you, have you ever known what it is to be an orphan?" | |
251 | */ | |
0475ac08 | 252 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
253 | { |
254 | struct task_struct *p; | |
1da177e4 | 255 | |
0475ac08 | 256 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
05e83df6 ON |
257 | if ((p == ignored_task) || |
258 | (p->exit_state && thread_group_empty(p)) || | |
259 | is_global_init(p->real_parent)) | |
1da177e4 | 260 | continue; |
05e83df6 | 261 | |
0475ac08 | 262 | if (task_pgrp(p->real_parent) != pgrp && |
05e83df6 ON |
263 | task_session(p->real_parent) == task_session(p)) |
264 | return 0; | |
0475ac08 | 265 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
05e83df6 ON |
266 | |
267 | return 1; | |
1da177e4 LT |
268 | } |
269 | ||
3e7cd6c4 | 270 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
271 | { |
272 | int retval; | |
273 | ||
274 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 275 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
276 | read_unlock(&tasklist_lock); |
277 | ||
278 | return retval; | |
279 | } | |
280 | ||
0475ac08 | 281 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
282 | { |
283 | int retval = 0; | |
284 | struct task_struct *p; | |
285 | ||
0475ac08 | 286 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
338077e5 | 287 | if (!task_is_stopped(p)) |
1da177e4 | 288 | continue; |
1da177e4 LT |
289 | retval = 1; |
290 | break; | |
0475ac08 | 291 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
292 | return retval; |
293 | } | |
294 | ||
f49ee505 ON |
295 | /* |
296 | * Check to see if any process groups have become orphaned as | |
297 | * a result of our exiting, and if they have any stopped jobs, | |
298 | * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
299 | */ | |
300 | static void | |
301 | kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) | |
302 | { | |
303 | struct pid *pgrp = task_pgrp(tsk); | |
304 | struct task_struct *ignored_task = tsk; | |
305 | ||
306 | if (!parent) | |
307 | /* exit: our father is in a different pgrp than | |
308 | * we are and we were the only connection outside. | |
309 | */ | |
310 | parent = tsk->real_parent; | |
311 | else | |
312 | /* reparent: our child is in a different pgrp than | |
313 | * we are, and it was the only connection outside. | |
314 | */ | |
315 | ignored_task = NULL; | |
316 | ||
317 | if (task_pgrp(parent) != pgrp && | |
318 | task_session(parent) == task_session(tsk) && | |
319 | will_become_orphaned_pgrp(pgrp, ignored_task) && | |
320 | has_stopped_jobs(pgrp)) { | |
321 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
322 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
323 | } | |
324 | } | |
325 | ||
1da177e4 | 326 | /** |
49d769d5 | 327 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
328 | * |
329 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
330 | * it ever exits, it should generally reparent itself to kthreadd so it |
331 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
332 | * |
333 | * The various task state such as scheduling policy and priority may have | |
334 | * been inherited from a user process, so we reset them to sane values here. | |
335 | * | |
49d769d5 | 336 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 337 | */ |
49d769d5 | 338 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
339 | { |
340 | write_lock_irq(&tasklist_lock); | |
341 | ||
342 | ptrace_unlink(current); | |
343 | /* Reparent to init */ | |
49d769d5 | 344 | current->real_parent = current->parent = kthreadd_task; |
f470021a | 345 | list_move_tail(¤t->sibling, ¤t->real_parent->children); |
1da177e4 LT |
346 | |
347 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
348 | current->exit_signal = SIGCHLD; | |
349 | ||
e05606d3 | 350 | if (task_nice(current) < 0) |
1da177e4 LT |
351 | set_user_nice(current, 0); |
352 | /* cpus_allowed? */ | |
353 | /* rt_priority? */ | |
354 | /* signals? */ | |
1da177e4 LT |
355 | memcpy(current->signal->rlim, init_task.signal->rlim, |
356 | sizeof(current->signal->rlim)); | |
d84f4f99 DH |
357 | |
358 | atomic_inc(&init_cred.usage); | |
359 | commit_creds(&init_cred); | |
1da177e4 | 360 | write_unlock_irq(&tasklist_lock); |
1da177e4 LT |
361 | } |
362 | ||
8520d7c7 | 363 | void __set_special_pids(struct pid *pid) |
1da177e4 | 364 | { |
e19f247a | 365 | struct task_struct *curr = current->group_leader; |
1da177e4 | 366 | |
1b0f7ffd | 367 | if (task_session(curr) != pid) |
7d8da096 | 368 | change_pid(curr, PIDTYPE_SID, pid); |
1b0f7ffd ON |
369 | |
370 | if (task_pgrp(curr) != pid) | |
7d8da096 | 371 | change_pid(curr, PIDTYPE_PGID, pid); |
1da177e4 LT |
372 | } |
373 | ||
8520d7c7 | 374 | static void set_special_pids(struct pid *pid) |
1da177e4 LT |
375 | { |
376 | write_lock_irq(&tasklist_lock); | |
8520d7c7 | 377 | __set_special_pids(pid); |
1da177e4 LT |
378 | write_unlock_irq(&tasklist_lock); |
379 | } | |
380 | ||
381 | /* | |
382 | * Let kernel threads use this to say that they | |
383 | * allow a certain signal (since daemonize() will | |
384 | * have disabled all of them by default). | |
385 | */ | |
386 | int allow_signal(int sig) | |
387 | { | |
7ed20e1a | 388 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
389 | return -EINVAL; |
390 | ||
391 | spin_lock_irq(¤t->sighand->siglock); | |
392 | sigdelset(¤t->blocked, sig); | |
393 | if (!current->mm) { | |
394 | /* Kernel threads handle their own signals. | |
395 | Let the signal code know it'll be handled, so | |
396 | that they don't get converted to SIGKILL or | |
397 | just silently dropped */ | |
398 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
399 | } | |
400 | recalc_sigpending(); | |
401 | spin_unlock_irq(¤t->sighand->siglock); | |
402 | return 0; | |
403 | } | |
404 | ||
405 | EXPORT_SYMBOL(allow_signal); | |
406 | ||
407 | int disallow_signal(int sig) | |
408 | { | |
7ed20e1a | 409 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
410 | return -EINVAL; |
411 | ||
412 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 413 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
414 | recalc_sigpending(); |
415 | spin_unlock_irq(¤t->sighand->siglock); | |
416 | return 0; | |
417 | } | |
418 | ||
419 | EXPORT_SYMBOL(disallow_signal); | |
420 | ||
421 | /* | |
422 | * Put all the gunge required to become a kernel thread without | |
423 | * attached user resources in one place where it belongs. | |
424 | */ | |
425 | ||
426 | void daemonize(const char *name, ...) | |
427 | { | |
428 | va_list args; | |
1da177e4 LT |
429 | sigset_t blocked; |
430 | ||
431 | va_start(args, name); | |
432 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
433 | va_end(args); | |
434 | ||
435 | /* | |
436 | * If we were started as result of loading a module, close all of the | |
