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> |
1da177e4 LT |
16 | #include <linux/key.h> |
17 | #include <linux/security.h> | |
18 | #include <linux/cpu.h> | |
19 | #include <linux/acct.h> | |
8f0ab514 | 20 | #include <linux/tsacct_kern.h> |
1da177e4 LT |
21 | #include <linux/file.h> |
22 | #include <linux/binfmts.h> | |
ab516013 | 23 | #include <linux/nsproxy.h> |
84d73786 | 24 | #include <linux/pid_namespace.h> |
1da177e4 LT |
25 | #include <linux/ptrace.h> |
26 | #include <linux/profile.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/proc_fs.h> | |
49d769d5 | 29 | #include <linux/kthread.h> |
1da177e4 | 30 | #include <linux/mempolicy.h> |
c757249a | 31 | #include <linux/taskstats_kern.h> |
ca74e92b | 32 | #include <linux/delayacct.h> |
83144186 | 33 | #include <linux/freezer.h> |
b4f48b63 | 34 | #include <linux/cgroup.h> |
1da177e4 | 35 | #include <linux/syscalls.h> |
7ed20e1a | 36 | #include <linux/signal.h> |
6a14c5c9 | 37 | #include <linux/posix-timers.h> |
9f46080c | 38 | #include <linux/cn_proc.h> |
de5097c2 | 39 | #include <linux/mutex.h> |
0771dfef | 40 | #include <linux/futex.h> |
34f192c6 | 41 | #include <linux/compat.h> |
b92ce558 | 42 | #include <linux/pipe_fs_i.h> |
fa84cb93 | 43 | #include <linux/audit.h> /* for audit_free() */ |
83cc5ed3 | 44 | #include <linux/resource.h> |
0d67a46d | 45 | #include <linux/blkdev.h> |
6eaeeaba | 46 | #include <linux/task_io_accounting_ops.h> |
1da177e4 LT |
47 | |
48 | #include <asm/uaccess.h> | |
49 | #include <asm/unistd.h> | |
50 | #include <asm/pgtable.h> | |
51 | #include <asm/mmu_context.h> | |
52 | ||
408b664a AB |
53 | static void exit_mm(struct task_struct * tsk); |
54 | ||
1da177e4 LT |
55 | static void __unhash_process(struct task_struct *p) |
56 | { | |
57 | nr_threads--; | |
58 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
59 | if (thread_group_leader(p)) { |
60 | detach_pid(p, PIDTYPE_PGID); | |
61 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 62 | |
5e85d4ab | 63 | list_del_rcu(&p->tasks); |
73b9ebfe | 64 | __get_cpu_var(process_counts)--; |
1da177e4 | 65 | } |
47e65328 | 66 | list_del_rcu(&p->thread_group); |
c97d9893 | 67 | remove_parent(p); |
1da177e4 LT |
68 | } |
69 | ||
6a14c5c9 ON |
70 | /* |
71 | * This function expects the tasklist_lock write-locked. | |
72 | */ | |
73 | static void __exit_signal(struct task_struct *tsk) | |
74 | { | |
75 | struct signal_struct *sig = tsk->signal; | |
76 | struct sighand_struct *sighand; | |
77 | ||
78 | BUG_ON(!sig); | |
79 | BUG_ON(!atomic_read(&sig->count)); | |
80 | ||
81 | rcu_read_lock(); | |
82 | sighand = rcu_dereference(tsk->sighand); | |
83 | spin_lock(&sighand->siglock); | |
84 | ||
85 | posix_cpu_timers_exit(tsk); | |
86 | if (atomic_dec_and_test(&sig->count)) | |
87 | posix_cpu_timers_exit_group(tsk); | |
88 | else { | |
89 | /* | |
90 | * If there is any task waiting for the group exit | |
91 | * then notify it: | |
92 | */ | |
6db840fa | 93 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) |
6a14c5c9 | 94 | wake_up_process(sig->group_exit_task); |
6db840fa | 95 | |
6a14c5c9 ON |
96 | if (tsk == sig->curr_target) |
97 | sig->curr_target = next_thread(tsk); | |
98 | /* | |
99 | * Accumulate here the counters for all threads but the | |
100 | * group leader as they die, so they can be added into | |
101 | * the process-wide totals when those are taken. | |
102 | * The group leader stays around as a zombie as long | |
103 | * as there are other threads. When it gets reaped, | |
104 | * the exit.c code will add its counts into these totals. | |
105 | * We won't ever get here for the group leader, since it | |
106 | * will have been the last reference on the signal_struct. | |
107 | */ | |
108 | sig->utime = cputime_add(sig->utime, tsk->utime); | |
109 | sig->stime = cputime_add(sig->stime, tsk->stime); | |
9ac52315 | 110 | sig->gtime = cputime_add(sig->gtime, tsk->gtime); |
6a14c5c9 ON |
111 | sig->min_flt += tsk->min_flt; |
112 | sig->maj_flt += tsk->maj_flt; | |
113 | sig->nvcsw += tsk->nvcsw; | |
114 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
115 | sig->inblock += task_io_get_inblock(tsk); |
116 | sig->oublock += task_io_get_oublock(tsk); | |
172ba844 | 117 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
6a14c5c9 ON |
118 | sig = NULL; /* Marker for below. */ |
119 | } | |
120 | ||
5876700c ON |
121 | __unhash_process(tsk); |
122 | ||
6a14c5c9 | 123 | tsk->signal = NULL; |
a7e5328a | 124 | tsk->sighand = NULL; |
6a14c5c9 ON |
125 | spin_unlock(&sighand->siglock); |
126 | rcu_read_unlock(); | |
127 | ||
a7e5328a | 128 | __cleanup_sighand(sighand); |
6a14c5c9 ON |
129 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
130 | flush_sigqueue(&tsk->pending); | |
131 | if (sig) { | |
132 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 133 | taskstats_tgid_free(sig); |
6a14c5c9 ON |
134 | __cleanup_signal(sig); |
135 | } | |
136 | } | |
137 | ||
8c7904a0 EB |
138 | static void delayed_put_task_struct(struct rcu_head *rhp) |
139 | { | |
140 | put_task_struct(container_of(rhp, struct task_struct, rcu)); | |
141 | } | |
142 | ||
1da177e4 LT |
