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> |
0a16b607 | 51 | #include <trace/sched.h> |
1da177e4 LT |
52 | |
53 | #include <asm/uaccess.h> | |
54 | #include <asm/unistd.h> | |
55 | #include <asm/pgtable.h> | |
56 | #include <asm/mmu_context.h> | |
d84f4f99 | 57 | #include "cred-internals.h" |
1da177e4 | 58 | |
7e066fb8 MD |
59 | DEFINE_TRACE(sched_process_free); |
60 | DEFINE_TRACE(sched_process_exit); | |
61 | DEFINE_TRACE(sched_process_wait); | |
1da177e4 | 62 | |
408b664a AB |
63 | static void exit_mm(struct task_struct * tsk); |
64 | ||
1da177e4 LT |
65 | static void __unhash_process(struct task_struct *p) |
66 | { | |
67 | nr_threads--; | |
68 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
69 | if (thread_group_leader(p)) { |
70 | detach_pid(p, PIDTYPE_PGID); | |
71 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 72 | |
5e85d4ab | 73 | list_del_rcu(&p->tasks); |
73b9ebfe | 74 | __get_cpu_var(process_counts)--; |
1da177e4 | 75 | } |
47e65328 | 76 | list_del_rcu(&p->thread_group); |
f470021a | 77 | list_del_init(&p->sibling); |
1da177e4 LT |
78 | } |
79 | ||
6a14c5c9 ON |
80 | /* |
81 | * This function expects the tasklist_lock write-locked. | |
82 | */ | |
83 | static void __exit_signal(struct task_struct *tsk) | |
84 | { | |
85 | struct signal_struct *sig = tsk->signal; | |
86 | struct sighand_struct *sighand; | |
87 | ||
88 | BUG_ON(!sig); | |
89 | BUG_ON(!atomic_read(&sig->count)); | |
90 | ||
6a14c5c9 ON |
91 | sighand = rcu_dereference(tsk->sighand); |
92 | spin_lock(&sighand->siglock); | |
93 | ||
94 | posix_cpu_timers_exit(tsk); | |
95 | if (atomic_dec_and_test(&sig->count)) | |
96 | posix_cpu_timers_exit_group(tsk); | |
97 | else { | |
98 | /* | |
99 | * If there is any task waiting for the group exit | |
100 | * then notify it: | |
101 | */ | |
6db840fa | 102 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) |
6a14c5c9 | 103 | wake_up_process(sig->group_exit_task); |
6db840fa | 104 | |
6a14c5c9 ON |
105 | if (tsk == sig->curr_target) |
106 | sig->curr_target = next_thread(tsk); | |
107 | /* | |
108 | * Accumulate here the counters for all threads but the | |
109 | * group leader as they die, so they can be added into | |
110 | * the process-wide totals when those are taken. | |
111 | * The group leader stays around as a zombie as long | |
112 | * as there are other threads. When it gets reaped, | |
113 | * the exit.c code will add its counts into these totals. | |
114 | * We won't ever get here for the group leader, since it | |
115 | * will have been the last reference on the signal_struct. | |
116 | */ | |
32bd671d PZ |
117 | sig->utime = cputime_add(sig->utime, task_utime(tsk)); |
118 | sig->stime = cputime_add(sig->stime, task_stime(tsk)); | |
49048622 | 119 | sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); |
6a14c5c9 ON |
120 | sig->min_flt += tsk->min_flt; |
121 | sig->maj_flt += tsk->maj_flt; | |
122 | sig->nvcsw += tsk->nvcsw; | |
123 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
124 | sig->inblock += task_io_get_inblock(tsk); |
125 | sig->oublock += task_io_get_oublock(tsk); | |
5995477a | 126 | task_io_accounting_add(&sig->ioac, &tsk->ioac); |
32bd671d | 127 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
6a14c5c9 ON |
128 | sig = NULL; /* Marker for below. */ |
129 | } | |
130 | ||
5876700c ON |
131 | __unhash_process(tsk); |
132 | ||
da7978b0 ON |
133 | /* |
134 | * Do this under ->siglock, we can race with another thread | |
135 | * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals. | |
136 | */ | |
137 | flush_sigqueue(&tsk->pending); | |
138 | ||
6a14c5c9 | 139 | tsk->signal = NULL; |
a7e5328a | 140 | tsk->sighand = NULL; |
6a14c5c9 | 141 | spin_unlock(&sighand->siglock); |
6a14c5c9 | 142 | |
a7e5328a | 143 | __cleanup_sighand(sighand); |
6a14c5c9 | 144 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
6a14c5c9 ON |
145 | if (sig) { |
146 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 147 | taskstats_tgid_free(sig); |
ad474cac ON |
148 | /* |
149 | * Make sure ->signal can't go away under rq->lock, | |
150 | * see account_group_exec_runtime(). | |
151 | */ | |
152 | task_rq_unlock_wait(tsk); | |
6a14c5c9 ON |
153 | __cleanup_signal(sig); |
154 | } | |
155 | } | |
156 | ||
8c7904a0 EB |
157 | static void delayed_put_task_struct(struct rcu_head *rhp) |
158 | { | |
0a16b607 MD |
159 | struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); |
160 | ||
eef6cbf5 IM |
161 | #ifdef CONFIG_PERF_COUNTERS |
162 | WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list)); | |
163 | #endif | |
0a16b607 MD |
164 | trace_sched_process_free(tsk); |
165 | put_task_struct(tsk); | |
8c7904a0 EB |
166 | } |
167 | ||
f470021a | 168 | |
1da177e4 LT |
169 | void release_task(struct task_struct * p) |
170 | { | |
36c8b586 | 171 | struct task_struct *leader; |
1da177e4 | 172 | int zap_leader; |
1f09f974 | 173 | repeat: |
dae33574 | 174 | tracehook_prepare_release_task(p); |
c69e8d9c DH |
175 | /* don't need to get the RCU readlock here - the process is dead and |
176 | * can't be modifying its own credentials */ | |
177 | atomic_dec(&__task_cred(p)->user->processes); | |
178 | ||
60347f67 | 179 | proc_flush_task(p); |
0203026b | 180 | |
1da177e4 | 181 | write_lock_irq(&tasklist_lock); |
dae33574 | 182 | tracehook_finish_release_task(p); |
1da177e4 | 183 | __exit_signal(p); |
35f5cad8 | 184 | |
1da177e4 LT |
185 | /* |
186 | * If we are the last non-leader member of the thread | |
187 | * group, and the leader is zombie, then notify the | |
188 | * group leader's parent process. (if it wants notification.) | |
189 | */ | |
190 | zap_leader = 0; | |
191 | leader = p->group_leader; | |
192 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
d839fd4d | 193 | BUG_ON(task_detached(leader)); |
1da177e4 LT |
194 | do_notify_parent(leader, leader->exit_signal); |
195 | /* | |
196 | * If we were the last child thread and the leader has | |
197 | * exited already, and the leader's parent ignores SIGCHLD, | |
198 | * then we are the one who should release the leader. | |
199 | * | |
200 | * do_notify_parent() will have marked it self-reaping in | |
201 | * that case. | |
202 | */ | |
d839fd4d | 203 | zap_leader = task_detached(leader); |
dae33574 RM |
204 | |
205 | /* | |
206 | * This maintains the invariant that release_task() | |
207 | * only runs on a task in EXIT_DEAD, just for sanity. | |
208 | */ | |
209 | if (zap_leader) | |
210 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
211 | } |
212 | ||
1da177e4 | 213 | write_unlock_irq(&tasklist_lock); |
1da177e4 | 214 | release_thread(p); |
8c7904a0 | 215 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
216 | |
217 | p = leader; | |
218 | if (unlikely(zap_leader)) | |
219 | goto repeat; | |
220 | } | |
221 | ||
1da177e4 LT |
222 | /* |
223 | * This checks not only the pgrp, but falls back on the pid if no | |
224 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
225 | * without this... | |
04a2e6a5 EB |
226 | * |
227 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 228 | */ |
04a2e6a5 | 229 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
230 | { |
231 | struct task_struct *p; | |
04a2e6a5 | 232 | struct pid *sid = NULL; |
62dfb554 | 233 | |
04a2e6a5 | 234 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 235 | if (p == NULL) |
04a2e6a5 | 236 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 237 | if (p != NULL) |
04a2e6a5 | 238 | sid = task_session(p); |
62dfb554 | 239 | |
1da177e4 LT |
240 | return sid; |
241 | } | |
242 | ||
243 | /* | |
244 | * Determine if a process group is "orphaned", according to the POSIX | |
245 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
246 | * by terminal-generated stop signals. Newly orphaned process groups are | |
247 | * to receive a SIGHUP and a SIGCONT. | |
248 | * | |