437 | * user space pages. We don't need them, and if we didn't close them | |
438 | * they would be locked into memory. | |
439 | */ | |
440 | exit_mm(current); | |
83144186 RW |
441 | /* |
442 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
443 | * or suspend transition begins right now. | |
444 | */ | |
7b34e428 | 445 | current->flags |= (PF_NOFREEZE | PF_KTHREAD); |
1da177e4 | 446 | |
8520d7c7 ON |
447 | if (current->nsproxy != &init_nsproxy) { |
448 | get_nsproxy(&init_nsproxy); | |
449 | switch_task_namespaces(current, &init_nsproxy); | |
450 | } | |
297bd42b | 451 | set_special_pids(&init_struct_pid); |
24ec839c | 452 | proc_clear_tty(current); |
1da177e4 LT |
453 | |
454 | /* Block and flush all signals */ | |
455 | sigfillset(&blocked); | |
456 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
457 | flush_signals(current); | |
458 | ||
459 | /* Become as one with the init task */ | |
460 | ||
3e93cd67 | 461 | daemonize_fs_struct(); |
d4c5e41f | 462 | exit_files(current); |
1da177e4 LT |
463 | current->files = init_task.files; |
464 | atomic_inc(¤t->files->count); | |
465 | ||
49d769d5 | 466 | reparent_to_kthreadd(); |
1da177e4 LT |
467 | } |
468 | ||
469 | EXPORT_SYMBOL(daemonize); | |
470 | ||
858119e1 | 471 | static void close_files(struct files_struct * files) |
1da177e4 LT |
472 | { |
473 | int i, j; | |
badf1662 | 474 | struct fdtable *fdt; |
1da177e4 LT |
475 | |
476 | j = 0; | |
4fb3a538 DS |
477 | |
478 | /* | |
479 | * It is safe to dereference the fd table without RCU or | |
480 | * ->file_lock because this is the last reference to the | |
481 | * files structure. | |
482 | */ | |
badf1662 | 483 | fdt = files_fdtable(files); |
1da177e4 LT |
484 | for (;;) { |
485 | unsigned long set; | |
486 | i = j * __NFDBITS; | |
bbea9f69 | 487 | if (i >= fdt->max_fds) |
1da177e4 | 488 | break; |
badf1662 | 489 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
490 | while (set) { |
491 | if (set & 1) { | |
badf1662 | 492 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 493 | if (file) { |
1da177e4 | 494 | filp_close(file, files); |
944be0b2 IM |
495 | cond_resched(); |
496 | } | |
1da177e4 LT |
497 | } |
498 | i++; | |
499 | set >>= 1; | |
500 | } | |
501 | } | |
502 | } | |
503 | ||
504 | struct files_struct *get_files_struct(struct task_struct *task) | |
505 | { | |
506 | struct files_struct *files; | |
507 | ||
508 | task_lock(task); | |
509 | files = task->files; | |
510 | if (files) | |
511 | atomic_inc(&files->count); | |
512 | task_unlock(task); | |
513 | ||
514 | return files; | |
515 | } | |
516 | ||
7ad5b3a5 | 517 | void put_files_struct(struct files_struct *files) |
1da177e4 | 518 | { |
badf1662 DS |
519 | struct fdtable *fdt; |
520 | ||
1da177e4 LT |
521 | if (atomic_dec_and_test(&files->count)) { |
522 | close_files(files); | |
523 | /* | |
524 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
525 | * If the fdtable was embedded, pass files for freeing |
526 | * at the end of the RCU grace period. Otherwise, | |
527 | * you can free files immediately. | |
1da177e4 | 528 | */ |
badf1662 | 529 | fdt = files_fdtable(files); |
4fd45812 | 530 | if (fdt != &files->fdtab) |
ab2af1f5 | 531 | kmem_cache_free(files_cachep, files); |
01b2d93c | 532 | free_fdtable(fdt); |
1da177e4 LT |
533 | } |
534 | } | |
535 | ||
3b125388 | 536 | void reset_files_struct(struct files_struct *files) |
3b9b8ab6 | 537 | { |
3b125388 | 538 | struct task_struct *tsk = current; |
3b9b8ab6 KK |
539 | struct files_struct *old; |
540 | ||
541 | old = tsk->files; | |
542 | task_lock(tsk); | |
543 | tsk->files = files; | |
544 | task_unlock(tsk); | |
545 | put_files_struct(old); | |
546 | } | |
3b9b8ab6 | 547 | |
1ec7f1dd | 548 | void exit_files(struct task_struct *tsk) |
1da177e4 LT |
549 | { |
550 | struct files_struct * files = tsk->files; | |
551 | ||
552 | if (files) { | |
553 | task_lock(tsk); | |
554 | tsk->files = NULL; | |
555 | task_unlock(tsk); | |
556 | put_files_struct(files); | |
557 | } | |
558 | } | |
559 | ||
cf475ad2 BS |
560 | #ifdef CONFIG_MM_OWNER |
561 | /* | |
562 | * Task p is exiting and it owned mm, lets find a new owner for it | |
563 | */ | |
564 | static inline int | |
565 | mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) | |
566 | { | |
567 | /* | |
568 | * If there are other users of the mm and the owner (us) is exiting | |
569 | * we need to find a new owner to take on the responsibility. | |
570 | */ | |
cf475ad2 BS |
571 | if (atomic_read(&mm->mm_users) <= 1) |
572 | return 0; | |
573 | if (mm->owner != p) | |
574 | return 0; | |
575 | return 1; | |
576 | } | |
577 | ||
578 | void mm_update_next_owner(struct mm_struct *mm) | |
579 | { | |
580 | struct task_struct *c, *g, *p = current; | |
581 | ||
582 | retry: | |
583 | if (!mm_need_new_owner(mm, p)) | |
584 | return; | |
585 | ||
586 | read_lock(&tasklist_lock); | |
587 | /* | |
588 | * Search in the children | |
589 | */ | |
590 | list_for_each_entry(c, &p->children, sibling) { | |
591 | if (c->mm == mm) | |
592 | goto assign_new_owner; | |
593 | } | |
594 | ||
595 | /* | |
596 | * Search in the siblings | |
597 | */ | |
598 | list_for_each_entry(c, &p->parent->children, sibling) { | |
599 | if (c->mm == mm) | |
600 | goto assign_new_owner; | |
601 | } | |
602 | ||
603 | /* | |
604 | * Search through everything else. We should not get | |
605 | * here often | |
606 | */ | |
607 | do_each_thread(g, c) { | |
608 | if (c->mm == mm) | |
609 | goto assign_new_owner; | |
610 | } while_each_thread(g, c); | |
611 | ||
612 | read_unlock(&tasklist_lock); | |
31a78f23 BS |
613 | /* |
614 | * We found no owner yet mm_users > 1: this implies that we are | |
615 | * most likely racing with swapoff (try_to_unuse()) or /proc or | |
e5991371 | 616 | * ptrace or page migration (get_task_mm()). Mark owner as NULL. |
31a78f23 | 617 | */ |
31a78f23 | 618 | mm->owner = NULL; |
cf475ad2 BS |
619 | return; |
620 | ||
621 | assign_new_owner: | |
622 | BUG_ON(c == p); | |
623 | get_task_struct(c); | |
624 | /* | |
625 | * The task_lock protects c->mm from changing. | |
626 | * We always want mm->owner->mm == mm | |
627 | */ | |
628 | task_lock(c); | |
e5991371 HD |
629 | /* |
630 | * Delay read_unlock() till we have the task_lock() | |
631 | * to ensure that c does not slip away underneath us | |
632 | */ | |
633 | read_unlock(&tasklist_lock); | |
cf475ad2 BS |
634 | if (c->mm != mm) { |
635 | task_unlock(c); | |
636 | put_task_struct(c); | |
637 | goto retry; | |
638 | } | |
cf475ad2 BS |
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; | |
b564daf8 | 652 | struct core_state *core_state; |
1da177e4 LT |
653 | |
654 | mm_release(tsk, mm); | |
655 | if (!mm) | |
656 | return; | |
657 | /* | |
658 | * Serialize with any possible pending coredump. | |
999d9fc1 | 659 | * We must hold mmap_sem around checking core_state |