143 | void release_task(struct task_struct * p) |
144 | { | |
36c8b586 | 145 | struct task_struct *leader; |
1da177e4 | 146 | int zap_leader; |
1f09f974 | 147 | repeat: |
1da177e4 | 148 | atomic_dec(&p->user->processes); |
60347f67 | 149 | proc_flush_task(p); |
1da177e4 | 150 | write_lock_irq(&tasklist_lock); |
1f09f974 | 151 | ptrace_unlink(p); |
1da177e4 LT |
152 | BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); |
153 | __exit_signal(p); | |
35f5cad8 | 154 | |
1da177e4 LT |
155 | /* |
156 | * If we are the last non-leader member of the thread | |
157 | * group, and the leader is zombie, then notify the | |
158 | * group leader's parent process. (if it wants notification.) | |
159 | */ | |
160 | zap_leader = 0; | |
161 | leader = p->group_leader; | |
162 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
163 | BUG_ON(leader->exit_signal == -1); | |
164 | do_notify_parent(leader, leader->exit_signal); | |
165 | /* | |
166 | * If we were the last child thread and the leader has | |
167 | * exited already, and the leader's parent ignores SIGCHLD, | |
168 | * then we are the one who should release the leader. | |
169 | * | |
170 | * do_notify_parent() will have marked it self-reaping in | |
171 | * that case. | |
172 | */ | |
173 | zap_leader = (leader->exit_signal == -1); | |
174 | } | |
175 | ||
1da177e4 | 176 | write_unlock_irq(&tasklist_lock); |
1da177e4 | 177 | release_thread(p); |
8c7904a0 | 178 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
179 | |
180 | p = leader; | |
181 | if (unlikely(zap_leader)) | |
182 | goto repeat; | |
183 | } | |
184 | ||
1da177e4 LT |
185 | /* |
186 | * This checks not only the pgrp, but falls back on the pid if no | |
187 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
188 | * without this... | |
04a2e6a5 EB |
189 | * |
190 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 191 | */ |
04a2e6a5 | 192 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
193 | { |
194 | struct task_struct *p; | |
04a2e6a5 | 195 | struct pid *sid = NULL; |
62dfb554 | 196 | |
04a2e6a5 | 197 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 198 | if (p == NULL) |
04a2e6a5 | 199 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 200 | if (p != NULL) |
04a2e6a5 | 201 | sid = task_session(p); |
62dfb554 | 202 | |
1da177e4 LT |
203 | return sid; |
204 | } | |
205 | ||
206 | /* | |
207 | * Determine if a process group is "orphaned", according to the POSIX | |
208 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
209 | * by terminal-generated stop signals. Newly orphaned process groups are | |
210 | * to receive a SIGHUP and a SIGCONT. | |
211 | * | |
212 | * "I ask you, have you ever known what it is to be an orphan?" | |
213 | */ | |
0475ac08 | 214 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
215 | { |
216 | struct task_struct *p; | |
217 | int ret = 1; | |
218 | ||
0475ac08 | 219 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
220 | if (p == ignored_task |
221 | || p->exit_state | |
b460cbc5 | 222 | || is_global_init(p->real_parent)) |
1da177e4 | 223 | continue; |
0475ac08 EB |
224 | if (task_pgrp(p->real_parent) != pgrp && |
225 | task_session(p->real_parent) == task_session(p)) { | |
1da177e4 LT |
226 | ret = 0; |
227 | break; | |
228 | } | |
0475ac08 | 229 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
230 | return ret; /* (sighing) "Often!" */ |
231 | } | |
232 | ||
3e7cd6c4 | 233 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
234 | { |
235 | int retval; | |
236 | ||
237 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 238 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
239 | read_unlock(&tasklist_lock); |
240 | ||
241 | return retval; | |
242 | } | |
243 | ||
0475ac08 | 244 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
245 | { |
246 | int retval = 0; | |
247 | struct task_struct *p; | |
248 | ||
0475ac08 | 249 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
338077e5 | 250 | if (!task_is_stopped(p)) |
1da177e4 | 251 | continue; |
1da177e4 LT |
252 | retval = 1; |
253 | break; | |
0475ac08 | 254 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
255 | return retval; |
256 | } | |
257 | ||
258 | /** | |
49d769d5 | 259 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
260 | * |
261 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
262 | * it ever exits, it should generally reparent itself to kthreadd so it |
263 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
264 | * |
265 | * The various task state such as scheduling policy and priority may have | |
266 | * been inherited from a user process, so we reset them to sane values here. | |
267 | * | |
49d769d5 | 268 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 269 | */ |
49d769d5 | 270 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
271 | { |
272 | write_lock_irq(&tasklist_lock); | |
273 | ||
274 | ptrace_unlink(current); | |
275 | /* Reparent to init */ | |
9b678ece | 276 | remove_parent(current); |
49d769d5 | 277 | current->real_parent = current->parent = kthreadd_task; |
9b678ece | 278 | add_parent(current); |
1da177e4 LT |
279 | |