249 | * "I ask you, have you ever known what it is to be an orphan?" | |
250 | */ | |
0475ac08 | 251 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
252 | { |
253 | struct task_struct *p; | |
1da177e4 | 254 | |
0475ac08 | 255 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
05e83df6 ON |
256 | if ((p == ignored_task) || |
257 | (p->exit_state && thread_group_empty(p)) || | |
258 | is_global_init(p->real_parent)) | |
1da177e4 | 259 | continue; |
05e83df6 | 260 | |
0475ac08 | 261 | if (task_pgrp(p->real_parent) != pgrp && |
05e83df6 ON |
262 | task_session(p->real_parent) == task_session(p)) |
263 | return 0; | |
0475ac08 | 264 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
05e83df6 ON |
265 | |
266 | return 1; | |
1da177e4 LT |
267 | } |
268 | ||
3e7cd6c4 | 269 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
270 | { |
271 | int retval; | |
272 | ||
273 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 274 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
275 | read_unlock(&tasklist_lock); |
276 | ||
277 | return retval; | |
278 | } | |
279 | ||
0475ac08 | 280 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
281 | { |
282 | int retval = 0; | |
283 | struct task_struct *p; | |
284 | ||
0475ac08 | 285 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
338077e5 | 286 | if (!task_is_stopped(p)) |
1da177e4 | 287 | continue; |
1da177e4 LT |
288 | retval = 1; |
289 | break; | |
0475ac08 | 290 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
291 | return retval; |
292 | } | |
293 | ||
f49ee505 ON |
294 | /* |
295 | * Check to see if any process groups have become orphaned as | |
296 | * a result of our exiting, and if they have any stopped jobs, | |
297 | * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
298 | */ | |
299 | static void | |
300 | kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) | |
301 | { | |
302 | struct pid *pgrp = task_pgrp(tsk); | |
303 | struct task_struct *ignored_task = tsk; | |
304 | ||
305 | if (!parent) | |
306 | /* exit: our father is in a different pgrp than | |
307 | * we are and we were the only connection outside. | |
308 | */ | |
309 | parent = tsk->real_parent; | |
310 | else | |
311 | /* reparent: our child is in a different pgrp than | |
312 | * we are, and it was the only connection outside. | |
313 | */ | |
314 | ignored_task = NULL; | |
315 | ||
316 | if (task_pgrp(parent) != pgrp && | |
317 | task_session(parent) == task_session(tsk) && | |
318 | will_become_orphaned_pgrp(pgrp, ignored_task) && | |
319 | has_stopped_jobs(pgrp)) { | |
320 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
321 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
322 | } | |
323 | } | |
324 | ||
1da177e4 | 325 | /** |
49d769d5 | 326 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
327 | * |
328 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
329 | * it ever exits, it should generally reparent itself to kthreadd so it |
330 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
331 | * |
332 | * The various task state such as scheduling policy and priority may have | |
333 | * been inherited from a user process, so we reset them to sane values here. | |
334 | * | |
49d769d5 | 335 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 336 | */ |
49d769d5 | 337 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
338 | { |
339 | write_lock_irq(&tasklist_lock); | |
340 | ||
341 | ptrace_unlink(current); | |
342 | /* Reparent to init */ | |
49d769d5 | 343 | current->real_parent = current->parent = kthreadd_task; |
f470021a | 344 | list_move_tail(¤t->sibling, ¤t->real_parent->children); |
1da177e4 LT |
345 | |
346 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
347 | current->exit_signal = SIGCHLD; | |
348 | ||
e05606d3 | 349 | if (task_nice(current) < 0) |
1da177e4 LT |
350 | set_user_nice(current, 0); |
351 | /* cpus_allowed? */ | |
352 | /* rt_priority? */ | |
353 | /* signals? */ | |
1da177e4 LT |
354 | memcpy(current->signal->rlim, init_task.signal->rlim, |
355 | sizeof(current->signal->rlim)); | |
d84f4f99 DH |
356 | |
357 | atomic_inc(&init_cred.usage); | |
358 | commit_creds(&init_cred); | |
1da177e4 | 359 | write_unlock_irq(&tasklist_lock); |
1da177e4 LT |
360 | } |
361 | ||
8520d7c7 | 362 | void __set_special_pids(struct pid *pid) |
1da177e4 | 363 | { |
e19f247a | 364 | struct task_struct *curr = current->group_leader; |
1da177e4 | 365 | |
1b0f7ffd | 366 | if (task_session(curr) != pid) |
7d8da096 | 367 | change_pid(curr, PIDTYPE_SID, pid); |
1b0f7ffd ON |
368 | |
369 | if (task_pgrp(curr) != pid) | |
7d8da096 | 370 | change_pid(curr, PIDTYPE_PGID, pid); |
1da177e4 LT |
371 | } |
372 | ||
8520d7c7 | 373 | static void set_special_pids(struct pid *pid) |
1da177e4 LT |
374 | { |
375 | write_lock_irq(&tasklist_lock); | |
8520d7c7 | 376 | __set_special_pids(pid); |
1da177e4 LT |
377 | write_unlock_irq(&tasklist_lock); |
378 | } | |
379 | ||
380 | /* | |
381 | * Let kernel threads use this to say that they | |
382 | * allow a certain signal (since daemonize() will | |
383 | * have disabled all of them by default). | |
384 | */ | |
385 | int allow_signal(int sig) | |
386 | { | |
7ed20e1a | 387 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
388 | return -EINVAL; |
389 | ||
390 | spin_lock_irq(¤t->sighand->siglock); | |
391 | sigdelset(¤t->blocked, sig); | |
392 | if (!current->mm) { | |
393 | /* Kernel threads handle their own signals. | |
394 | Let the signal code know it'll be handled, so | |
395 | that they don't get converted to SIGKILL or | |
396 | just silently dropped */ | |
397 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
398 | } | |
399 | recalc_sigpending(); | |
400 | spin_unlock_irq(¤t->sighand->siglock); | |
401 | return 0; | |
402 | } | |
403 | ||
404 | EXPORT_SYMBOL(allow_signal); | |
405 | ||
406 | int disallow_signal(int sig) | |
407 | { | |
7ed20e1a | 408 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
409 | return -EINVAL; |
410 | ||
411 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 412 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
413 | recalc_sigpending(); |
414 | spin_unlock_irq(¤t->sighand->siglock); | |
415 | return 0; | |
416 | } | |
417 | ||
418 | EXPORT_SYMBOL(disallow_signal); | |
419 | ||
420 | /* | |
421 | * Put all the gunge required to become a kernel thread without | |
422 | * attached user resources in one place where it belongs. | |
423 | */ | |
424 | ||
425 | void daemonize(const char *name, ...) | |
426 | { | |
427 | va_list args; | |
1da177e4 LT |
428 | sigset_t blocked; |
429 | ||
430 | va_start(args, name); | |
431 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
432 | va_end(args); | |
433 | ||
434 | /* | |
435 | * If we were started as result of loading a module, close all of the | |
436 | * user space pages. We don't need them, and if we didn't close them | |
437 | * they would be locked into memory. | |
438 | */ | |
439 | exit_mm(current); | |
83144186 RW |
440 | /* |
441 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
442 | * or suspend transition begins right now. | |
443 | */ | |
7b34e428 | 444 | current->flags |= (PF_NOFREEZE | PF_KTHREAD); |
1da177e4 | 445 | |
8520d7c7 ON |
446 | if (current->nsproxy != &init_nsproxy) { |
447 | get_nsproxy(&init_nsproxy); | |
448 | switch_task_namespaces(current, &init_nsproxy); | |
449 | } | |
297bd42b | 450 | set_special_pids(&init_struct_pid); |
24ec839c | 451 | proc_clear_tty(current); |
1da177e4 LT |
452 | |
453 | /* Block and flush all signals */ | |
454 | sigfillset(&blocked); | |
455 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
456 | flush_signals(current); | |
457 | ||
458 | /* Become as one with the init task */ | |
459 | ||
3e93cd67 | 460 | daemonize_fs_struct(); |
d4c5e41f | 461 | exit_files(current); |
1da177e4 LT |
462 | current->files = init_task.files; |