1da177e4 | 660 | * and clearing tsk->mm. The core-inducing thread |
999d9fc1 | 661 | * will increment ->nr_threads for each thread in the |
1da177e4 LT |
662 | * group with ->mm != NULL. |
663 | */ | |
664 | down_read(&mm->mmap_sem); | |
b564daf8 ON |
665 | core_state = mm->core_state; |
666 | if (core_state) { | |
667 | struct core_thread self; | |
1da177e4 | 668 | up_read(&mm->mmap_sem); |
c5f1cc8c | 669 | |
b564daf8 ON |
670 | self.task = tsk; |
671 | self.next = xchg(&core_state->dumper.next, &self); | |
672 | /* | |
673 | * Implies mb(), the result of xchg() must be visible | |
674 | * to core_state->dumper. | |
675 | */ | |
676 | if (atomic_dec_and_test(&core_state->nr_threads)) | |
677 | complete(&core_state->startup); | |
1da177e4 | 678 | |
a94e2d40 ON |
679 | for (;;) { |
680 | set_task_state(tsk, TASK_UNINTERRUPTIBLE); | |
681 | if (!self.task) /* see coredump_finish() */ | |
682 | break; | |
683 | schedule(); | |
684 | } | |
685 | __set_task_state(tsk, TASK_RUNNING); | |
1da177e4 LT |
686 | down_read(&mm->mmap_sem); |
687 | } | |
688 | atomic_inc(&mm->mm_count); | |
125e1874 | 689 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
690 | /* more a memory barrier than a real lock */ |
691 | task_lock(tsk); | |
692 | tsk->mm = NULL; | |
693 | up_read(&mm->mmap_sem); | |
694 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
695 | /* We don't want this task to be frozen prematurely */ |
696 | clear_freeze_flag(tsk); | |
1da177e4 | 697 | task_unlock(tsk); |
cf475ad2 | 698 | mm_update_next_owner(mm); |
1da177e4 LT |
699 | mmput(mm); |
700 | } | |
701 | ||
1da177e4 LT |
702 | /* |
703 | * When we die, we re-parent all our children. | |
704 | * Try to give them to another thread in our thread | |
705 | * group, and if no such member exists, give it to | |
84d73786 SB |
706 | * the child reaper process (ie "init") in our pid |
707 | * space. | |
1da177e4 | 708 | */ |
950bbabb ON |
709 | static struct task_struct *find_new_reaper(struct task_struct *father) |
710 | { | |
711 | struct pid_namespace *pid_ns = task_active_pid_ns(father); | |
712 | struct task_struct *thread; | |
713 | ||
714 | thread = father; | |
715 | while_each_thread(father, thread) { | |
716 | if (thread->flags & PF_EXITING) | |
717 | continue; | |
718 | if (unlikely(pid_ns->child_reaper == father)) | |
719 | pid_ns->child_reaper = thread; | |
720 | return thread; | |
721 | } | |
722 | ||
723 | if (unlikely(pid_ns->child_reaper == father)) { | |
724 | write_unlock_irq(&tasklist_lock); | |
725 | if (unlikely(pid_ns == &init_pid_ns)) | |
726 | panic("Attempted to kill init!"); | |
727 | ||
728 | zap_pid_ns_processes(pid_ns); | |
729 | write_lock_irq(&tasklist_lock); | |
730 | /* | |
731 | * We can not clear ->child_reaper or leave it alone. | |
732 | * There may by stealth EXIT_DEAD tasks on ->children, | |
733 | * forget_original_parent() must move them somewhere. | |
734 | */ | |
735 | pid_ns->child_reaper = init_pid_ns.child_reaper; | |
736 | } | |
737 | ||
738 | return pid_ns->child_reaper; | |
739 | } | |
740 | ||
5dfc80be ON |
741 | /* |
742 | * Any that need to be release_task'd are put on the @dead list. | |
743 | */ | |
744 | static void reparent_thread(struct task_struct *father, struct task_struct *p, | |
745 | struct list_head *dead) | |
746 | { | |
747 | if (p->pdeath_signal) | |
748 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
749 | ||
750 | list_move_tail(&p->sibling, &p->real_parent->children); | |
751 | ||
752 | if (task_detached(p)) | |
753 | return; | |
754 | /* | |
755 | * If this is a threaded reparent there is no need to | |
756 | * notify anyone anything has happened. | |
757 | */ | |
758 | if (same_thread_group(p->real_parent, father)) | |
759 | return; | |
760 | ||
761 | /* We don't want people slaying init. */ | |
762 | p->exit_signal = SIGCHLD; | |
763 | ||
764 | /* If it has exited notify the new parent about this child's death. */ | |
765 | if (!p->ptrace && | |
766 | p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) { | |
767 | do_notify_parent(p, p->exit_signal); | |
768 | if (task_detached(p)) { | |
769 | p->exit_state = EXIT_DEAD; | |
770 | list_move_tail(&p->sibling, dead); | |
771 | } | |
772 | } | |
773 | ||
774 | kill_orphaned_pgrp(p, father); | |
775 | } | |
776 | ||
762a24be | 777 | static void forget_original_parent(struct task_struct *father) |
1da177e4 | 778 | { |
950bbabb | 779 | struct task_struct *p, *n, *reaper; |
5dfc80be | 780 | LIST_HEAD(dead_children); |
762a24be | 781 | |
39c626ae | 782 | exit_ptrace(father); |
762a24be ON |
783 | |
784 | write_lock_irq(&tasklist_lock); | |
950bbabb | 785 | reaper = find_new_reaper(father); |
f470021a | 786 | |
03ff1797 | 787 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
84eb646b | 788 | p->real_parent = reaper; |
f470021a RM |
789 | if (p->parent == father) { |
790 | BUG_ON(p->ptrace); | |
791 | p->parent = p->real_parent; | |
792 | } | |
5dfc80be | 793 | reparent_thread(father, p, &dead_children); |
1da177e4 | 794 | } |
762a24be | 795 | write_unlock_irq(&tasklist_lock); |
5dfc80be | 796 | |
762a24be | 797 | BUG_ON(!list_empty(&father->children)); |
762a24be | 798 | |
5dfc80be ON |
799 | list_for_each_entry_safe(p, n, &dead_children, sibling) { |
800 | list_del_init(&p->sibling); | |
39c626ae ON |
801 | release_task(p); |
802 | } | |
1da177e4 LT |
803 | } |
804 | ||
805 | /* | |
806 | * Send signals to all our closest relatives so that they know | |
807 | * to properly mourn us.. | |
808 | */ | |
821c7de7 | 809 | static void exit_notify(struct task_struct *tsk, int group_dead) |
1da177e4 | 810 | { |
2b2a1ff6 RM |
811 | int signal; |
812 | void *cookie; | |
1da177e4 | 813 | |
1da177e4 LT |
814 | /* |
815 | * This does two things: | |
816 | * | |
817 | * A. Make init inherit all the child processes | |
818 | * B. Check to see if any process groups have become orphaned | |
819 | * as a result of our exiting, and if they have any stopped | |
820 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
821 | */ | |
762a24be | 822 | forget_original_parent(tsk); |
2e4a7072 | 823 | exit_task_namespaces(tsk); |
1da177e4 | 824 | |
762a24be | 825 | write_lock_irq(&tasklist_lock); |
821c7de7 ON |
826 | if (group_dead) |
827 | kill_orphaned_pgrp(tsk->group_leader, NULL); | |
1da177e4 | 828 | |
24728448 | 829 | /* Let father know we died |
1da177e4 LT |
830 | * |
831 | * Thread signals are configurable, but you aren't going to use | |
d4c5e41f | 832 | * that to send signals to arbitary processes. |
1da177e4 LT |
833 | * That stops right now. |
834 | * | |
835 | * If the parent exec id doesn't match the exec id we saved | |
836 | * when we started then we know the parent has changed security | |
837 | * domain. | |
838 | * | |
839 | * If our self_exec id doesn't match our parent_exec_id then | |