280 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
281 | current->exit_signal = SIGCHLD; | |
282 | ||
e05606d3 | 283 | if (task_nice(current) < 0) |
1da177e4 LT |
284 | set_user_nice(current, 0); |
285 | /* cpus_allowed? */ | |
286 | /* rt_priority? */ | |
287 | /* signals? */ | |
288 | security_task_reparent_to_init(current); | |
289 | memcpy(current->signal->rlim, init_task.signal->rlim, | |
290 | sizeof(current->signal->rlim)); | |
291 | atomic_inc(&(INIT_USER->__count)); | |
292 | write_unlock_irq(&tasklist_lock); | |
293 | switch_uid(INIT_USER); | |
294 | } | |
295 | ||
296 | void __set_special_pids(pid_t session, pid_t pgrp) | |
297 | { | |
e19f247a | 298 | struct task_struct *curr = current->group_leader; |
1da177e4 | 299 | |
a47afb0f | 300 | if (task_session_nr(curr) != session) { |
1da177e4 | 301 | detach_pid(curr, PIDTYPE_SID); |
a47afb0f | 302 | set_task_session(curr, session); |
e713d0da | 303 | attach_pid(curr, PIDTYPE_SID, find_pid(session)); |
1da177e4 | 304 | } |
a47afb0f | 305 | if (task_pgrp_nr(curr) != pgrp) { |
1da177e4 | 306 | detach_pid(curr, PIDTYPE_PGID); |
9a2e7057 | 307 | set_task_pgrp(curr, pgrp); |
e713d0da | 308 | attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp)); |
1da177e4 LT |
309 | } |
310 | } | |
311 | ||
ae424ae4 | 312 | static void set_special_pids(pid_t session, pid_t pgrp) |
1da177e4 LT |
313 | { |
314 | write_lock_irq(&tasklist_lock); | |
315 | __set_special_pids(session, pgrp); | |
316 | write_unlock_irq(&tasklist_lock); | |
317 | } | |
318 | ||
319 | /* | |
320 | * Let kernel threads use this to say that they | |
321 | * allow a certain signal (since daemonize() will | |
322 | * have disabled all of them by default). | |
323 | */ | |
324 | int allow_signal(int sig) | |
325 | { | |
7ed20e1a | 326 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
327 | return -EINVAL; |
328 | ||
329 | spin_lock_irq(¤t->sighand->siglock); | |
330 | sigdelset(¤t->blocked, sig); | |
331 | if (!current->mm) { | |
332 | /* Kernel threads handle their own signals. | |
333 | Let the signal code know it'll be handled, so | |
334 | that they don't get converted to SIGKILL or | |
335 | just silently dropped */ | |
336 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
337 | } | |
338 | recalc_sigpending(); | |
339 | spin_unlock_irq(¤t->sighand->siglock); | |
340 | return 0; | |
341 | } | |
342 | ||
343 | EXPORT_SYMBOL(allow_signal); | |
344 | ||
345 | int disallow_signal(int sig) | |
346 | { | |
7ed20e1a | 347 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
348 | return -EINVAL; |
349 | ||
350 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 351 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
352 | recalc_sigpending(); |
353 | spin_unlock_irq(¤t->sighand->siglock); | |
354 | return 0; | |
355 | } | |
356 | ||
357 | EXPORT_SYMBOL(disallow_signal); | |
358 | ||
359 | /* | |
360 | * Put all the gunge required to become a kernel thread without | |
361 | * attached user resources in one place where it belongs. | |
362 | */ | |
363 | ||
364 | void daemonize(const char *name, ...) | |
365 | { | |
366 | va_list args; | |
367 | struct fs_struct *fs; | |
368 | sigset_t blocked; | |
369 | ||
370 | va_start(args, name); | |
371 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
372 | va_end(args); | |
373 | ||
374 | /* | |
375 | * If we were started as result of loading a module, close all of the | |
376 | * user space pages. We don't need them, and if we didn't close them | |
377 | * they would be locked into memory. | |
378 | */ | |
379 | exit_mm(current); | |
83144186 RW |
380 | /* |
381 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
382 | * or suspend transition begins right now. | |
383 | */ | |
384 | current->flags |= PF_NOFREEZE; | |
1da177e4 LT |
385 | |
386 | set_special_pids(1, 1); | |
24ec839c | 387 | proc_clear_tty(current); |
1da177e4 LT |
388 | |
389 | /* Block and flush all signals */ | |
390 | sigfillset(&blocked); | |
391 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
392 | flush_signals(current); | |
393 | ||
394 | /* Become as one with the init task */ | |
395 | ||
396 | exit_fs(current); /* current->fs->count--; */ | |
397 | fs = init_task.fs; | |
398 | current->fs = fs; | |
399 | atomic_inc(&fs->count); | |
ab516013 | 400 | |
cf7b708c PE |
401 | if (current->nsproxy != init_task.nsproxy) { |
402 | get_nsproxy(init_task.nsproxy); | |
403 | switch_task_namespaces(current, init_task.nsproxy); | |
404 | } | |
ab516013 | 405 | |
d4c5e41f | 406 | exit_files(current); |
1da177e4 LT |
407 | current->files = init_task.files; |
408 | atomic_inc(¤t->files->count); | |
409 | ||
49d769d5 | 410 | reparent_to_kthreadd(); |
1da177e4 LT |
411 | } |
412 | ||
413 | EXPORT_SYMBOL(daemonize); | |
414 | ||
858119e1 | 415 | static void close_files(struct files_struct * files) |
1da177e4 LT |
416 | { |
417 | int i, j; | |
badf1662 | 418 | struct fdtable *fdt; |
1da177e4 LT |
419 | |
420 | j = 0; | |
4fb3a538 DS |
421 | |
422 | /* | |
423 | * It is safe to dereference the fd table without RCU or | |
424 | * ->file_lock because this is the last reference to the | |