463 | atomic_inc(¤t->files->count); | |
464 | ||
49d769d5 | 465 | reparent_to_kthreadd(); |
1da177e4 LT |
466 | } |
467 | ||
468 | EXPORT_SYMBOL(daemonize); | |
469 | ||
858119e1 | 470 | static void close_files(struct files_struct * files) |
1da177e4 LT |
471 | { |
472 | int i, j; | |
badf1662 | 473 | struct fdtable *fdt; |
1da177e4 LT |
474 | |
475 | j = 0; | |
4fb3a538 DS |
476 | |
477 | /* | |
478 | * It is safe to dereference the fd table without RCU or | |
479 | * ->file_lock because this is the last reference to the | |
480 | * files structure. | |
481 | */ | |
badf1662 | 482 | fdt = files_fdtable(files); |
1da177e4 LT |
483 | for (;;) { |
484 | unsigned long set; | |
485 | i = j * __NFDBITS; | |
bbea9f69 | 486 | if (i >= fdt->max_fds) |
1da177e4 | 487 | break; |
badf1662 | 488 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
489 | while (set) { |
490 | if (set & 1) { | |
badf1662 | 491 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 492 | if (file) { |
1da177e4 | 493 | filp_close(file, files); |
944be0b2 IM |
494 | cond_resched(); |
495 | } | |
1da177e4 LT |
496 | } |
497 | i++; | |
498 | set >>= 1; | |
499 | } | |
500 | } | |
501 | } | |
502 | ||
503 | struct files_struct *get_files_struct(struct task_struct *task) | |
504 | { | |
505 | struct files_struct *files; | |
506 | ||
507 | task_lock(task); | |
508 | files = task->files; | |
509 | if (files) | |
510 | atomic_inc(&files->count); | |
511 | task_unlock(task); | |
512 | ||
513 | return files; | |
514 | } | |
515 | ||
7ad5b3a5 | 516 | void put_files_struct(struct files_struct *files) |
1da177e4 | 517 | { |
badf1662 DS |
518 | struct fdtable *fdt; |
519 | ||
1da177e4 LT |
520 | if (atomic_dec_and_test(&files->count)) { |
521 | close_files(files); | |
522 | /* | |
523 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
524 | * If the fdtable was embedded, pass files for freeing |
525 | * at the end of the RCU grace period. Otherwise, | |
526 | * you can free files immediately. | |
1da177e4 | 527 | */ |
badf1662 | 528 | fdt = files_fdtable(files); |
4fd45812 | 529 | if (fdt != &files->fdtab) |
ab2af1f5 | 530 | kmem_cache_free(files_cachep, files); |
01b2d93c | 531 | free_fdtable(fdt); |
1da177e4 LT |
532 | } |
533 | } | |
534 | ||
3b125388 | 535 | void reset_files_struct(struct files_struct *files) |
3b9b8ab6 | 536 | { |
3b125388 | 537 | struct task_struct *tsk = current; |
3b9b8ab6 KK |
538 | struct files_struct *old; |
539 | ||
540 | old = tsk->files; | |
541 | task_lock(tsk); | |
542 | tsk->files = files; | |
543 | task_unlock(tsk); | |
544 | put_files_struct(old); | |
545 | } | |
3b9b8ab6 | 546 | |
1ec7f1dd | 547 | void exit_files(struct task_struct *tsk) |
1da177e4 LT |
548 | { |
549 | struct files_struct * files = tsk->files; | |
550 | ||
551 | if (files) { | |
552 | task_lock(tsk); | |
553 | tsk->files = NULL; | |
554 | task_unlock(tsk); | |
555 | put_files_struct(files); | |
556 | } | |
557 | } | |
558 | ||
cf475ad2 BS |
559 | #ifdef CONFIG_MM_OWNER |
560 | /* | |
561 | * Task p is exiting and it owned mm, lets find a new owner for it | |
562 | */ | |
563 | static inline int | |
564 | mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) | |
565 | { | |
566 | /* | |
567 | * If there are other users of the mm and the owner (us) is exiting | |
568 | * we need to find a new owner to take on the responsibility. | |
569 | */ | |
cf475ad2 BS |
570 | if (atomic_read(&mm->mm_users) <= 1) |
571 | return 0; | |
572 | if (mm->owner != p) | |
573 | return 0; | |
574 | return 1; | |
575 | } | |
576 | ||
577 | void mm_update_next_owner(struct mm_struct *mm) | |
578 | { | |
579 | struct task_struct *c, *g, *p = current; | |
580 | ||
581 | retry: | |
582 | if (!mm_need_new_owner(mm, p)) | |
583 | return; | |
584 | ||
585 | read_lock(&tasklist_lock); | |
586 | /* | |
587 | * Search in the children | |
588 | */ | |
589 | list_for_each_entry(c, &p->children, sibling) { | |
590 | if (c->mm == mm) | |
591 | goto assign_new_owner; | |
592 | } | |
593 | ||
594 | /* | |
595 | * Search in the siblings | |
596 | */ | |
597 | list_for_each_entry(c, &p->parent->children, sibling) { | |
598 | if (c->mm == mm) | |
599 | goto assign_new_owner; | |
600 | } | |
601 | ||
602 | /* | |
603 | * Search through everything else. We should not get | |
604 | * here often | |
605 | */ | |
606 | do_each_thread(g, c) { | |
607 | if (c->mm == mm) | |
608 | goto assign_new_owner; | |
609 | } while_each_thread(g, c); | |
610 | ||
611 | read_unlock(&tasklist_lock); | |
31a78f23 BS |
612 | /* |
613 | * We found no owner yet mm_users > 1: this implies that we are | |
614 | * most likely racing with swapoff (try_to_unuse()) or /proc or | |
e5991371 | 615 | * ptrace or page migration (get_task_mm()). Mark owner as NULL. |
31a78f23 | 616 | */ |
31a78f23 | 617 | mm->owner = NULL; |
cf475ad2 BS |
618 | return; |
619 | ||
620 | assign_new_owner: | |
621 | BUG_ON(c == p); | |
622 | get_task_struct(c); | |
623 | /* | |
624 | * The task_lock protects c->mm from changing. | |
625 | * We always want mm->owner->mm == mm | |
626 | */ | |
627 | task_lock(c); | |
e5991371 HD |
628 | /* |
629 | * Delay read_unlock() till we have the task_lock() | |
630 | * to ensure that c does not slip away underneath us | |
631 | */ | |
632 | read_unlock(&tasklist_lock); | |
cf475ad2 BS |
633 | if (c->mm != mm) { |
634 | task_unlock(c); | |
635 | put_task_struct(c); | |
636 | goto retry; | |
637 | } | |
cf475ad2 BS |
638 | mm->owner = c; |
639 | task_unlock(c); | |
640 | put_task_struct(c); | |
641 | } | |
642 | #endif /* CONFIG_MM_OWNER */ | |
643 | ||
1da177e4 LT |
644 | /* |
645 | * Turn us into a lazy TLB process if we | |
646 | * aren't already.. | |
647 | */ | |
408b664a | 648 | static void exit_mm(struct task_struct * tsk) |
1da177e4 LT |
649 | { |
650 | struct mm_struct *mm = tsk->mm; | |
b564daf8 | 651 | struct core_state *core_state; |
1da177e4 LT |
652 | |
653 | mm_release(tsk, mm); | |
654 | if (!mm) | |
655 | return; | |
656 | /* | |
657 | * Serialize with any possible pending coredump. | |
999d9fc1 | 658 | * We must hold mmap_sem around checking core_state |
1da177e4 | 659 | * and clearing tsk->mm. The core-inducing thread |
999d9fc1 | 660 | * will increment ->nr_threads for each thread in the |
1da177e4 LT |
661 | * group with ->mm != NULL. |
662 | */ | |
663 | down_read(&mm->mmap_sem); | |
b564daf8 ON |
664 | core_state = mm->core_state; |
665 | if (core_state) { | |
666 | struct core_thread self; | |
1da177e4 | 667 | up_read(&mm->mmap_sem); |
c5f1cc8c | 668 | |
b564daf8 ON |
669 | self.task = tsk; |
670 | self.next = xchg(&core_state->dumper.next, &self); | |
671 | /* | |
672 | * Implies mb(), the result of xchg() must be visible | |
673 | * to core_state->dumper. | |
674 | */ | |
675 | if (atomic_dec_and_test(&core_state->nr_threads)) | |
676 | complete(&core_state->startup); | |
1da177e4 | 677 | |
a94e2d40 ON |
678 | for (;;) { |
679 | set_task_state(tsk, TASK_UNINTERRUPTIBLE); | |
680 | if (!self.task) /* see coredump_finish() */ | |
681 | break; | |
682 | schedule(); | |
683 | } | |
684 | __set_task_state(tsk, TASK_RUNNING); | |
1da177e4 LT |
685 | down_read(&mm->mmap_sem); |
686 | } | |
687 | atomic_inc(&mm->mm_count); | |
125e1874 | 688 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
689 | /* more a memory barrier than a real lock */ |
690 | task_lock(tsk); | |
691 | tsk->mm = NULL; | |
692 | up_read(&mm->mmap_sem); | |
693 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
694 | /* We don't want this task to be frozen prematurely */ |
695 | clear_freeze_flag(tsk); | |
1da177e4 | 696 | task_unlock(tsk); |
cf475ad2 | 697 | mm_update_next_owner(mm); |
1da177e4 LT |
698 | mmput(mm); |
699 | } | |
700 | ||
1da177e4 LT |
701 | /* |
702 | * When we die, we re-parent all our children. | |
703 | * Try to give them to another thread in our thread | |