840 | * we have changed execution domain as these two values started | |
841 | * the same after a fork. | |
1da177e4 | 842 | */ |
d839fd4d | 843 | if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) && |
f49ee505 | 844 | (tsk->parent_exec_id != tsk->real_parent->self_exec_id || |
432870da | 845 | tsk->self_exec_id != tsk->parent_exec_id)) |
1da177e4 LT |
846 | tsk->exit_signal = SIGCHLD; |
847 | ||
2b2a1ff6 | 848 | signal = tracehook_notify_death(tsk, &cookie, group_dead); |
5c7edcd7 | 849 | if (signal >= 0) |
2b2a1ff6 | 850 | signal = do_notify_parent(tsk, signal); |
1da177e4 | 851 | |
5c7edcd7 | 852 | tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE; |
1da177e4 | 853 | |
2800d8d1 | 854 | /* mt-exec, de_thread() is waiting for us */ |
6db840fa | 855 | if (thread_group_leader(tsk) && |
2633f0e5 SV |
856 | tsk->signal->group_exit_task && |
857 | tsk->signal->notify_count < 0) | |
6db840fa ON |
858 | wake_up_process(tsk->signal->group_exit_task); |
859 | ||
1da177e4 LT |
860 | write_unlock_irq(&tasklist_lock); |
861 | ||
2b2a1ff6 RM |
862 | tracehook_report_death(tsk, signal, cookie, group_dead); |
863 | ||
1da177e4 | 864 | /* If the process is dead, release it - nobody will wait for it */ |
5c7edcd7 | 865 | if (signal == DEATH_REAP) |
1da177e4 | 866 | release_task(tsk); |
1da177e4 LT |
867 | } |
868 | ||
e18eecb8 JD |
869 | #ifdef CONFIG_DEBUG_STACK_USAGE |
870 | static void check_stack_usage(void) | |
871 | { | |
872 | static DEFINE_SPINLOCK(low_water_lock); | |
873 | static int lowest_to_date = THREAD_SIZE; | |
e18eecb8 JD |
874 | unsigned long free; |
875 | ||
7c9f8861 | 876 | free = stack_not_used(current); |
e18eecb8 JD |
877 | |
878 | if (free >= lowest_to_date) | |
879 | return; | |
880 | ||
881 | spin_lock(&low_water_lock); | |
882 | if (free < lowest_to_date) { | |
883 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
884 | "left\n", | |
885 | current->comm, free); | |
886 | lowest_to_date = free; | |
887 | } | |
888 | spin_unlock(&low_water_lock); | |
889 | } | |
890 | #else | |
891 | static inline void check_stack_usage(void) {} | |
892 | #endif | |
893 | ||
7ad5b3a5 | 894 | NORET_TYPE void do_exit(long code) |
1da177e4 LT |
895 | { |
896 | struct task_struct *tsk = current; | |
897 | int group_dead; | |
898 | ||
899 | profile_task_exit(tsk); | |
900 | ||
22e2c507 JA |
901 | WARN_ON(atomic_read(&tsk->fs_excl)); |
902 | ||
1da177e4 LT |
903 | if (unlikely(in_interrupt())) |
904 | panic("Aiee, killing interrupt handler!"); | |
905 | if (unlikely(!tsk->pid)) | |
906 | panic("Attempted to kill the idle task!"); | |
1da177e4 | 907 | |
30199f5a | 908 | tracehook_report_exit(&code); |
1da177e4 | 909 | |
df164db5 AN |
910 | /* |
911 | * We're taking recursive faults here in do_exit. Safest is to just | |
912 | * leave this task alone and wait for reboot. | |
913 | */ | |
914 | if (unlikely(tsk->flags & PF_EXITING)) { | |
915 | printk(KERN_ALERT | |
916 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
917 | /* |
918 | * We can do this unlocked here. The futex code uses | |
919 | * this flag just to verify whether the pi state | |
920 | * cleanup has been done or not. In the worst case it | |
921 | * loops once more. We pretend that the cleanup was | |
922 | * done as there is no way to return. Either the | |
923 | * OWNER_DIED bit is set by now or we push the blocked | |
924 | * task into the wait for ever nirwana as well. | |
925 | */ | |
926 | tsk->flags |= PF_EXITPIDONE; | |
df164db5 AN |
927 | set_current_state(TASK_UNINTERRUPTIBLE); |
928 | schedule(); | |
929 | } | |
930 | ||
3aa551c9 TG |
931 | exit_irq_thread(); |
932 | ||
d12619b5 | 933 | exit_signals(tsk); /* sets PF_EXITING */ |
778e9a9c AK |
934 | /* |
935 | * tsk->flags are checked in the futex code to protect against | |
936 | * an exiting task cleaning up the robust pi futexes. | |
937 | */ | |
d2ee7198 ON |
938 | smp_mb(); |
939 | spin_unlock_wait(&tsk->pi_lock); | |
1da177e4 | 940 | |
1da177e4 LT |
941 | if (unlikely(in_atomic())) |
942 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
ba25f9dc | 943 | current->comm, task_pid_nr(current), |
1da177e4 LT |
944 | preempt_count()); |
945 | ||
946 | acct_update_integrals(tsk); | |
901608d9 | 947 | |
1da177e4 | 948 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 949 | if (group_dead) { |
778e9a9c | 950 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 951 | exit_itimers(tsk->signal); |
c3068951 | 952 | } |
f6ec29a4 | 953 | acct_collect(code, group_dead); |
522ed776 MT |
954 | if (group_dead) |
955 | tty_audit_exit(); | |
fa84cb93 AV |
956 | if (unlikely(tsk->audit_context)) |
957 | audit_free(tsk); | |
115085ea | 958 | |
f2ab6d88 | 959 | tsk->exit_code = code; |
115085ea | 960 | taskstats_exit(tsk, group_dead); |
c757249a | 961 | |
1da177e4 LT |
962 | exit_mm(tsk); |
963 | ||
0e464814 | 964 | if (group_dead) |
f6ec29a4 | 965 | acct_process(); |
0a16b607 MD |
966 | trace_sched_process_exit(tsk); |
967 | ||
1da177e4 | 968 | exit_sem(tsk); |
1ec7f1dd AV |
969 | exit_files(tsk); |
970 | exit_fs(tsk); | |
e18eecb8 | 971 | check_stack_usage(); |
1da177e4 | 972 | exit_thread(); |
b4f48b63 | 973 | cgroup_exit(tsk, 1); |
1da177e4 LT |
974 | |
975 | if (group_dead && tsk->signal->leader) | |
976 | disassociate_ctty(1); | |
977 | ||
a1261f54 | 978 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
979 | if (tsk->binfmt) |
980 | module_put(tsk->binfmt->module); | |
981 | ||
9f46080c | 982 | proc_exit_connector(tsk); |
33b2fb30 IM |
983 | |
984 | /* | |
985 | * Flush inherited counters to the parent - before the parent | |
986 | * gets woken up by child-exit notifications. | |
987 | */ | |
988 | perf_counter_exit_task(tsk); | |
989 | ||
821c7de7 | 990 | exit_notify(tsk, group_dead); |
1da177e4 | 991 | #ifdef CONFIG_NUMA |
f0be3d32 | 992 | mpol_put(tsk->mempolicy); |
1da177e4 LT |
993 | tsk->mempolicy = NULL; |
994 | #endif | |
9b51f66d | 995 | #ifdef CONFIG_FUTEX |
c87e2837 IM |
996 | if (unlikely(!list_empty(&tsk->pi_state_list))) |
997 | exit_pi_state_list(tsk); | |
998 | if (unlikely(current->pi_state_cache)) | |
999 | kfree(current->pi_state_cache); | |
42b2dd0a | 1000 | #endif |
de5097c2 | 1001 | /* |
9a11b49a | 1002 | * Make sure we are holding no locks: |
de5097c2 | 1003 | */ |
9a11b49a | 1004 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1005 | /* |
1006 | * We can do this unlocked here. The futex code uses this flag | |
1007 | * just to verify whether the pi state cleanup has been done | |
1008 | * or not. In the worst case it loops once more. | |
1009 | */ | |
1010 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1011 | |
afc847b7 AV |
1012 | if (tsk->io_context) |
1013 | exit_io_context(); | |
1014 | ||
b92ce558 JA |
1015 | if (tsk->splice_pipe) |
1016 | __free_pipe_info(tsk->splice_pipe); | |
1017 | ||
7407251a | 1018 | preempt_disable(); |