425 | * files structure. | |
426 | */ | |
badf1662 | 427 | fdt = files_fdtable(files); |
1da177e4 LT |
428 | for (;;) { |
429 | unsigned long set; | |
430 | i = j * __NFDBITS; | |
bbea9f69 | 431 | if (i >= fdt->max_fds) |
1da177e4 | 432 | break; |
badf1662 | 433 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
434 | while (set) { |
435 | if (set & 1) { | |
badf1662 | 436 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 437 | if (file) { |
1da177e4 | 438 | filp_close(file, files); |
944be0b2 IM |
439 | cond_resched(); |
440 | } | |
1da177e4 LT |
441 | } |
442 | i++; | |
443 | set >>= 1; | |
444 | } | |
445 | } | |
446 | } | |
447 | ||
448 | struct files_struct *get_files_struct(struct task_struct *task) | |
449 | { | |
450 | struct files_struct *files; | |
451 | ||
452 | task_lock(task); | |
453 | files = task->files; | |
454 | if (files) | |
455 | atomic_inc(&files->count); | |
456 | task_unlock(task); | |
457 | ||
458 | return files; | |
459 | } | |
460 | ||
461 | void fastcall put_files_struct(struct files_struct *files) | |
462 | { | |
badf1662 DS |
463 | struct fdtable *fdt; |
464 | ||
1da177e4 LT |
465 | if (atomic_dec_and_test(&files->count)) { |
466 | close_files(files); | |
467 | /* | |
468 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
469 | * If the fdtable was embedded, pass files for freeing |
470 | * at the end of the RCU grace period. Otherwise, | |
471 | * you can free files immediately. | |
1da177e4 | 472 | */ |
badf1662 | 473 | fdt = files_fdtable(files); |
4fd45812 | 474 | if (fdt != &files->fdtab) |
ab2af1f5 | 475 | kmem_cache_free(files_cachep, files); |
01b2d93c | 476 | free_fdtable(fdt); |
1da177e4 LT |
477 | } |
478 | } | |
479 | ||
480 | EXPORT_SYMBOL(put_files_struct); | |
481 | ||
3b9b8ab6 KK |
482 | void reset_files_struct(struct task_struct *tsk, struct files_struct *files) |
483 | { | |
484 | struct files_struct *old; | |
485 | ||
486 | old = tsk->files; | |
487 | task_lock(tsk); | |
488 | tsk->files = files; | |
489 | task_unlock(tsk); | |
490 | put_files_struct(old); | |
491 | } | |
492 | EXPORT_SYMBOL(reset_files_struct); | |
493 | ||
a39bc516 | 494 | static void __exit_files(struct task_struct *tsk) |
1da177e4 LT |
495 | { |
496 | struct files_struct * files = tsk->files; | |
497 | ||
498 | if (files) { | |
499 | task_lock(tsk); | |
500 | tsk->files = NULL; | |
501 | task_unlock(tsk); | |
502 | put_files_struct(files); | |
503 | } | |
504 | } | |
505 | ||
506 | void exit_files(struct task_struct *tsk) | |
507 | { | |
508 | __exit_files(tsk); | |
509 | } | |
510 | ||
a39bc516 | 511 | static void __put_fs_struct(struct fs_struct *fs) |
1da177e4 LT |
512 | { |
513 | /* No need to hold fs->lock if we are killing it */ | |
514 | if (atomic_dec_and_test(&fs->count)) { | |
515 | dput(fs->root); | |
516 | mntput(fs->rootmnt); | |
517 | dput(fs->pwd); | |
518 | mntput(fs->pwdmnt); | |
519 | if (fs->altroot) { | |
520 | dput(fs->altroot); | |
521 | mntput(fs->altrootmnt); | |
522 | } | |
523 | kmem_cache_free(fs_cachep, fs); | |
524 | } | |
525 | } | |
526 | ||
527 | void put_fs_struct(struct fs_struct *fs) | |
528 | { | |
529 | __put_fs_struct(fs); | |
530 | } | |
531 | ||
a39bc516 | 532 | static void __exit_fs(struct task_struct *tsk) |
1da177e4 LT |
533 | { |
534 | struct fs_struct * fs = tsk->fs; | |
535 | ||
536 | if (fs) { | |
537 | task_lock(tsk); | |
538 | tsk->fs = NULL; | |
539 | task_unlock(tsk); | |
540 | __put_fs_struct(fs); | |
541 | } | |
542 | } | |
543 | ||
544 | void exit_fs(struct task_struct *tsk) | |
545 | { | |
546 | __exit_fs(tsk); | |
547 | } | |
548 | ||
549 | EXPORT_SYMBOL_GPL(exit_fs); | |
550 | ||
551 | /* | |
552 | * Turn us into a lazy TLB process if we | |
553 | * aren't already.. | |
554 | */ | |
408b664a | 555 | static void exit_mm(struct task_struct * tsk) |
1da177e4 LT |
556 | { |
557 | struct mm_struct *mm = tsk->mm; | |
558 | ||
559 | mm_release(tsk, mm); | |
560 | if (!mm) | |
561 | return; | |
562 | /* | |
563 | * Serialize with any possible pending coredump. | |
564 | * We must hold mmap_sem around checking core_waiters | |
565 | * and clearing tsk->mm. The core-inducing thread | |
566 | * will increment core_waiters for each thread in the | |
567 | * group with ->mm != NULL. | |
568 | */ | |
569 | down_read(&mm->mmap_sem); | |
570 | if (mm->core_waiters) { | |
571 | up_read(&mm->mmap_sem); | |
572 | down_write(&mm->mmap_sem); | |
573 | if (!--mm->core_waiters) | |
574 | complete(mm->core_startup_done); | |
575 | up_write(&mm->mmap_sem); | |
576 | ||
577 | wait_for_completion(&mm->core_done); | |
578 | down_read(&mm->mmap_sem); | |
579 | } | |
580 | atomic_inc(&mm->mm_count); | |
125e1874 | 581 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
582 | /* more a memory barrier than a real lock */ |
583 | task_lock(tsk); | |
584 | tsk->mm = NULL; | |
585 | up_read(&mm->mmap_sem); | |
586 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
587 | /* We don't want this task to be frozen prematurely */ |
588 | clear_freeze_flag(tsk); | |
1da177e4 LT |
589 | task_unlock(tsk); |
590 | mmput(mm); | |
591 | } | |
592 | ||
36c8b586 IM |
593 | static void |