704 | * group, and if no such member exists, give it to | |
84d73786 SB |
705 | * the child reaper process (ie "init") in our pid |
706 | * space. | |
1da177e4 | 707 | */ |
950bbabb ON |
708 | static struct task_struct *find_new_reaper(struct task_struct *father) |
709 | { | |
710 | struct pid_namespace *pid_ns = task_active_pid_ns(father); | |
711 | struct task_struct *thread; | |
712 | ||
713 | thread = father; | |
714 | while_each_thread(father, thread) { | |
715 | if (thread->flags & PF_EXITING) | |
716 | continue; | |
717 | if (unlikely(pid_ns->child_reaper == father)) | |
718 | pid_ns->child_reaper = thread; | |
719 | return thread; | |
720 | } | |
721 | ||
722 | if (unlikely(pid_ns->child_reaper == father)) { | |
723 | write_unlock_irq(&tasklist_lock); | |
724 | if (unlikely(pid_ns == &init_pid_ns)) | |
725 | panic("Attempted to kill init!"); | |
726 | ||
727 | zap_pid_ns_processes(pid_ns); | |
728 | write_lock_irq(&tasklist_lock); | |
729 | /* | |
730 | * We can not clear ->child_reaper or leave it alone. | |
731 | * There may by stealth EXIT_DEAD tasks on ->children, | |
732 | * forget_original_parent() must move them somewhere. | |
733 | */ | |
734 | pid_ns->child_reaper = init_pid_ns.child_reaper; | |
735 | } | |
736 | ||
737 | return pid_ns->child_reaper; | |
738 | } | |
739 | ||
5dfc80be ON |
740 | /* |
741 | * Any that need to be release_task'd are put on the @dead list. | |
742 | */ | |
743 | static void reparent_thread(struct task_struct *father, struct task_struct *p, | |
744 | struct list_head *dead) | |
745 | { | |
746 | if (p->pdeath_signal) | |
747 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
748 | ||
749 | list_move_tail(&p->sibling, &p->real_parent->children); | |
750 | ||
751 | if (task_detached(p)) | |
752 | return; | |
753 | /* | |
754 | * If this is a threaded reparent there is no need to | |
755 | * notify anyone anything has happened. | |
756 | */ | |
757 | if (same_thread_group(p->real_parent, father)) | |
758 | return; | |
759 | ||
760 | /* We don't want people slaying init. */ | |
761 | p->exit_signal = SIGCHLD; | |
762 | ||
763 | /* If it has exited notify the new parent about this child's death. */ | |
764 | if (!p->ptrace && | |
765 | p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) { | |
766 | do_notify_parent(p, p->exit_signal); | |
767 | if (task_detached(p)) { | |
768 | p->exit_state = EXIT_DEAD; | |
769 | list_move_tail(&p->sibling, dead); | |
770 | } | |
771 | } | |
772 | ||
773 | kill_orphaned_pgrp(p, father); | |
774 | } | |
775 | ||
762a24be | 776 | static void forget_original_parent(struct task_struct *father) |
1da177e4 | 777 | { |
950bbabb | 778 | struct task_struct *p, *n, *reaper; |
5dfc80be | 779 | LIST_HEAD(dead_children); |
762a24be | 780 | |
39c626ae | 781 | exit_ptrace(father); |
762a24be ON |
782 | |
783 | write_lock_irq(&tasklist_lock); | |
950bbabb | 784 | reaper = find_new_reaper(father); |
f470021a | 785 | |
03ff1797 | 786 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
84eb646b | 787 | p->real_parent = reaper; |
f470021a RM |
788 | if (p->parent == father) { |
789 | BUG_ON(p->ptrace); | |
790 | p->parent = p->real_parent; | |
791 | } | |
5dfc80be | 792 | reparent_thread(father, p, &dead_children); |
1da177e4 | 793 | } |
762a24be | 794 | write_unlock_irq(&tasklist_lock); |
5dfc80be | 795 | |
762a24be | 796 | BUG_ON(!list_empty(&father->children)); |
762a24be | 797 | |
5dfc80be ON |
798 | list_for_each_entry_safe(p, n, &dead_children, sibling) { |
799 | list_del_init(&p->sibling); | |
39c626ae ON |
800 | release_task(p); |
801 | } | |
1da177e4 LT |
802 | } |
803 | ||
804 | /* | |
805 | * Send signals to all our closest relatives so that they know | |
806 | * to properly mourn us.. | |
807 | */ | |
821c7de7 | 808 | static void exit_notify(struct task_struct *tsk, int group_dead) |
1da177e4 | 809 | { |
2b2a1ff6 RM |
810 | int signal; |
811 | void *cookie; | |
1da177e4 | 812 | |
1da177e4 LT |
813 | /* |
814 | * This does two things: | |
815 | * | |
816 | * A. Make init inherit all the child processes | |
817 | * B. Check to see if any process groups have become orphaned | |
818 | * as a result of our exiting, and if they have any stopped | |
819 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
820 | */ | |
762a24be | 821 | forget_original_parent(tsk); |
2e4a7072 | 822 | exit_task_namespaces(tsk); |
1da177e4 | 823 | |
762a24be | 824 | write_lock_irq(&tasklist_lock); |
821c7de7 ON |
825 | if (group_dead) |
826 | kill_orphaned_pgrp(tsk->group_leader, NULL); | |
1da177e4 | 827 | |
24728448 | 828 | /* Let father know we died |
1da177e4 LT |
829 | * |
830 | * Thread signals are configurable, but you aren't going to use | |
d4c5e41f | 831 | * that to send signals to arbitary processes. |
1da177e4 LT |
832 | * That stops right now. |
833 | * | |
834 | * If the parent exec id doesn't match the exec id we saved | |
835 | * when we started then we know the parent has changed security | |
836 | * domain. | |
837 | * | |
838 | * If our self_exec id doesn't match our parent_exec_id then | |
839 | * we have changed execution domain as these two values started | |
840 | * the same after a fork. | |
1da177e4 | 841 | */ |
d839fd4d | 842 | if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) && |
f49ee505 | 843 | (tsk->parent_exec_id != tsk->real_parent->self_exec_id || |
432870da | 844 | tsk->self_exec_id != tsk->parent_exec_id)) |
1da177e4 LT |
845 | tsk->exit_signal = SIGCHLD; |
846 | ||
2b2a1ff6 | 847 | signal = tracehook_notify_death(tsk, &cookie, group_dead); |
5c7edcd7 | 848 | if (signal >= 0) |
2b2a1ff6 | 849 | signal = do_notify_parent(tsk, signal); |
1da177e4 | 850 | |
5c7edcd7 | 851 | tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE; |
1da177e4 | 852 | |
2800d8d1 | 853 | /* mt-exec, de_thread() is waiting for us */ |
6db840fa | 854 | if (thread_group_leader(tsk) && |
2633f0e5 SV |
855 | tsk->signal->group_exit_task && |
856 | tsk->signal->notify_count < 0) | |
6db840fa ON |
857 | wake_up_process(tsk->signal->group_exit_task); |
858 | ||
1da177e4 LT |
859 | write_unlock_irq(&tasklist_lock); |
860 | ||
2b2a1ff6 RM |
861 | tracehook_report_death(tsk, signal, cookie, group_dead); |
862 | ||
1da177e4 | 863 | /* If the process is dead, release it - nobody will wait for it */ |
5c7edcd7 | 864 | if (signal == DEATH_REAP) |
1da177e4 | 865 | release_task(tsk); |
1da177e4 LT |
866 | } |
867 | ||
e18eecb8 JD |
868 | #ifdef CONFIG_DEBUG_STACK_USAGE |
869 | static void check_stack_usage(void) | |
870 | { | |
871 | static DEFINE_SPINLOCK(low_water_lock); | |
872 | static int lowest_to_date = THREAD_SIZE; | |
e18eecb8 JD |
873 | unsigned long free; |
874 | ||
7c9f8861 | 875 | free = stack_not_used(current); |
e18eecb8 JD |
876 | |
877 | if (free >= lowest_to_date) | |
878 | return; | |
879 | ||
880 | spin_lock(&low_water_lock); | |
881 | if (free < lowest_to_date) { | |
882 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
883 | "left\n", | |
884 | current->comm, free); | |
885 | lowest_to_date = free; | |
886 | } | |
887 | spin_unlock(&low_water_lock); | |
888 | } | |
889 | #else | |
890 | static inline void check_stack_usage(void) {} | |
891 | #endif | |
892 | ||
7ad5b3a5 | 893 | NORET_TYPE void do_exit(long code) |
1da177e4 LT |
894 | { |
895 | struct task_struct *tsk = current; | |
896 | int group_dead; | |
897 | ||
898 | profile_task_exit(tsk); | |
899 | ||
22e2c507 JA |
900 | WARN_ON(atomic_read(&tsk->fs_excl)); |
901 | ||
1da177e4 LT |
902 | if (unlikely(in_interrupt())) |
903 | panic("Aiee, killing interrupt handler!"); | |
904 | if (unlikely(!tsk->pid)) | |
905 | panic("Attempted to kill the idle task!"); | |
1da177e4 | 906 | |
30199f5a | 907 | tracehook_report_exit(&code); |
1da177e4 | 908 | |
df164db5 AN |
909 | /* |
910 | * We're taking recursive faults here in do_exit. Safest is to just | |