55a101f8 | 1019 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1020 | tsk->state = TASK_DEAD; |
1da177e4 LT |
1021 | schedule(); |
1022 | BUG(); | |
1023 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1024 | for (;;) |
1025 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1026 | } |
1027 | ||
012914da RA |
1028 | EXPORT_SYMBOL_GPL(do_exit); |
1029 | ||
1da177e4 LT |
1030 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1031 | { | |
1032 | if (comp) | |
1033 | complete(comp); | |
55a101f8 | 1034 | |
1da177e4 LT |
1035 | do_exit(code); |
1036 | } | |
1037 | ||
1038 | EXPORT_SYMBOL(complete_and_exit); | |
1039 | ||
754fe8d2 | 1040 | SYSCALL_DEFINE1(exit, int, error_code) |
1da177e4 LT |
1041 | { |
1042 | do_exit((error_code&0xff)<<8); | |
1043 | } | |
1044 | ||
1da177e4 LT |
1045 | /* |
1046 | * Take down every thread in the group. This is called by fatal signals | |
1047 | * as well as by sys_exit_group (below). | |
1048 | */ | |
1049 | NORET_TYPE void | |
1050 | do_group_exit(int exit_code) | |
1051 | { | |
bfc4b089 ON |
1052 | struct signal_struct *sig = current->signal; |
1053 | ||
1da177e4 LT |
1054 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
1055 | ||
bfc4b089 ON |
1056 | if (signal_group_exit(sig)) |
1057 | exit_code = sig->group_exit_code; | |
1da177e4 | 1058 | else if (!thread_group_empty(current)) { |
1da177e4 | 1059 | struct sighand_struct *const sighand = current->sighand; |
1da177e4 | 1060 | spin_lock_irq(&sighand->siglock); |
ed5d2cac | 1061 | if (signal_group_exit(sig)) |
1da177e4 LT |
1062 | /* Another thread got here before we took the lock. */ |
1063 | exit_code = sig->group_exit_code; | |
1064 | else { | |
1da177e4 | 1065 | sig->group_exit_code = exit_code; |
ed5d2cac | 1066 | sig->flags = SIGNAL_GROUP_EXIT; |
1da177e4 LT |
1067 | zap_other_threads(current); |
1068 | } | |
1069 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1070 | } |
1071 | ||
1072 | do_exit(exit_code); | |
1073 | /* NOTREACHED */ | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * this kills every thread in the thread group. Note that any externally | |
1078 | * wait4()-ing process will get the correct exit code - even if this | |
1079 | * thread is not the thread group leader. | |
1080 | */ | |
754fe8d2 | 1081 | SYSCALL_DEFINE1(exit_group, int, error_code) |
1da177e4 LT |
1082 | { |
1083 | do_group_exit((error_code & 0xff) << 8); | |
2ed7c03e HC |
1084 | /* NOTREACHED */ |
1085 | return 0; | |
1da177e4 LT |
1086 | } |
1087 | ||
161550d7 EB |
1088 | static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) |
1089 | { | |
1090 | struct pid *pid = NULL; | |
1091 | if (type == PIDTYPE_PID) | |
1092 | pid = task->pids[type].pid; | |
1093 | else if (type < PIDTYPE_MAX) | |
1094 | pid = task->group_leader->pids[type].pid; | |
1095 | return pid; | |
1096 | } | |
1097 | ||
1098 | static int eligible_child(enum pid_type type, struct pid *pid, int options, | |
1099 | struct task_struct *p) | |
1da177e4 | 1100 | { |
73243284 RM |
1101 | int err; |
1102 | ||
161550d7 EB |
1103 | if (type < PIDTYPE_MAX) { |
1104 | if (task_pid_type(p, type) != pid) | |
1da177e4 LT |
1105 | return 0; |
1106 | } | |
1107 | ||
1da177e4 LT |
1108 | /* Wait for all children (clone and not) if __WALL is set; |
1109 | * otherwise, wait for clone children *only* if __WCLONE is | |
1110 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1111 | * A "clone" child here is one that reports to its parent | |
1112 | * using a signal other than SIGCHLD.) */ | |
1113 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1114 | && !(options & __WALL)) | |
1115 | return 0; | |
1da177e4 | 1116 | |
73243284 | 1117 | err = security_task_wait(p); |
14dd0b81 RM |
1118 | if (err) |
1119 | return err; | |
1da177e4 | 1120 | |
14dd0b81 | 1121 | return 1; |
1da177e4 LT |
1122 | } |
1123 | ||
36c8b586 | 1124 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1125 | int why, int status, |
1126 | struct siginfo __user *infop, | |
1127 | struct rusage __user *rusagep) | |
1128 | { | |
1129 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1130 | |
1da177e4 LT |
1131 | put_task_struct(p); |
1132 | if (!retval) | |
1133 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1134 | if (!retval) | |
1135 | retval = put_user(0, &infop->si_errno); | |
1136 | if (!retval) | |
1137 | retval = put_user((short)why, &infop->si_code); | |
1138 | if (!retval) | |
1139 | retval = put_user(pid, &infop->si_pid); | |
1140 | if (!retval) | |
1141 | retval = put_user(uid, &infop->si_uid); | |
1142 | if (!retval) | |
1143 | retval = put_user(status, &infop->si_status); | |
1144 | if (!retval) | |
1145 | retval = pid; | |
1146 | return retval; | |
1147 | } | |
1148 | ||
1149 | /* | |
1150 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1151 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1152 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1153 | * released the lock and the system call should return. | |
1154 | */ | |
98abed02 | 1155 | static int wait_task_zombie(struct task_struct *p, int options, |
1da177e4 LT |
1156 | struct siginfo __user *infop, |
1157 | int __user *stat_addr, struct rusage __user *ru) | |
1158 | { | |
1159 | unsigned long state; | |
2f4e6e2a | 1160 | int retval, status, traced; |
6c5f3e7b | 1161 | pid_t pid = task_pid_vnr(p); |
c69e8d9c | 1162 | uid_t uid = __task_cred(p)->uid; |
1da177e4 | 1163 | |
98abed02 RM |
1164 | if (!likely(options & WEXITED)) |
1165 | return 0; | |
1166 | ||
1167 | if (unlikely(options & WNOWAIT)) { | |
1da177e4 LT |
1168 | int exit_code = p->exit_code; |
1169 | int why, status; | |
1170 | ||
1da177e4 LT |
1171 | get_task_struct(p); |
1172 | read_unlock(&tasklist_lock); | |
1173 | if ((exit_code & 0x7f) == 0) { | |
1174 | why = CLD_EXITED; | |
1175 | status = exit_code >> 8; | |
1176 | } else { | |
1177 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1178 | status = exit_code & 0x7f; | |
1179 | } | |
1180 | return wait_noreap_copyout(p, pid, uid, why, | |
1181 | status, infop, ru); | |
1182 | } | |
1183 | ||
1184 | /* | |
1185 | * Try to move the task's state to DEAD | |
1186 | * only one thread is allowed to do this: | |
1187 | */ | |
1188 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1189 | if (state != EXIT_ZOMBIE) { | |
1190 | BUG_ON(state != EXIT_DEAD); | |
1191 | return 0; | |
1192 | } | |
1da177e4 | 1193 | |
53b6f9fb | 1194 | traced = ptrace_reparented(p); |
2f4e6e2a ON |
1195 | |
1196 | if (likely(!traced)) { | |
3795e161 JJ |
1197 | struct signal_struct *psig; |
1198 | struct signal_struct *sig; | |
f06febc9 | 1199 | struct task_cputime cputime; |
3795e161 | 1200 | |
1da177e4 LT |
1201 | /* |
1202 | * The resource counters for the group leader are in its | |
1203 | * own task_struct. Those for dead threads in the group | |