594 | reparent_thread(struct task_struct *p, struct task_struct *father, int traced) | |
1da177e4 | 595 | { |
241ceee0 ON |
596 | if (p->pdeath_signal) |
597 | /* We already hold the tasklist_lock here. */ | |
598 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
599 | ||
1da177e4 LT |
600 | /* Move the child from its dying parent to the new one. */ |
601 | if (unlikely(traced)) { | |
602 | /* Preserve ptrace links if someone else is tracing this child. */ | |
603 | list_del_init(&p->ptrace_list); | |
604 | if (p->parent != p->real_parent) | |
605 | list_add(&p->ptrace_list, &p->real_parent->ptrace_children); | |
606 | } else { | |
607 | /* If this child is being traced, then we're the one tracing it | |
608 | * anyway, so let go of it. | |
609 | */ | |
610 | p->ptrace = 0; | |
6ac781b1 | 611 | remove_parent(p); |
1da177e4 | 612 | p->parent = p->real_parent; |
6ac781b1 | 613 | add_parent(p); |
1da177e4 | 614 | |
338077e5 | 615 | if (task_is_traced(p)) { |
1da177e4 LT |
616 | /* |
617 | * If it was at a trace stop, turn it into | |
618 | * a normal stop since it's no longer being | |
619 | * traced. | |
620 | */ | |
621 | ptrace_untrace(p); | |
622 | } | |
623 | } | |
624 | ||
b2b2cbc4 EB |
625 | /* If this is a threaded reparent there is no need to |
626 | * notify anyone anything has happened. | |
627 | */ | |
628 | if (p->real_parent->group_leader == father->group_leader) | |
629 | return; | |
630 | ||
631 | /* We don't want people slaying init. */ | |
632 | if (p->exit_signal != -1) | |
633 | p->exit_signal = SIGCHLD; | |
b2b2cbc4 EB |
634 | |
635 | /* If we'd notified the old parent about this child's death, | |
636 | * also notify the new parent. | |
637 | */ | |
638 | if (!traced && p->exit_state == EXIT_ZOMBIE && | |
639 | p->exit_signal != -1 && thread_group_empty(p)) | |
640 | do_notify_parent(p, p->exit_signal); | |
641 | ||
1da177e4 LT |
642 | /* |
643 | * process group orphan check | |
644 | * Case ii: Our child is in a different pgrp | |
645 | * than we are, and it was the only connection | |
646 | * outside, so the child pgrp is now orphaned. | |
647 | */ | |
0475ac08 EB |
648 | if ((task_pgrp(p) != task_pgrp(father)) && |
649 | (task_session(p) == task_session(father))) { | |
650 | struct pid *pgrp = task_pgrp(p); | |
1da177e4 | 651 | |
937949d9 CLG |
652 | if (will_become_orphaned_pgrp(pgrp, NULL) && |
653 | has_stopped_jobs(pgrp)) { | |
0475ac08 EB |
654 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); |
655 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
1da177e4 LT |
656 | } |
657 | } | |
658 | } | |
659 | ||
660 | /* | |
661 | * When we die, we re-parent all our children. | |
662 | * Try to give them to another thread in our thread | |
663 | * group, and if no such member exists, give it to | |
84d73786 SB |
664 | * the child reaper process (ie "init") in our pid |
665 | * space. | |
1da177e4 | 666 | */ |
762a24be | 667 | static void forget_original_parent(struct task_struct *father) |
1da177e4 | 668 | { |
03ff1797 | 669 | struct task_struct *p, *n, *reaper = father; |
762a24be ON |
670 | struct list_head ptrace_dead; |
671 | ||
672 | INIT_LIST_HEAD(&ptrace_dead); | |
673 | ||
674 | write_lock_irq(&tasklist_lock); | |
1da177e4 LT |
675 | |
676 | do { | |
677 | reaper = next_thread(reaper); | |
678 | if (reaper == father) { | |
88f21d81 | 679 | reaper = task_child_reaper(father); |
1da177e4 LT |
680 | break; |
681 | } | |
762a24be | 682 | } while (reaper->flags & PF_EXITING); |
1da177e4 LT |
683 | |
684 | /* | |
685 | * There are only two places where our children can be: | |
686 | * | |
687 | * - in our child list | |
688 | * - in our ptraced child list | |
689 | * | |
690 | * Search them and reparent children. | |
691 | */ | |
03ff1797 | 692 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
1da177e4 | 693 | int ptrace; |
1da177e4 LT |
694 | |
695 | ptrace = p->ptrace; | |
696 | ||
697 | /* if father isn't the real parent, then ptrace must be enabled */ | |
698 | BUG_ON(father != p->real_parent && !ptrace); | |
699 | ||
700 | if (father == p->real_parent) { | |
701 | /* reparent with a reaper, real father it's us */ | |
84eb646b | 702 | p->real_parent = reaper; |
1da177e4 LT |
703 | reparent_thread(p, father, 0); |
704 | } else { | |
705 | /* reparent ptraced task to its real parent */ | |
706 | __ptrace_unlink (p); | |
707 | if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 && | |
708 | thread_group_empty(p)) | |
709 | do_notify_parent(p, p->exit_signal); | |
710 | } | |
711 | ||
712 | /* | |
713 | * if the ptraced child is a zombie with exit_signal == -1 | |
714 | * we must collect it before we exit, or it will remain | |
715 | * zombie forever since we prevented it from self-reap itself | |
716 | * while it was being traced by us, to be able to see it in wait4. | |
717 | */ | |
718 | if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1)) | |
762a24be | 719 | list_add(&p->ptrace_list, &ptrace_dead); |
1da177e4 | 720 | } |
762a24be | 721 | |
03ff1797 | 722 | list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) { |
84eb646b | 723 | p->real_parent = reaper; |