911 | * leave this task alone and wait for reboot. | |
912 | */ | |
913 | if (unlikely(tsk->flags & PF_EXITING)) { | |
914 | printk(KERN_ALERT | |
915 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
916 | /* |
917 | * We can do this unlocked here. The futex code uses | |
918 | * this flag just to verify whether the pi state | |
919 | * cleanup has been done or not. In the worst case it | |
920 | * loops once more. We pretend that the cleanup was | |
921 | * done as there is no way to return. Either the | |
922 | * OWNER_DIED bit is set by now or we push the blocked | |
923 | * task into the wait for ever nirwana as well. | |
924 | */ | |
925 | tsk->flags |= PF_EXITPIDONE; | |
df164db5 AN |
926 | set_current_state(TASK_UNINTERRUPTIBLE); |
927 | schedule(); | |
928 | } | |
929 | ||
3aa551c9 TG |
930 | exit_irq_thread(); |
931 | ||
d12619b5 | 932 | exit_signals(tsk); /* sets PF_EXITING */ |
778e9a9c AK |
933 | /* |
934 | * tsk->flags are checked in the futex code to protect against | |
935 | * an exiting task cleaning up the robust pi futexes. | |
936 | */ | |
d2ee7198 ON |
937 | smp_mb(); |
938 | spin_unlock_wait(&tsk->pi_lock); | |
1da177e4 | 939 | |
1da177e4 LT |
940 | if (unlikely(in_atomic())) |
941 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
ba25f9dc | 942 | current->comm, task_pid_nr(current), |
1da177e4 LT |
943 | preempt_count()); |
944 | ||
945 | acct_update_integrals(tsk); | |
901608d9 | 946 | |
1da177e4 | 947 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 948 | if (group_dead) { |
778e9a9c | 949 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 950 | exit_itimers(tsk->signal); |
c3068951 | 951 | } |
f6ec29a4 | 952 | acct_collect(code, group_dead); |
522ed776 MT |
953 | if (group_dead) |
954 | tty_audit_exit(); | |
fa84cb93 AV |
955 | if (unlikely(tsk->audit_context)) |
956 | audit_free(tsk); | |
115085ea | 957 | |
f2ab6d88 | 958 | tsk->exit_code = code; |
115085ea | 959 | taskstats_exit(tsk, group_dead); |
c757249a | 960 | |
1da177e4 LT |
961 | exit_mm(tsk); |
962 | ||
0e464814 | 963 | if (group_dead) |
f6ec29a4 | 964 | acct_process(); |
0a16b607 MD |
965 | trace_sched_process_exit(tsk); |
966 | ||
1da177e4 | 967 | exit_sem(tsk); |
1ec7f1dd AV |
968 | exit_files(tsk); |
969 | exit_fs(tsk); | |
e18eecb8 | 970 | check_stack_usage(); |
1da177e4 | 971 | exit_thread(); |
b4f48b63 | 972 | cgroup_exit(tsk, 1); |
1da177e4 LT |
973 | |
974 | if (group_dead && tsk->signal->leader) | |
975 | disassociate_ctty(1); | |
976 | ||
a1261f54 | 977 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
978 | if (tsk->binfmt) |
979 | module_put(tsk->binfmt->module); | |
980 | ||
9f46080c | 981 | proc_exit_connector(tsk); |
33b2fb30 IM |
982 | |
983 | /* | |
984 | * Flush inherited counters to the parent - before the parent | |
985 | * gets woken up by child-exit notifications. | |
986 | */ | |
987 | perf_counter_exit_task(tsk); | |
988 | ||
821c7de7 | 989 | exit_notify(tsk, group_dead); |
1da177e4 | 990 | #ifdef CONFIG_NUMA |
f0be3d32 | 991 | mpol_put(tsk->mempolicy); |
1da177e4 LT |
992 | tsk->mempolicy = NULL; |
993 | #endif | |
9b51f66d | 994 | #ifdef CONFIG_FUTEX |
c87e2837 IM |
995 | if (unlikely(!list_empty(&tsk->pi_state_list))) |
996 | exit_pi_state_list(tsk); | |
997 | if (unlikely(current->pi_state_cache)) | |
998 | kfree(current->pi_state_cache); | |
42b2dd0a | 999 | #endif |
de5097c2 | 1000 | /* |
9a11b49a | 1001 | * Make sure we are holding no locks: |
de5097c2 | 1002 | */ |
9a11b49a | 1003 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1004 | /* |
1005 | * We can do this unlocked here. The futex code uses this flag | |
1006 | * just to verify whether the pi state cleanup has been done | |
1007 | * or not. In the worst case it loops once more. | |
1008 | */ | |
1009 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1010 | |
afc847b7 AV |
1011 | if (tsk->io_context) |
1012 | exit_io_context(); | |
1013 | ||
b92ce558 JA |
1014 | if (tsk->splice_pipe) |
1015 | __free_pipe_info(tsk->splice_pipe); | |
1016 | ||
7407251a | 1017 | preempt_disable(); |
55a101f8 | 1018 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1019 | tsk->state = TASK_DEAD; |
1da177e4 LT |
1020 | schedule(); |
1021 | BUG(); | |
1022 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1023 | for (;;) |
1024 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1025 | } |
1026 | ||
012914da RA |
1027 | EXPORT_SYMBOL_GPL(do_exit); |
1028 | ||
1da177e4 LT |
1029 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1030 | { | |
1031 | if (comp) | |
1032 | complete(comp); | |
55a101f8 | 1033 | |
1da177e4 LT |
1034 | do_exit(code); |
1035 | } | |
1036 | ||
1037 | EXPORT_SYMBOL(complete_and_exit); | |
1038 | ||
754fe8d2 | 1039 | SYSCALL_DEFINE1(exit, int, error_code) |
1da177e4 LT |
1040 | { |
1041 | do_exit((error_code&0xff)<<8); | |
1042 | } | |
1043 | ||
1da177e4 LT |
1044 | /* |
1045 | * Take down every thread in the group. This is called by fatal signals | |
1046 | * as well as by sys_exit_group (below). | |
1047 | */ | |
1048 | NORET_TYPE void | |
1049 | do_group_exit(int exit_code) | |
1050 | { | |
bfc4b089 ON |
1051 | struct signal_struct *sig = current->signal; |
1052 | ||
1da177e4 LT |
1053 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
1054 | ||
bfc4b089 ON |
1055 | if (signal_group_exit(sig)) |
1056 | exit_code = sig->group_exit_code; | |
1da177e4 | 1057 | else if (!thread_group_empty(current)) { |
1da177e4 | 1058 | struct sighand_struct *const sighand = current->sighand; |
1da177e4 | 1059 | spin_lock_irq(&sighand->siglock); |
ed5d2cac | 1060 | if (signal_group_exit(sig)) |
1da177e4 LT |
1061 | /* Another thread got here before we took the lock. */ |
1062 | exit_code = sig->group_exit_code; | |
1063 | else { | |
1da177e4 | 1064 | sig->group_exit_code = exit_code; |
ed5d2cac | 1065 | sig->flags = SIGNAL_GROUP_EXIT; |
1da177e4 LT |
1066 | zap_other_threads(current); |
1067 | } | |
1068 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1069 | } |
1070 | ||
1071 | do_exit(exit_code); | |
1072 | /* NOTREACHED */ | |
1073 | } | |
1074 | ||
1075 | /* | |
1076 | * this kills every thread in the thread group. Note that any externally | |
1077 | * wait4()-ing process will get the correct exit code - even if this | |
1078 | * thread is not the thread group leader. | |
1079 | */ | |
754fe8d2 | 1080 | SYSCALL_DEFINE1(exit_group, int, error_code) |
1da177e4 LT |
1081 | { |
1082 | do_group_exit((error_code & 0xff) << 8); | |
2ed7c03e HC |
1083 | /* NOTREACHED */ |
1084 | return 0; | |
1da177e4 LT |
1085 | } |
1086 | ||
161550d7 EB |
1087 | static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) |
1088 | { | |
1089 | struct pid *pid = NULL; | |
1090 | if (type == PIDTYPE_PID) | |
1091 | pid = task->pids[type].pid; | |
1092 | else if (type < PIDTYPE_MAX) | |
1093 | pid = task->group_leader->pids[type].pid; | |
1094 | return pid; | |
1095 | } | |
1096 | ||
1097 | static int eligible_child(enum pid_type type, struct pid *pid, int options, | |
1098 | struct task_struct *p) | |
1da177e4 | 1099 | { |
73243284 RM |
1100 | int err; |
1101 | ||
161550d7 EB |
1102 | if (type < PIDTYPE_MAX) { |
1103 | if (task_pid_type(p, type) != pid) | |
1da177e4 LT |
1104 | return 0; |
1105 | } | |
1106 | ||
1da177e4 LT |
1107 | /* Wait for all children (clone and not) if __WALL is set; |
1108 | * otherwise, wait for clone children *only* if __WCLONE is | |
1109 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1110 | * A "clone" child here is one that reports to its parent | |
1111 | * using a signal other than SIGCHLD.) */ | |
1112 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1113 | && !(options & __WALL)) | |
1114 | return 0; | |
1da177e4 | 1115 | |
73243284 | 1116 | err = security_task_wait(p); |
14dd0b81 RM |
1117 | if (err) |
1118 | return err; | |
1da177e4 | 1119 | |