1204 | * are in its signal_struct, as are those for the child | |
1205 | * processes it has previously reaped. All these | |
1206 | * accumulate in the parent's signal_struct c* fields. | |
1207 | * | |
1208 | * We don't bother to take a lock here to protect these | |
1209 | * p->signal fields, because they are only touched by | |
1210 | * __exit_signal, which runs with tasklist_lock | |
1211 | * write-locked anyway, and so is excluded here. We do | |
1212 | * need to protect the access to p->parent->signal fields, | |
1213 | * as other threads in the parent group can be right | |
1214 | * here reaping other children at the same time. | |
f06febc9 FM |
1215 | * |
1216 | * We use thread_group_cputime() to get times for the thread | |
1217 | * group, which consolidates times for all threads in the | |
1218 | * group including the group leader. | |
1da177e4 | 1219 | */ |
2b5fe6de | 1220 | thread_group_cputime(p, &cputime); |
1da177e4 | 1221 | spin_lock_irq(&p->parent->sighand->siglock); |
3795e161 JJ |
1222 | psig = p->parent->signal; |
1223 | sig = p->signal; | |
1224 | psig->cutime = | |
1225 | cputime_add(psig->cutime, | |
f06febc9 FM |
1226 | cputime_add(cputime.utime, |
1227 | sig->cutime)); | |
3795e161 JJ |
1228 | psig->cstime = |
1229 | cputime_add(psig->cstime, | |
f06febc9 FM |
1230 | cputime_add(cputime.stime, |
1231 | sig->cstime)); | |
9ac52315 LV |
1232 | psig->cgtime = |
1233 | cputime_add(psig->cgtime, | |
1234 | cputime_add(p->gtime, | |
1235 | cputime_add(sig->gtime, | |
1236 | sig->cgtime))); | |
3795e161 JJ |
1237 | psig->cmin_flt += |
1238 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1239 | psig->cmaj_flt += | |
1240 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1241 | psig->cnvcsw += | |
1242 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1243 | psig->cnivcsw += | |
1244 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1245 | psig->cinblock += |
1246 | task_io_get_inblock(p) + | |
1247 | sig->inblock + sig->cinblock; | |
1248 | psig->coublock += | |
1249 | task_io_get_oublock(p) + | |
1250 | sig->oublock + sig->coublock; | |
5995477a AR |
1251 | task_io_accounting_add(&psig->ioac, &p->ioac); |
1252 | task_io_accounting_add(&psig->ioac, &sig->ioac); | |
1da177e4 LT |
1253 | spin_unlock_irq(&p->parent->sighand->siglock); |
1254 | } | |
1255 | ||
1256 | /* | |
1257 | * Now we are sure this task is interesting, and no other | |
1258 | * thread can reap it because we set its state to EXIT_DEAD. | |
1259 | */ | |
1260 | read_unlock(&tasklist_lock); | |
1261 | ||
1262 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1263 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1264 | ? p->signal->group_exit_code : p->exit_code; | |
1265 | if (!retval && stat_addr) | |
1266 | retval = put_user(status, stat_addr); | |
1267 | if (!retval && infop) | |
1268 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1269 | if (!retval && infop) | |
1270 | retval = put_user(0, &infop->si_errno); | |
1271 | if (!retval && infop) { | |
1272 | int why; | |
1273 | ||
1274 | if ((status & 0x7f) == 0) { | |
1275 | why = CLD_EXITED; | |
1276 | status >>= 8; | |
1277 | } else { | |
1278 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1279 | status &= 0x7f; | |
1280 | } | |
1281 | retval = put_user((short)why, &infop->si_code); | |
1282 | if (!retval) | |
1283 | retval = put_user(status, &infop->si_status); | |
1284 | } | |
1285 | if (!retval && infop) | |
3a515e4a | 1286 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1287 | if (!retval && infop) |
c69e8d9c | 1288 | retval = put_user(uid, &infop->si_uid); |
2f4e6e2a | 1289 | if (!retval) |
3a515e4a | 1290 | retval = pid; |
2f4e6e2a ON |
1291 | |
1292 | if (traced) { | |
1da177e4 | 1293 | write_lock_irq(&tasklist_lock); |
2f4e6e2a ON |
1294 | /* We dropped tasklist, ptracer could die and untrace */ |
1295 | ptrace_unlink(p); | |
1296 | /* | |
1297 | * If this is not a detached task, notify the parent. | |
1298 | * If it's still not detached after that, don't release | |
1299 | * it now. | |
1300 | */ | |
d839fd4d | 1301 | if (!task_detached(p)) { |
2f4e6e2a | 1302 | do_notify_parent(p, p->exit_signal); |
d839fd4d | 1303 | if (!task_detached(p)) { |
2f4e6e2a ON |
1304 | p->exit_state = EXIT_ZOMBIE; |
1305 | p = NULL; | |
1da177e4 LT |
1306 | } |
1307 | } | |
1308 | write_unlock_irq(&tasklist_lock); | |
1309 | } | |
1310 | if (p != NULL) | |
1311 | release_task(p); | |
2f4e6e2a | 1312 | |
1da177e4 LT |
1313 | return retval; |
1314 | } | |
1315 | ||
90bc8d8b ON |
1316 | static int *task_stopped_code(struct task_struct *p, bool ptrace) |
1317 | { | |
1318 | if (ptrace) { | |
1319 | if (task_is_stopped_or_traced(p)) | |
1320 | return &p->exit_code; | |
1321 | } else { | |
1322 | if (p->signal->flags & SIGNAL_STOP_STOPPED) | |
1323 | return &p->signal->group_exit_code; | |
1324 | } | |
1325 | return NULL; | |
1326 | } | |
1327 | ||
1da177e4 LT |
1328 | /* |
1329 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1330 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1331 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1332 | * released the lock and the system call should return. | |
1333 | */ | |
f470021a | 1334 | static int wait_task_stopped(int ptrace, struct task_struct *p, |
98abed02 | 1335 | int options, struct siginfo __user *infop, |
1da177e4 LT |
1336 | int __user *stat_addr, struct rusage __user *ru) |
1337 | { | |
90bc8d8b | 1338 | int retval, exit_code, *p_code, why; |
ee7c82da | 1339 | uid_t uid = 0; /* unneeded, required by compiler */ |
c8950783 | 1340 | pid_t pid; |
1da177e4 | 1341 | |
f470021a | 1342 | if (!(options & WUNTRACED)) |
98abed02 RM |
1343 | return 0; |
1344 | ||
ee7c82da ON |
1345 | exit_code = 0; |
1346 | spin_lock_irq(&p->sighand->siglock); | |
1347 | ||
90bc8d8b ON |
1348 | p_code = task_stopped_code(p, ptrace); |
1349 | if (unlikely(!p_code)) | |
ee7c82da ON |
1350 | goto unlock_sig; |
1351 | ||
90bc8d8b | 1352 | exit_code = *p_code; |
ee7c82da ON |
1353 | if (!exit_code) |
1354 | goto unlock_sig; | |
1355 | ||
98abed02 | 1356 | if (!unlikely(options & WNOWAIT)) |
90bc8d8b | 1357 | *p_code = 0; |
ee7c82da | 1358 | |
c69e8d9c DH |
1359 | /* don't need the RCU readlock here as we're holding a spinlock */ |
1360 | uid = __task_cred(p)->uid; | |
ee7c82da ON |
1361 | unlock_sig: |
1362 | spin_unlock_irq(&p->sighand->siglock); | |
1363 | if (!exit_code) | |
1da177e4 LT |
1364 | return 0; |
1365 | ||
1366 | /* | |
1367 | * Now we are pretty sure this task is interesting. | |
1368 | * Make sure it doesn't get reaped out from under us while we | |
1369 | * give up the lock and then examine it below. We don't want to | |
1370 | * keep holding onto the tasklist_lock while we call getrusage and | |
1371 | * possibly take page faults for user memory. | |
1372 | */ | |