1da177e4 LT |
724 | reparent_thread(p, father, 1); |
725 | } | |
762a24be ON |
726 | |
727 | write_unlock_irq(&tasklist_lock); | |
728 | BUG_ON(!list_empty(&father->children)); | |
729 | BUG_ON(!list_empty(&father->ptrace_children)); | |
730 | ||
731 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_list) { | |
732 | list_del_init(&p->ptrace_list); | |
733 | release_task(p); | |
734 | } | |
735 | ||
1da177e4 LT |
736 | } |
737 | ||
738 | /* | |
739 | * Send signals to all our closest relatives so that they know | |
740 | * to properly mourn us.. | |
741 | */ | |
742 | static void exit_notify(struct task_struct *tsk) | |
743 | { | |
744 | int state; | |
745 | struct task_struct *t; | |
0475ac08 | 746 | struct pid *pgrp; |
1da177e4 LT |
747 | |
748 | if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT) | |
749 | && !thread_group_empty(tsk)) { | |
750 | /* | |
751 | * This occurs when there was a race between our exit | |
752 | * syscall and a group signal choosing us as the one to | |
753 | * wake up. It could be that we are the only thread | |
754 | * alerted to check for pending signals, but another thread | |
755 | * should be woken now to take the signal since we will not. | |
756 | * Now we'll wake all the threads in the group just to make | |
757 | * sure someone gets all the pending signals. | |
758 | */ | |
1da177e4 LT |
759 | spin_lock_irq(&tsk->sighand->siglock); |
760 | for (t = next_thread(tsk); t != tsk; t = next_thread(t)) | |
7bb44ade RM |
761 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) |
762 | recalc_sigpending_and_wake(t); | |
1da177e4 | 763 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
764 | } |
765 | ||
1da177e4 LT |
766 | /* |
767 | * This does two things: | |
768 | * | |
769 | * A. Make init inherit all the child processes | |
770 | * B. Check to see if any process groups have become orphaned | |
771 | * as a result of our exiting, and if they have any stopped | |
772 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
773 | */ | |
762a24be | 774 | forget_original_parent(tsk); |
2e4a7072 | 775 | exit_task_namespaces(tsk); |
1da177e4 | 776 | |
762a24be | 777 | write_lock_irq(&tasklist_lock); |
1da177e4 LT |
778 | /* |
779 | * Check to see if any process groups have become orphaned | |
780 | * as a result of our exiting, and if they have any stopped | |
781 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
782 | * | |
783 | * Case i: Our father is in a different pgrp than we are | |
784 | * and we were the only connection outside, so our pgrp | |
785 | * is about to become orphaned. | |
786 | */ | |
1da177e4 | 787 | t = tsk->real_parent; |
3ae4cbad | 788 | |
0475ac08 EB |
789 | pgrp = task_pgrp(tsk); |
790 | if ((task_pgrp(t) != pgrp) && | |
14e9d573 | 791 | (task_session(t) == task_session(tsk)) && |
0475ac08 EB |
792 | will_become_orphaned_pgrp(pgrp, tsk) && |
793 | has_stopped_jobs(pgrp)) { | |
794 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
795 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
1da177e4 LT |
796 | } |
797 | ||
24728448 | 798 | /* Let father know we died |
1da177e4 LT |
799 | * |
800 | * Thread signals are configurable, but you aren't going to use | |
d4c5e41f | 801 | * that to send signals to arbitary processes. |
1da177e4 LT |
802 | * That stops right now. |
803 | * | |
804 | * If the parent exec id doesn't match the exec id we saved | |
805 | * when we started then we know the parent has changed security | |
806 | * domain. | |
807 | * | |
808 | * If our self_exec id doesn't match our parent_exec_id then | |
809 | * we have changed execution domain as these two values started | |
810 | * the same after a fork. | |
1da177e4 | 811 | */ |
1da177e4 LT |
812 | if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 && |
813 | ( tsk->parent_exec_id != t->self_exec_id || | |
814 | tsk->self_exec_id != tsk->parent_exec_id) | |
815 | && !capable(CAP_KILL)) | |
816 | tsk->exit_signal = SIGCHLD; | |
817 | ||
818 | ||
819 | /* If something other than our normal parent is ptracing us, then | |
820 | * send it a SIGCHLD instead of honoring exit_signal. exit_signal | |
821 | * only has special meaning to our real parent. | |
822 | */ | |
823 | if (tsk->exit_signal != -1 && thread_group_empty(tsk)) { | |
824 | int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD; | |
825 | do_notify_parent(tsk, signal); | |
826 | } else if (tsk->ptrace) { | |
827 | do_notify_parent(tsk, SIGCHLD); | |
828 | } | |
829 | ||
830 | state = EXIT_ZOMBIE; | |
24728448 | 831 | if (tsk->exit_signal == -1 && likely(!tsk->ptrace)) |
1da177e4 LT |
832 | state = EXIT_DEAD; |
833 | tsk->exit_state = state; | |
834 | ||
6db840fa ON |
835 | if (thread_group_leader(tsk) && |
836 | tsk->signal->notify_count < 0 && | |
837 | tsk->signal->group_exit_task) | |
838 | wake_up_process(tsk->signal->group_exit_task); | |
839 | ||
1da177e4 LT |
840 | write_unlock_irq(&tasklist_lock); |
841 | ||
1da177e4 LT |
842 | /* If the process is dead, release it - nobody will wait for it */ |
843 | if (state == EXIT_DEAD) | |
844 | release_task(tsk); | |
1da177e4 LT |
845 | } |
846 | ||
e18eecb8 JD |