14dd0b81 | 1120 | return 1; |
1da177e4 LT |
1121 | } |
1122 | ||
36c8b586 | 1123 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1124 | int why, int status, |
1125 | struct siginfo __user *infop, | |
1126 | struct rusage __user *rusagep) | |
1127 | { | |
1128 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1129 | |
1da177e4 LT |
1130 | put_task_struct(p); |
1131 | if (!retval) | |
1132 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1133 | if (!retval) | |
1134 | retval = put_user(0, &infop->si_errno); | |
1135 | if (!retval) | |
1136 | retval = put_user((short)why, &infop->si_code); | |
1137 | if (!retval) | |
1138 | retval = put_user(pid, &infop->si_pid); | |
1139 | if (!retval) | |
1140 | retval = put_user(uid, &infop->si_uid); | |
1141 | if (!retval) | |
1142 | retval = put_user(status, &infop->si_status); | |
1143 | if (!retval) | |
1144 | retval = pid; | |
1145 | return retval; | |
1146 | } | |
1147 | ||
1148 | /* | |
1149 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1150 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1151 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1152 | * released the lock and the system call should return. | |
1153 | */ | |
98abed02 | 1154 | static int wait_task_zombie(struct task_struct *p, int options, |
1da177e4 LT |
1155 | struct siginfo __user *infop, |
1156 | int __user *stat_addr, struct rusage __user *ru) | |
1157 | { | |
1158 | unsigned long state; | |
2f4e6e2a | 1159 | int retval, status, traced; |
6c5f3e7b | 1160 | pid_t pid = task_pid_vnr(p); |
c69e8d9c | 1161 | uid_t uid = __task_cred(p)->uid; |
1da177e4 | 1162 | |
98abed02 RM |
1163 | if (!likely(options & WEXITED)) |
1164 | return 0; | |
1165 | ||
1166 | if (unlikely(options & WNOWAIT)) { | |
1da177e4 LT |
1167 | int exit_code = p->exit_code; |
1168 | int why, status; | |
1169 | ||
1da177e4 LT |
1170 | get_task_struct(p); |
1171 | read_unlock(&tasklist_lock); | |
1172 | if ((exit_code & 0x7f) == 0) { | |
1173 | why = CLD_EXITED; | |
1174 | status = exit_code >> 8; | |
1175 | } else { | |
1176 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1177 | status = exit_code & 0x7f; | |
1178 | } | |
1179 | return wait_noreap_copyout(p, pid, uid, why, | |
1180 | status, infop, ru); | |
1181 | } | |
1182 | ||
1183 | /* | |
1184 | * Try to move the task's state to DEAD | |
1185 | * only one thread is allowed to do this: | |
1186 | */ | |
1187 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1188 | if (state != EXIT_ZOMBIE) { | |
1189 | BUG_ON(state != EXIT_DEAD); | |
1190 | return 0; | |
1191 | } | |
1da177e4 | 1192 | |
53b6f9fb | 1193 | traced = ptrace_reparented(p); |
2f4e6e2a ON |
1194 | |
1195 | if (likely(!traced)) { | |
3795e161 JJ |
1196 | struct signal_struct *psig; |
1197 | struct signal_struct *sig; | |
f06febc9 | 1198 | struct task_cputime cputime; |
3795e161 | 1199 | |
1da177e4 LT |
1200 | /* |
1201 | * The resource counters for the group leader are in its | |
1202 | * own task_struct. Those for dead threads in the group | |
1203 | * are in its signal_struct, as are those for the child | |
1204 | * processes it has previously reaped. All these | |
1205 | * accumulate in the parent's signal_struct c* fields. | |
1206 | * | |
1207 | * We don't bother to take a lock here to protect these | |
1208 | * p->signal fields, because they are only touched by | |
1209 | * __exit_signal, which runs with tasklist_lock | |
1210 | * write-locked anyway, and so is excluded here. We do | |
1211 | * need to protect the access to p->parent->signal fields, | |
1212 | * as other threads in the parent group can be right | |
1213 | * here reaping other children at the same time. | |
f06febc9 FM |
1214 | * |
1215 | * We use thread_group_cputime() to get times for the thread | |
1216 | * group, which consolidates times for all threads in the | |
1217 | * group including the group leader. | |
1da177e4 | 1218 | */ |
2b5fe6de | 1219 | thread_group_cputime(p, &cputime); |
1da177e4 | 1220 | spin_lock_irq(&p->parent->sighand->siglock); |
3795e161 JJ |
1221 | psig = p->parent->signal; |
1222 | sig = p->signal; | |
1223 | psig->cutime = | |
1224 | cputime_add(psig->cutime, | |
f06febc9 FM |
1225 | cputime_add(cputime.utime, |
1226 | sig->cutime)); | |
3795e161 JJ |
1227 | psig->cstime = |
1228 | cputime_add(psig->cstime, | |
f06febc9 FM |
1229 | cputime_add(cputime.stime, |
1230 | sig->cstime)); | |
9ac52315 LV |
1231 | psig->cgtime = |
1232 | cputime_add(psig->cgtime, | |
1233 | cputime_add(p->gtime, | |
1234 | cputime_add(sig->gtime, | |
1235 | sig->cgtime))); | |
3795e161 JJ |
1236 | psig->cmin_flt += |
1237 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1238 | psig->cmaj_flt += | |
1239 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1240 | psig->cnvcsw += | |
1241 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1242 | psig->cnivcsw += | |
1243 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1244 | psig->cinblock += |
1245 | task_io_get_inblock(p) + | |
1246 | sig->inblock + sig->cinblock; | |
1247 | psig->coublock += | |
1248 | task_io_get_oublock(p) + | |
1249 | sig->oublock + sig->coublock; | |
5995477a AR |
1250 | task_io_accounting_add(&psig->ioac, &p->ioac); |
1251 | task_io_accounting_add(&psig->ioac, &sig->ioac); | |
1da177e4 LT |
1252 | spin_unlock_irq(&p->parent->sighand->siglock); |
1253 | } | |
1254 | ||
1255 | /* | |
1256 | * Now we are sure this task is interesting, and no other | |
1257 | * thread can reap it because we set its state to EXIT_DEAD. | |
1258 | */ | |
1259 | read_unlock(&tasklist_lock); | |
1260 | ||
1261 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1262 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1263 | ? p->signal->group_exit_code : p->exit_code; | |
1264 | if (!retval && stat_addr) | |
1265 | retval = put_user(status, stat_addr); | |
1266 | if (!retval && infop) | |
1267 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1268 | if (!retval && infop) | |
1269 | retval = put_user(0, &infop->si_errno); | |
1270 | if (!retval && infop) { | |
1271 | int why; | |
1272 | ||
1273 | if ((status & 0x7f) == 0) { | |
1274 | why = CLD_EXITED; | |
1275 | status >>= 8; | |
1276 | } else { | |
1277 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1278 | status &= 0x7f; | |
1279 | } | |
1280 | retval = put_user((short)why, &infop->si_code); | |
1281 | if (!retval) | |
1282 | retval = put_user(status, &infop->si_status); | |
1283 | } | |
1284 | if (!retval && infop) | |
3a515e4a | 1285 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1286 | if (!retval && infop) |
c69e8d9c | 1287 | retval = put_user(uid, &infop->si_uid); |
2f4e6e2a | 1288 | if (!retval) |
3a515e4a | 1289 | retval = pid; |
2f4e6e2a ON |
1290 | |
1291 | if (traced) { | |
1da177e4 | 1292 | write_lock_irq(&tasklist_lock); |
2f4e6e2a ON |
1293 | /* We dropped tasklist, ptracer could die and untrace */ |
1294 | ptrace_unlink(p); | |
1295 | /* | |
1296 | * If this is not a detached task, notify the parent. | |
1297 | * If it's still not detached after that, don't release | |
1298 | * it now. | |
1299 | */ | |
d839fd4d | 1300 | if (!task_detached(p)) { |
2f4e6e2a | 1301 | do_notify_parent(p, p->exit_signal); |
d839fd4d | 1302 | if (!task_detached(p)) { |
2f4e6e2a ON |
1303 | p->exit_state = EXIT_ZOMBIE; |
1304 | p = NULL; | |
1da177e4 LT |
1305 | } |
1306 | } | |
1307 | write_unlock_irq(&tasklist_lock); | |
1308 | } | |
1309 | if (p != NULL) | |
1310 | release_task(p); | |
2f4e6e2a | 1311 | |
1da177e4 LT |
1312 | return retval; |
1313 | } | |
1314 | ||
90bc8d8b ON |
1315 | static int *task_stopped_code(struct task_struct *p, bool ptrace) |
1316 | { | |
1317 | if (ptrace) { | |
1318 | if (task_is_stopped_or_traced(p)) | |
1319 | return &p->exit_code; | |
1320 | } else { | |
1321 | if (p->signal->flags & SIGNAL_STOP_STOPPED) | |