1373 | get_task_struct(p); | |
6c5f3e7b | 1374 | pid = task_pid_vnr(p); |
f470021a | 1375 | why = ptrace ? CLD_TRAPPED : CLD_STOPPED; |
1da177e4 LT |
1376 | read_unlock(&tasklist_lock); |
1377 | ||
98abed02 | 1378 | if (unlikely(options & WNOWAIT)) |
1da177e4 | 1379 | return wait_noreap_copyout(p, pid, uid, |
e6ceb32a | 1380 | why, exit_code, |
1da177e4 | 1381 | infop, ru); |
1da177e4 LT |
1382 | |
1383 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1384 | if (!retval && stat_addr) | |
1385 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1386 | if (!retval && infop) | |
1387 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1388 | if (!retval && infop) | |
1389 | retval = put_user(0, &infop->si_errno); | |
1390 | if (!retval && infop) | |
6efcae46 | 1391 | retval = put_user((short)why, &infop->si_code); |
1da177e4 LT |
1392 | if (!retval && infop) |
1393 | retval = put_user(exit_code, &infop->si_status); | |
1394 | if (!retval && infop) | |
c8950783 | 1395 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1396 | if (!retval && infop) |
ee7c82da | 1397 | retval = put_user(uid, &infop->si_uid); |
1da177e4 | 1398 | if (!retval) |
c8950783 | 1399 | retval = pid; |
1da177e4 LT |
1400 | put_task_struct(p); |
1401 | ||
1402 | BUG_ON(!retval); | |
1403 | return retval; | |
1404 | } | |
1405 | ||
1406 | /* | |
1407 | * Handle do_wait work for one task in a live, non-stopped state. | |
1408 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1409 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1410 | * released the lock and the system call should return. | |
1411 | */ | |
98abed02 | 1412 | static int wait_task_continued(struct task_struct *p, int options, |
1da177e4 LT |
1413 | struct siginfo __user *infop, |
1414 | int __user *stat_addr, struct rusage __user *ru) | |
1415 | { | |
1416 | int retval; | |
1417 | pid_t pid; | |
1418 | uid_t uid; | |
1419 | ||
98abed02 RM |
1420 | if (!unlikely(options & WCONTINUED)) |
1421 | return 0; | |
1422 | ||
1da177e4 LT |
1423 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
1424 | return 0; | |
1425 | ||
1426 | spin_lock_irq(&p->sighand->siglock); | |
1427 | /* Re-check with the lock held. */ | |
1428 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1429 | spin_unlock_irq(&p->sighand->siglock); | |
1430 | return 0; | |
1431 | } | |
98abed02 | 1432 | if (!unlikely(options & WNOWAIT)) |
1da177e4 | 1433 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; |
c69e8d9c | 1434 | uid = __task_cred(p)->uid; |
1da177e4 LT |
1435 | spin_unlock_irq(&p->sighand->siglock); |
1436 | ||
6c5f3e7b | 1437 | pid = task_pid_vnr(p); |
1da177e4 LT |
1438 | get_task_struct(p); |
1439 | read_unlock(&tasklist_lock); | |
1440 | ||
1441 | if (!infop) { | |
1442 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1443 | put_task_struct(p); | |
1444 | if (!retval && stat_addr) | |
1445 | retval = put_user(0xffff, stat_addr); | |
1446 | if (!retval) | |
3a515e4a | 1447 | retval = pid; |
1da177e4 LT |
1448 | } else { |
1449 | retval = wait_noreap_copyout(p, pid, uid, | |
1450 | CLD_CONTINUED, SIGCONT, | |
1451 | infop, ru); | |
1452 | BUG_ON(retval == 0); | |
1453 | } | |
1454 | ||
1455 | return retval; | |
1456 | } | |
1457 | ||
98abed02 RM |
1458 | /* |
1459 | * Consider @p for a wait by @parent. | |
1460 | * | |
1461 | * -ECHILD should be in *@notask_error before the first call. | |
1462 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1463 | * Returns zero if the search for a child should continue; | |
14dd0b81 RM |
1464 | * then *@notask_error is 0 if @p is an eligible child, |
1465 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 | 1466 | */ |
f470021a | 1467 | static int wait_consider_task(struct task_struct *parent, int ptrace, |
98abed02 RM |
1468 | struct task_struct *p, int *notask_error, |
1469 | enum pid_type type, struct pid *pid, int options, | |
1470 | struct siginfo __user *infop, | |
1471 | int __user *stat_addr, struct rusage __user *ru) | |
1472 | { | |
1473 | int ret = eligible_child(type, pid, options, p); | |
14dd0b81 | 1474 | if (!ret) |
98abed02 RM |
1475 | return ret; |
1476 | ||
14dd0b81 RM |
1477 | if (unlikely(ret < 0)) { |
1478 | /* | |
1479 | * If we have not yet seen any eligible child, | |
1480 | * then let this error code replace -ECHILD. | |
1481 | * A permission error will give the user a clue | |
1482 | * to look for security policy problems, rather | |
1483 | * than for mysterious wait bugs. | |
1484 | */ | |
1485 | if (*notask_error) | |
1486 | *notask_error = ret; | |
1487 | } | |
1488 | ||
f470021a RM |
1489 | if (likely(!ptrace) && unlikely(p->ptrace)) { |
1490 | /* | |
1491 | * This child is hidden by ptrace. | |
1492 | * We aren't allowed to see it now, but eventually we will. | |
1493 | */ | |
1494 | *notask_error = 0; | |
1495 | return 0; | |
1496 | } | |
1497 | ||
98abed02 RM |
1498 | if (p->exit_state == EXIT_DEAD) |
1499 | return 0; | |
1500 | ||
1501 | /* | |
1502 | * We don't reap group leaders with subthreads. | |
1503 | */ | |
1504 | if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p)) | |
1505 | return wait_task_zombie(p, options, infop, stat_addr, ru); | |
1506 | ||
1507 | /* | |
1508 | * It's stopped or running now, so it might | |
1509 | * later continue, exit, or stop again. | |
1510 | */ | |
1511 | *notask_error = 0; | |
1512 | ||
90bc8d8b | 1513 | if (task_stopped_code(p, ptrace)) |
f470021a RM |
1514 | return wait_task_stopped(ptrace, p, options, |
1515 | infop, stat_addr, ru); | |
98abed02 RM |
1516 | |
1517 | return wait_task_continued(p, options, infop, stat_addr, ru); | |
1518 | } | |
1519 | ||
1520 | /* | |
1521 | * Do the work of do_wait() for one thread in the group, @tsk. | |
1522 | * | |
1523 | * -ECHILD should be in *@notask_error before the first call. | |
1524 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1525 | * Returns zero if the search for a child should continue; then | |
14dd0b81 RM |
1526 | * *@notask_error is 0 if there were any eligible children, |
1527 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 RM |
1528 | */ |
1529 | static int do_wait_thread(struct task_struct *tsk, int *notask_error, | |
1530 | enum pid_type type, struct pid *pid, int options, | |
1531 | struct siginfo __user *infop, int __user *stat_addr, | |
1532 | struct rusage __user *ru) | |
1533 | { | |
1534 | struct task_struct *p; | |
1535 | ||
1536 | list_for_each_entry(p, &tsk->children, sibling) { | |
f470021a RM |
1537 | /* |
1538 | * Do not consider detached threads. | |
1539 | */ | |
1540 | if (!task_detached(p)) { | |
1541 | int ret = wait_consider_task(tsk, 0, p, notask_error, | |
1542 | type, pid, options, | |
1543 | infop, stat_addr, ru); | |
1544 | if (ret) | |
1545 | return ret; | |
1546 | } | |
98abed02 RM |
1547 | } |
1548 | ||
1549 | return 0; | |