847 | #ifdef CONFIG_DEBUG_STACK_USAGE |
848 | static void check_stack_usage(void) | |
849 | { | |
850 | static DEFINE_SPINLOCK(low_water_lock); | |
851 | static int lowest_to_date = THREAD_SIZE; | |
852 | unsigned long *n = end_of_stack(current); | |
853 | unsigned long free; | |
854 | ||
855 | while (*n == 0) | |
856 | n++; | |
857 | free = (unsigned long)n - (unsigned long)end_of_stack(current); | |
858 | ||
859 | if (free >= lowest_to_date) | |
860 | return; | |
861 | ||
862 | spin_lock(&low_water_lock); | |
863 | if (free < lowest_to_date) { | |
864 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
865 | "left\n", | |
866 | current->comm, free); | |
867 | lowest_to_date = free; | |
868 | } | |
869 | spin_unlock(&low_water_lock); | |
870 | } | |
871 | #else | |
872 | static inline void check_stack_usage(void) {} | |
873 | #endif | |
874 | ||
84eb646b ON |
875 | static inline void exit_child_reaper(struct task_struct *tsk) |
876 | { | |
88f21d81 | 877 | if (likely(tsk->group_leader != task_child_reaper(tsk))) |
84eb646b ON |
878 | return; |
879 | ||
3eb07c8c SB |
880 | if (tsk->nsproxy->pid_ns == &init_pid_ns) |
881 | panic("Attempted to kill init!"); | |
882 | ||
883 | /* | |
884 | * @tsk is the last thread in the 'cgroup-init' and is exiting. | |
885 | * Terminate all remaining processes in the namespace and reap them | |
886 | * before exiting @tsk. | |
887 | * | |
888 | * Note that @tsk (last thread of cgroup-init) may not necessarily | |
889 | * be the child-reaper (i.e main thread of cgroup-init) of the | |
890 | * namespace i.e the child_reaper may have already exited. | |
891 | * | |
892 | * Even after a child_reaper exits, we let it inherit orphaned children, | |
893 | * because, pid_ns->child_reaper remains valid as long as there is | |
894 | * at least one living sub-thread in the cgroup init. | |
895 | ||
896 | * This living sub-thread of the cgroup-init will be notified when | |
897 | * a child inherited by the 'child-reaper' exits (do_notify_parent() | |
898 | * uses __group_send_sig_info()). Further, when reaping child processes, | |
899 | * do_wait() iterates over children of all living sub threads. | |
900 | ||
901 | * i.e even though 'child_reaper' thread is listed as the parent of the | |
902 | * orphaned children, any living sub-thread in the cgroup-init can | |
903 | * perform the role of the child_reaper. | |
904 | */ | |
905 | zap_pid_ns_processes(tsk->nsproxy->pid_ns); | |
84eb646b ON |
906 | } |
907 | ||
1da177e4 LT |
908 | fastcall NORET_TYPE void do_exit(long code) |
909 | { | |
910 | struct task_struct *tsk = current; | |
911 | int group_dead; | |
912 | ||
913 | profile_task_exit(tsk); | |
914 | ||
22e2c507 JA |
915 | WARN_ON(atomic_read(&tsk->fs_excl)); |
916 | ||
1da177e4 LT |
917 | if (unlikely(in_interrupt())) |
918 | panic("Aiee, killing interrupt handler!"); | |
919 | if (unlikely(!tsk->pid)) | |
920 | panic("Attempted to kill the idle task!"); | |
1da177e4 LT |
921 | |
922 | if (unlikely(current->ptrace & PT_TRACE_EXIT)) { | |
923 | current->ptrace_message = code; | |
924 | ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); | |
925 | } | |
926 | ||
df164db5 AN |
927 | /* |
928 | * We're taking recursive faults here in do_exit. Safest is to just | |
929 | * leave this task alone and wait for reboot. | |
930 | */ | |
931 | if (unlikely(tsk->flags & PF_EXITING)) { | |
932 | printk(KERN_ALERT | |
933 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
934 | /* |
935 | * We can do this unlocked here. The futex code uses | |
936 | * this flag just to verify whether the pi state | |
937 | * cleanup has been done or not. In the worst case it | |
938 | * loops once more. We pretend that the cleanup was | |
939 | * done as there is no way to return. Either the | |
940 | * OWNER_DIED bit is set by now or we push the blocked | |
941 | * task into the wait for ever nirwana as well. | |
942 | */ | |
943 | tsk->flags |= PF_EXITPIDONE; | |
afc847b7 AV |
944 | if (tsk->io_context) |
945 | exit_io_context(); | |
df164db5 AN |
946 | set_current_state(TASK_UNINTERRUPTIBLE); |
947 | schedule(); | |
948 | } | |
949 | ||
d2ee7198 | 950 | tsk->flags |= PF_EXITING; |
778e9a9c AK |
951 | /* |
952 | * tsk->flags are checked in the futex code to protect against | |
953 | * an exiting task cleaning up the robust pi futexes. | |
954 | */ | |
d2ee7198 ON |
955 | smp_mb(); |
956 | spin_unlock_wait(&tsk->pi_lock); | |
1da177e4 | 957 | |
1da177e4 LT |
958 | if (unlikely(in_atomic())) |
959 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
ba25f9dc | 960 | current->comm, task_pid_nr(current), |
1da177e4 LT |
961 | preempt_count()); |
962 | ||
963 | acct_update_integrals(tsk); | |
365e9c87 HD |
964 | if (tsk->mm) { |
965 | update_hiwater_rss(tsk->mm); | |
966 | update_hiwater_vm(tsk->mm); | |
967 | } | |
1da177e4 | 968 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 969 | if (group_dead) { |
84eb646b | 970 | exit_child_reaper(tsk); |
778e9a9c | 971 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 972 | exit_itimers(tsk->signal); |
c3068951 | 973 | } |
f6ec29a4 | 974 | acct_collect(code, group_dead); |