1322 | return &p->signal->group_exit_code; | |
1323 | } | |
1324 | return NULL; | |
1325 | } | |
1326 | ||
1da177e4 LT |
1327 | /* |
1328 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1329 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1330 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1331 | * released the lock and the system call should return. | |
1332 | */ | |
f470021a | 1333 | static int wait_task_stopped(int ptrace, struct task_struct *p, |
98abed02 | 1334 | int options, struct siginfo __user *infop, |
1da177e4 LT |
1335 | int __user *stat_addr, struct rusage __user *ru) |
1336 | { | |
90bc8d8b | 1337 | int retval, exit_code, *p_code, why; |
ee7c82da | 1338 | uid_t uid = 0; /* unneeded, required by compiler */ |
c8950783 | 1339 | pid_t pid; |
1da177e4 | 1340 | |
f470021a | 1341 | if (!(options & WUNTRACED)) |
98abed02 RM |
1342 | return 0; |
1343 | ||
ee7c82da ON |
1344 | exit_code = 0; |
1345 | spin_lock_irq(&p->sighand->siglock); | |
1346 | ||
90bc8d8b ON |
1347 | p_code = task_stopped_code(p, ptrace); |
1348 | if (unlikely(!p_code)) | |
ee7c82da ON |
1349 | goto unlock_sig; |
1350 | ||
90bc8d8b | 1351 | exit_code = *p_code; |
ee7c82da ON |
1352 | if (!exit_code) |
1353 | goto unlock_sig; | |
1354 | ||
98abed02 | 1355 | if (!unlikely(options & WNOWAIT)) |
90bc8d8b | 1356 | *p_code = 0; |
ee7c82da | 1357 | |
c69e8d9c DH |
1358 | /* don't need the RCU readlock here as we're holding a spinlock */ |
1359 | uid = __task_cred(p)->uid; | |
ee7c82da ON |
1360 | unlock_sig: |
1361 | spin_unlock_irq(&p->sighand->siglock); | |
1362 | if (!exit_code) | |
1da177e4 LT |
1363 | return 0; |
1364 | ||
1365 | /* | |
1366 | * Now we are pretty sure this task is interesting. | |
1367 | * Make sure it doesn't get reaped out from under us while we | |
1368 | * give up the lock and then examine it below. We don't want to | |
1369 | * keep holding onto the tasklist_lock while we call getrusage and | |
1370 | * possibly take page faults for user memory. | |
1371 | */ | |
1372 | get_task_struct(p); | |
6c5f3e7b | 1373 | pid = task_pid_vnr(p); |
f470021a | 1374 | why = ptrace ? CLD_TRAPPED : CLD_STOPPED; |
1da177e4 LT |
1375 | read_unlock(&tasklist_lock); |
1376 | ||
98abed02 | 1377 | if (unlikely(options & WNOWAIT)) |
1da177e4 | 1378 | return wait_noreap_copyout(p, pid, uid, |
e6ceb32a | 1379 | why, exit_code, |
1da177e4 | 1380 | infop, ru); |
1da177e4 LT |
1381 | |
1382 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1383 | if (!retval && stat_addr) | |
1384 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1385 | if (!retval && infop) | |
1386 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1387 | if (!retval && infop) | |
1388 | retval = put_user(0, &infop->si_errno); | |
1389 | if (!retval && infop) | |
6efcae46 | 1390 | retval = put_user((short)why, &infop->si_code); |
1da177e4 LT |
1391 | if (!retval && infop) |
1392 | retval = put_user(exit_code, &infop->si_status); | |
1393 | if (!retval && infop) | |
c8950783 | 1394 | retval = put_user(pid, &infop->si_pid); |
1da177e4 | 1395 | if (!retval && infop) |
ee7c82da | 1396 | retval = put_user(uid, &infop->si_uid); |
1da177e4 | 1397 | if (!retval) |
c8950783 | 1398 | retval = pid; |
1da177e4 LT |
1399 | put_task_struct(p); |
1400 | ||
1401 | BUG_ON(!retval); | |
1402 | return retval; | |
1403 | } | |
1404 | ||
1405 | /* | |
1406 | * Handle do_wait work for one task in a live, non-stopped state. | |
1407 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1408 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1409 | * released the lock and the system call should return. | |
1410 | */ | |
98abed02 | 1411 | static int wait_task_continued(struct task_struct *p, int options, |
1da177e4 LT |
1412 | struct siginfo __user *infop, |
1413 | int __user *stat_addr, struct rusage __user *ru) | |
1414 | { | |
1415 | int retval; | |
1416 | pid_t pid; | |
1417 | uid_t uid; | |
1418 | ||
98abed02 RM |
1419 | if (!unlikely(options & WCONTINUED)) |
1420 | return 0; | |
1421 | ||
1da177e4 LT |
1422 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
1423 | return 0; | |
1424 | ||
1425 | spin_lock_irq(&p->sighand->siglock); | |
1426 | /* Re-check with the lock held. */ | |
1427 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1428 | spin_unlock_irq(&p->sighand->siglock); | |
1429 | return 0; | |
1430 | } | |
98abed02 | 1431 | if (!unlikely(options & WNOWAIT)) |
1da177e4 | 1432 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; |
c69e8d9c | 1433 | uid = __task_cred(p)->uid; |
1da177e4 LT |
1434 | spin_unlock_irq(&p->sighand->siglock); |
1435 | ||
6c5f3e7b | 1436 | pid = task_pid_vnr(p); |
1da177e4 LT |
1437 | get_task_struct(p); |
1438 | read_unlock(&tasklist_lock); | |
1439 | ||
1440 | if (!infop) { | |
1441 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1442 | put_task_struct(p); | |
1443 | if (!retval && stat_addr) | |
1444 | retval = put_user(0xffff, stat_addr); | |
1445 | if (!retval) | |
3a515e4a | 1446 | retval = pid; |
1da177e4 LT |
1447 | } else { |
1448 | retval = wait_noreap_copyout(p, pid, uid, | |
1449 | CLD_CONTINUED, SIGCONT, | |
1450 | infop, ru); | |
1451 | BUG_ON(retval == 0); | |
1452 | } | |
1453 | ||
1454 | return retval; | |
1455 | } | |
1456 | ||
98abed02 RM |
1457 | /* |
1458 | * Consider @p for a wait by @parent. | |
1459 | * | |
1460 | * -ECHILD should be in *@notask_error before the first call. | |
1461 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1462 | * Returns zero if the search for a child should continue; | |
14dd0b81 RM |
1463 | * then *@notask_error is 0 if @p is an eligible child, |
1464 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 | 1465 | */ |
f470021a | 1466 | static int wait_consider_task(struct task_struct *parent, int ptrace, |
98abed02 RM |
1467 | struct task_struct *p, int *notask_error, |
1468 | enum pid_type type, struct pid *pid, int options, | |
1469 | struct siginfo __user *infop, | |
1470 | int __user *stat_addr, struct rusage __user *ru) | |
1471 | { | |
1472 | int ret = eligible_child(type, pid, options, p); | |
14dd0b81 | 1473 | if (!ret) |
98abed02 RM |
1474 | return ret; |
1475 | ||
14dd0b81 RM |
1476 | if (unlikely(ret < 0)) { |
1477 | /* | |
1478 | * If we have not yet seen any eligible child, | |
1479 | * then let this error code replace -ECHILD. | |
1480 | * A permission error will give the user a clue | |
1481 | * to look for security policy problems, rather | |
1482 | * than for mysterious wait bugs. | |
1483 | */ | |
1484 | if (*notask_error) | |
1485 | *notask_error = ret; | |
1486 | } | |
1487 | ||
f470021a RM |
1488 | if (likely(!ptrace) && unlikely(p->ptrace)) { |
1489 | /* | |
1490 | * This child is hidden by ptrace. | |
1491 | * We aren't allowed to see it now, but eventually we will. | |
1492 | */ | |
1493 | *notask_error = 0; | |
1494 | return 0; | |
1495 | } | |
1496 | ||
98abed02 RM |
1497 | if (p->exit_state == EXIT_DEAD) |
1498 | return 0; | |
1499 | ||
1500 | /* | |
1501 | * We don't reap group leaders with subthreads. | |
1502 | */ | |
1503 | if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p)) | |
1504 | return wait_task_zombie(p, options, infop, stat_addr, ru); | |
1505 | ||
1506 | /* | |
1507 | * It's stopped or running now, so it might | |
1508 | * later continue, exit, or stop again. | |
1509 | */ | |
1510 | *notask_error = 0; | |
1511 | ||
90bc8d8b | 1512 | if (task_stopped_code(p, ptrace)) |
f470021a RM |
1513 | return wait_task_stopped(ptrace, p, options, |
1514 | infop, stat_addr, ru); | |
98abed02 RM |
1515 | |
1516 | return wait_task_continued(p, options, infop, stat_addr, ru); | |
1517 | } | |
1518 | ||
1519 | /* | |
1520 | * Do the work of do_wait() for one thread in the group, @tsk. | |
1521 | * | |
1522 | * -ECHILD should be in *@notask_error before the first call. | |