1550 | } | |
1551 | ||
1552 | static int ptrace_do_wait(struct task_struct *tsk, int *notask_error, | |
1553 | enum pid_type type, struct pid *pid, int options, | |
1554 | struct siginfo __user *infop, int __user *stat_addr, | |
1555 | struct rusage __user *ru) | |
1556 | { | |
1557 | struct task_struct *p; | |
1558 | ||
1559 | /* | |
f470021a | 1560 | * Traditionally we see ptrace'd stopped tasks regardless of options. |
98abed02 | 1561 | */ |
f470021a | 1562 | options |= WUNTRACED; |
98abed02 | 1563 | |
f470021a RM |
1564 | list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { |
1565 | int ret = wait_consider_task(tsk, 1, p, notask_error, | |
1566 | type, pid, options, | |
1567 | infop, stat_addr, ru); | |
1568 | if (ret) | |
98abed02 | 1569 | return ret; |
98abed02 RM |
1570 | } |
1571 | ||
1572 | return 0; | |
1573 | } | |
1574 | ||
161550d7 EB |
1575 | static long do_wait(enum pid_type type, struct pid *pid, int options, |
1576 | struct siginfo __user *infop, int __user *stat_addr, | |
1577 | struct rusage __user *ru) | |
1da177e4 LT |
1578 | { |
1579 | DECLARE_WAITQUEUE(wait, current); | |
1580 | struct task_struct *tsk; | |
98abed02 | 1581 | int retval; |
1da177e4 | 1582 | |
0a16b607 MD |
1583 | trace_sched_process_wait(pid); |
1584 | ||
1da177e4 LT |
1585 | add_wait_queue(¤t->signal->wait_chldexit,&wait); |
1586 | repeat: | |
98abed02 RM |
1587 | /* |
1588 | * If there is nothing that can match our critiera just get out. | |
1589 | * We will clear @retval to zero if we see any child that might later | |
1590 | * match our criteria, even if we are not able to reap it yet. | |
1591 | */ | |
161550d7 EB |
1592 | retval = -ECHILD; |
1593 | if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) | |
1594 | goto end; | |
1595 | ||
1da177e4 LT |
1596 | current->state = TASK_INTERRUPTIBLE; |
1597 | read_lock(&tasklist_lock); | |
1598 | tsk = current; | |
1599 | do { | |
98abed02 RM |
1600 | int tsk_result = do_wait_thread(tsk, &retval, |
1601 | type, pid, options, | |
1602 | infop, stat_addr, ru); | |
1603 | if (!tsk_result) | |
1604 | tsk_result = ptrace_do_wait(tsk, &retval, | |
1605 | type, pid, options, | |
1606 | infop, stat_addr, ru); | |
1607 | if (tsk_result) { | |
1608 | /* | |
1609 | * tasklist_lock is unlocked and we have a final result. | |
1610 | */ | |
1611 | retval = tsk_result; | |
1612 | goto end; | |
1da177e4 | 1613 | } |
98abed02 | 1614 | |
1da177e4 LT |
1615 | if (options & __WNOTHREAD) |
1616 | break; | |
1617 | tsk = next_thread(tsk); | |
125e1874 | 1618 | BUG_ON(tsk->signal != current->signal); |
1da177e4 | 1619 | } while (tsk != current); |
1da177e4 | 1620 | read_unlock(&tasklist_lock); |
f2cc3eb1 | 1621 | |
98abed02 | 1622 | if (!retval && !(options & WNOHANG)) { |
1da177e4 | 1623 | retval = -ERESTARTSYS; |
98abed02 RM |
1624 | if (!signal_pending(current)) { |
1625 | schedule(); | |
1626 | goto repeat; | |
1627 | } | |
1da177e4 | 1628 | } |
98abed02 | 1629 | |
1da177e4 LT |
1630 | end: |
1631 | current->state = TASK_RUNNING; | |
1632 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1633 | if (infop) { | |
1634 | if (retval > 0) | |
9cbab810 | 1635 | retval = 0; |
1da177e4 LT |
1636 | else { |
1637 | /* | |
1638 | * For a WNOHANG return, clear out all the fields | |
1639 | * we would set so the user can easily tell the | |
1640 | * difference. | |
1641 | */ | |
1642 | if (!retval) | |
1643 | retval = put_user(0, &infop->si_signo); | |
1644 | if (!retval) | |
1645 | retval = put_user(0, &infop->si_errno); | |
1646 | if (!retval) | |
1647 | retval = put_user(0, &infop->si_code); | |
1648 | if (!retval) | |
1649 | retval = put_user(0, &infop->si_pid); | |
1650 | if (!retval) | |
1651 | retval = put_user(0, &infop->si_uid); | |
1652 | if (!retval) | |
1653 | retval = put_user(0, &infop->si_status); | |
1654 | } | |
1655 | } | |
1656 | return retval; | |
1657 | } | |
1658 | ||
17da2bd9 HC |
1659 | SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, |
1660 | infop, int, options, struct rusage __user *, ru) | |
1da177e4 | 1661 | { |
161550d7 EB |
1662 | struct pid *pid = NULL; |
1663 | enum pid_type type; | |
1da177e4 LT |
1664 | long ret; |
1665 | ||
1666 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1667 | return -EINVAL; | |
1668 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1669 | return -EINVAL; | |
1670 | ||
1671 | switch (which) { | |
1672 | case P_ALL: | |
161550d7 | 1673 | type = PIDTYPE_MAX; |
1da177e4 LT |
1674 | break; |
1675 | case P_PID: | |
161550d7 EB |
1676 | type = PIDTYPE_PID; |
1677 | if (upid <= 0) | |
1da177e4 LT |
1678 | return -EINVAL; |
1679 | break; | |
1680 | case P_PGID: | |
161550d7 EB |
1681 | type = PIDTYPE_PGID; |
1682 | if (upid <= 0) | |
1da177e4 | 1683 | return -EINVAL; |
1da177e4 LT |
1684 | break; |
1685 | default: | |
1686 | return -EINVAL; | |
1687 | } | |
1688 | ||
161550d7 EB |
1689 | if (type < PIDTYPE_MAX) |
1690 | pid = find_get_pid(upid); | |
1691 | ret = do_wait(type, pid, options, infop, NULL, ru); | |
1692 | put_pid(pid); | |
1da177e4 LT |
1693 | |
1694 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1695 | asmlinkage_protect(5, ret, which, upid, infop, options, ru); |
1da177e4 LT |
1696 | return ret; |
1697 | } | |
1698 | ||
754fe8d2 HC |
1699 | SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, |
1700 | int, options, struct rusage __user *, ru) | |
1da177e4 | 1701 | { |
161550d7 EB |
1702 | struct pid *pid = NULL; |
1703 | enum pid_type type; | |
1da177e4 LT |
1704 | long ret; |
1705 | ||
1706 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1707 | __WNOTHREAD|__WCLONE|__WALL)) | |
1708 | return -EINVAL; | |
161550d7 EB |
1709 | |
1710 | if (upid == -1) | |
1711 | type = PIDTYPE_MAX; | |
1712 | else if (upid < 0) { | |
1713 | type = PIDTYPE_PGID; | |
1714 | pid = find_get_pid(-upid); | |
1715 | } else if (upid == 0) { | |
1716 | type = PIDTYPE_PGID; | |
2ae448ef | 1717 | pid = get_task_pid(current, PIDTYPE_PGID); |
161550d7 EB |
1718 | } else /* upid > 0 */ { |
1719 | type = PIDTYPE_PID; | |
1720 | pid = find_get_pid(upid); | |
1721 | } | |
1722 | ||
1723 | ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru); | |
1724 | put_pid(pid); | |
1da177e4 LT |
1725 | |
1726 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1727 | asmlinkage_protect(4, ret, upid, stat_addr, options, ru); |
1da177e4 LT |
1728 | return ret; |
1729 | } | |
1730 | ||
1731 | #ifdef __ARCH_WANT_SYS_WAITPID | |
1732 | ||
1733 | /* | |
1734 | * sys_waitpid() remains for compatibility. waitpid() should be | |
1735 | * implemented by calling sys_wait4() from libc.a. | |
1736 | */ | |
17da2bd9 | 1737 | SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options) |
1da177e4 LT |
1738 | { |
1739 | return sys_wait4(pid, stat_addr, options, NULL); | |
1740 | } | |
1741 | ||
1742 | #endif |