1523 | * Returns nonzero for a final return, when we have unlocked tasklist_lock. | |
1524 | * Returns zero if the search for a child should continue; then | |
14dd0b81 RM |
1525 | * *@notask_error is 0 if there were any eligible children, |
1526 | * or another error from security_task_wait(), or still -ECHILD. | |
98abed02 RM |
1527 | */ |
1528 | static int do_wait_thread(struct task_struct *tsk, int *notask_error, | |
1529 | enum pid_type type, struct pid *pid, int options, | |
1530 | struct siginfo __user *infop, int __user *stat_addr, | |
1531 | struct rusage __user *ru) | |
1532 | { | |
1533 | struct task_struct *p; | |
1534 | ||
1535 | list_for_each_entry(p, &tsk->children, sibling) { | |
f470021a RM |
1536 | /* |
1537 | * Do not consider detached threads. | |
1538 | */ | |
1539 | if (!task_detached(p)) { | |
1540 | int ret = wait_consider_task(tsk, 0, p, notask_error, | |
1541 | type, pid, options, | |
1542 | infop, stat_addr, ru); | |
1543 | if (ret) | |
1544 | return ret; | |
1545 | } | |
98abed02 RM |
1546 | } |
1547 | ||
1548 | return 0; | |
1549 | } | |
1550 | ||
1551 | static int ptrace_do_wait(struct task_struct *tsk, int *notask_error, | |
1552 | enum pid_type type, struct pid *pid, int options, | |
1553 | struct siginfo __user *infop, int __user *stat_addr, | |
1554 | struct rusage __user *ru) | |
1555 | { | |
1556 | struct task_struct *p; | |
1557 | ||
1558 | /* | |
f470021a | 1559 | * Traditionally we see ptrace'd stopped tasks regardless of options. |
98abed02 | 1560 | */ |
f470021a | 1561 | options |= WUNTRACED; |
98abed02 | 1562 | |
f470021a RM |
1563 | list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { |
1564 | int ret = wait_consider_task(tsk, 1, p, notask_error, | |
1565 | type, pid, options, | |
1566 | infop, stat_addr, ru); | |
1567 | if (ret) | |
98abed02 | 1568 | return ret; |
98abed02 RM |
1569 | } |
1570 | ||
1571 | return 0; | |
1572 | } | |
1573 | ||
161550d7 EB |
1574 | static long do_wait(enum pid_type type, struct pid *pid, int options, |
1575 | struct siginfo __user *infop, int __user *stat_addr, | |
1576 | struct rusage __user *ru) | |
1da177e4 LT |
1577 | { |
1578 | DECLARE_WAITQUEUE(wait, current); | |
1579 | struct task_struct *tsk; | |
98abed02 | 1580 | int retval; |
1da177e4 | 1581 | |
0a16b607 MD |
1582 | trace_sched_process_wait(pid); |
1583 | ||
1da177e4 LT |
1584 | add_wait_queue(¤t->signal->wait_chldexit,&wait); |
1585 | repeat: | |
98abed02 RM |
1586 | /* |
1587 | * If there is nothing that can match our critiera just get out. | |
1588 | * We will clear @retval to zero if we see any child that might later | |
1589 | * match our criteria, even if we are not able to reap it yet. | |
1590 | */ | |
161550d7 EB |
1591 | retval = -ECHILD; |
1592 | if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) | |
1593 | goto end; | |
1594 | ||
1da177e4 LT |
1595 | current->state = TASK_INTERRUPTIBLE; |
1596 | read_lock(&tasklist_lock); | |
1597 | tsk = current; | |
1598 | do { | |
98abed02 RM |
1599 | int tsk_result = do_wait_thread(tsk, &retval, |
1600 | type, pid, options, | |
1601 | infop, stat_addr, ru); | |
1602 | if (!tsk_result) | |
1603 | tsk_result = ptrace_do_wait(tsk, &retval, | |
1604 | type, pid, options, | |
1605 | infop, stat_addr, ru); | |
1606 | if (tsk_result) { | |
1607 | /* | |
1608 | * tasklist_lock is unlocked and we have a final result. | |
1609 | */ | |
1610 | retval = tsk_result; | |
1611 | goto end; | |
1da177e4 | 1612 | } |
98abed02 | 1613 | |
1da177e4 LT |
1614 | if (options & __WNOTHREAD) |
1615 | break; | |
1616 | tsk = next_thread(tsk); | |
125e1874 | 1617 | BUG_ON(tsk->signal != current->signal); |
1da177e4 | 1618 | } while (tsk != current); |
1da177e4 | 1619 | read_unlock(&tasklist_lock); |
f2cc3eb1 | 1620 | |
98abed02 | 1621 | if (!retval && !(options & WNOHANG)) { |
1da177e4 | 1622 | retval = -ERESTARTSYS; |
98abed02 RM |
1623 | if (!signal_pending(current)) { |
1624 | schedule(); | |
1625 | goto repeat; | |
1626 | } | |
1da177e4 | 1627 | } |
98abed02 | 1628 | |
1da177e4 LT |
1629 | end: |
1630 | current->state = TASK_RUNNING; | |
1631 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1632 | if (infop) { | |
1633 | if (retval > 0) | |
9cbab810 | 1634 | retval = 0; |
1da177e4 LT |
1635 | else { |
1636 | /* | |
1637 | * For a WNOHANG return, clear out all the fields | |
1638 | * we would set so the user can easily tell the | |
1639 | * difference. | |
1640 | */ | |
1641 | if (!retval) | |
1642 | retval = put_user(0, &infop->si_signo); | |
1643 | if (!retval) | |
1644 | retval = put_user(0, &infop->si_errno); | |
1645 | if (!retval) | |
1646 | retval = put_user(0, &infop->si_code); | |
1647 | if (!retval) | |
1648 | retval = put_user(0, &infop->si_pid); | |
1649 | if (!retval) | |
1650 | retval = put_user(0, &infop->si_uid); | |
1651 | if (!retval) | |
1652 | retval = put_user(0, &infop->si_status); | |
1653 | } | |
1654 | } | |
1655 | return retval; | |
1656 | } | |
1657 | ||
17da2bd9 HC |
1658 | SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, |
1659 | infop, int, options, struct rusage __user *, ru) | |
1da177e4 | 1660 | { |
161550d7 EB |
1661 | struct pid *pid = NULL; |
1662 | enum pid_type type; | |
1da177e4 LT |
1663 | long ret; |
1664 | ||
1665 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1666 | return -EINVAL; | |
1667 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1668 | return -EINVAL; | |
1669 | ||
1670 | switch (which) { | |
1671 | case P_ALL: | |
161550d7 | 1672 | type = PIDTYPE_MAX; |
1da177e4 LT |
1673 | break; |
1674 | case P_PID: | |
161550d7 EB |
1675 | type = PIDTYPE_PID; |
1676 | if (upid <= 0) | |
1da177e4 LT |
1677 | return -EINVAL; |
1678 | break; | |
1679 | case P_PGID: | |
161550d7 EB |
1680 | type = PIDTYPE_PGID; |
1681 | if (upid <= 0) | |
1da177e4 | 1682 | return -EINVAL; |
1da177e4 LT |
1683 | break; |
1684 | default: | |
1685 | return -EINVAL; | |
1686 | } | |
1687 | ||
161550d7 EB |
1688 | if (type < PIDTYPE_MAX) |
1689 | pid = find_get_pid(upid); | |
1690 | ret = do_wait(type, pid, options, infop, NULL, ru); | |
1691 | put_pid(pid); | |
1da177e4 LT |
1692 | |
1693 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1694 | asmlinkage_protect(5, ret, which, upid, infop, options, ru); |
1da177e4 LT |
1695 | return ret; |
1696 | } | |
1697 | ||
754fe8d2 HC |
1698 | SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, |
1699 | int, options, struct rusage __user *, ru) | |
1da177e4 | 1700 | { |
161550d7 EB |
1701 | struct pid *pid = NULL; |
1702 | enum pid_type type; | |
1da177e4 LT |
1703 | long ret; |
1704 | ||
1705 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1706 | __WNOTHREAD|__WCLONE|__WALL)) | |
1707 | return -EINVAL; | |
161550d7 EB |
1708 | |
1709 | if (upid == -1) | |
1710 | type = PIDTYPE_MAX; | |
1711 | else if (upid < 0) { | |
1712 | type = PIDTYPE_PGID; | |
1713 | pid = find_get_pid(-upid); | |
1714 | } else if (upid == 0) { | |
1715 | type = PIDTYPE_PGID; | |
2ae448ef | 1716 | pid = get_task_pid(current, PIDTYPE_PGID); |
161550d7 EB |
1717 | } else /* upid > 0 */ { |
1718 | type = PIDTYPE_PID; | |
1719 | pid = find_get_pid(upid); | |
1720 | } | |
1721 | ||
1722 | ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru); | |
1723 | put_pid(pid); | |
1da177e4 LT |
1724 | |
1725 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1726 | asmlinkage_protect(4, ret, upid, stat_addr, options, ru); |
1da177e4 LT |
1727 | return ret; |
1728 | } | |
1729 | ||
1730 | #ifdef __ARCH_WANT_SYS_WAITPID | |
1731 | ||
1732 | /* | |
1733 | * sys_waitpid() remains for compatibility. waitpid() should be | |
1734 | * implemented by calling sys_wait4() from libc.a. | |
1735 | */ | |
17da2bd9 | 1736 | SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options) |
1da177e4 LT |
1737 | { |
1738 | return sys_wait4(pid, stat_addr, options, NULL); | |
1739 | } | |
1740 | ||
1741 | #endif |