42b2dd0a | 975 | #ifdef CONFIG_FUTEX |
0771dfef IM |
976 | if (unlikely(tsk->robust_list)) |
977 | exit_robust_list(tsk); | |
42b2dd0a | 978 | #ifdef CONFIG_COMPAT |
34f192c6 IM |
979 | if (unlikely(tsk->compat_robust_list)) |
980 | compat_exit_robust_list(tsk); | |
42b2dd0a | 981 | #endif |
34f192c6 | 982 | #endif |
522ed776 MT |
983 | if (group_dead) |
984 | tty_audit_exit(); | |
fa84cb93 AV |
985 | if (unlikely(tsk->audit_context)) |
986 | audit_free(tsk); | |
115085ea | 987 | |
f2ab6d88 | 988 | tsk->exit_code = code; |
115085ea | 989 | taskstats_exit(tsk, group_dead); |
c757249a | 990 | |
1da177e4 LT |
991 | exit_mm(tsk); |
992 | ||
0e464814 | 993 | if (group_dead) |
f6ec29a4 | 994 | acct_process(); |
1da177e4 LT |
995 | exit_sem(tsk); |
996 | __exit_files(tsk); | |
997 | __exit_fs(tsk); | |
e18eecb8 | 998 | check_stack_usage(); |
1da177e4 | 999 | exit_thread(); |
b4f48b63 | 1000 | cgroup_exit(tsk, 1); |
1da177e4 LT |
1001 | exit_keys(tsk); |
1002 | ||
1003 | if (group_dead && tsk->signal->leader) | |
1004 | disassociate_ctty(1); | |
1005 | ||
a1261f54 | 1006 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
1007 | if (tsk->binfmt) |
1008 | module_put(tsk->binfmt->module); | |
1009 | ||
9f46080c | 1010 | proc_exit_connector(tsk); |
0f245285 | 1011 | exit_notify(tsk); |
1da177e4 LT |
1012 | #ifdef CONFIG_NUMA |
1013 | mpol_free(tsk->mempolicy); | |
1014 | tsk->mempolicy = NULL; | |
1015 | #endif | |
42b2dd0a | 1016 | #ifdef CONFIG_FUTEX |
c87e2837 IM |
1017 | /* |
1018 | * This must happen late, after the PID is not | |
1019 | * hashed anymore: | |
1020 | */ | |
1021 | if (unlikely(!list_empty(&tsk->pi_state_list))) | |
1022 | exit_pi_state_list(tsk); | |
1023 | if (unlikely(current->pi_state_cache)) | |
1024 | kfree(current->pi_state_cache); | |
42b2dd0a | 1025 | #endif |
de5097c2 | 1026 | /* |
9a11b49a | 1027 | * Make sure we are holding no locks: |
de5097c2 | 1028 | */ |
9a11b49a | 1029 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1030 | /* |
1031 | * We can do this unlocked here. The futex code uses this flag | |
1032 | * just to verify whether the pi state cleanup has been done | |
1033 | * or not. In the worst case it loops once more. | |
1034 | */ | |
1035 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1036 | |
afc847b7 AV |
1037 | if (tsk->io_context) |
1038 | exit_io_context(); | |
1039 | ||
b92ce558 JA |
1040 | if (tsk->splice_pipe) |
1041 | __free_pipe_info(tsk->splice_pipe); | |
1042 | ||
7407251a | 1043 | preempt_disable(); |
55a101f8 | 1044 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1045 | tsk->state = TASK_DEAD; |
7407251a | 1046 | |
1da177e4 LT |
1047 | schedule(); |
1048 | BUG(); | |
1049 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1050 | for (;;) |
1051 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1052 | } |
1053 | ||
012914da RA |
1054 | EXPORT_SYMBOL_GPL(do_exit); |
1055 | ||
1da177e4 LT |
1056 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1057 | { | |
1058 | if (comp) | |
1059 | complete(comp); | |
55a101f8 | 1060 | |
1da177e4 LT |
1061 | do_exit(code); |
1062 | } | |
1063 | ||
1064 | EXPORT_SYMBOL(complete_and_exit); | |
1065 | ||
1066 | asmlinkage long sys_exit(int error_code) | |
1067 | { | |
1068 | do_exit((error_code&0xff)<<8); | |
1069 | } | |
1070 | ||
1da177e4 LT |
1071 | /* |
1072 | * Take down every thread in the group. This is called by fatal signals | |
1073 | * as well as by sys_exit_group (below). | |
1074 | */ | |
1075 | NORET_TYPE void | |
1076 | do_group_exit(int exit_code) | |
1077 | { | |
1078 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ | |
1079 | ||
1080 | if (current->signal->flags & SIGNAL_GROUP_EXIT) | |
1081 | exit_code = current->signal->group_exit_code; | |
1082 | else if (!thread_group_empty(current)) { | |
1083 | struct signal_struct *const sig = current->signal; | |
1084 | struct sighand_struct *const sighand = current->sighand; | |
1da177e4 | 1085 | spin_lock_irq(&sighand->siglock); |
ed5d2cac | 1086 | if (signal_group_exit(sig)) |
1da177e4 LT |
1087 | /* Another thread got here before we took the lock. */ |
1088 | exit_code = sig->group_exit_code; | |
1089 | else { | |
1da177e4 | 1090 | sig->group_exit_code = exit_code; |
ed5d2cac | 1091 | sig->flags = SIGNAL_GROUP_EXIT; |
1da177e4 LT |
1092 | zap_other_threads(current); |
1093 | } | |
1094 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1095 | } |
1096 | ||
1097 | do_exit(exit_code); | |
1098 | /* NOTREACHED */ | |
1099 | } | |
1100 | ||
1101 | /* | |
1102 | * this kills every thread in the thread group. Note that any externally | |
1103 | * wait4()-ing process will get the correct exit code - even if this | |
1104 | * thread is not the thread group leader. | |
1105 | */ | |
1106 | asmlinkage void sys_exit_group(int error_code) | |
1107 | { | |
1108 | do_group_exit((error_code & 0xff) << 8); | |
1109 | } | |
1110 | ||
36c8b586 | 1111 | static int eligible_child(pid_t pid, int options, struct task_struct *p) |
1da177e4 | 1112 | { |
73243284 | 1113 | int err; |
b488893a | 1114 | struct pid_namespace *ns; |
73243284 | 1115 | |
b488893a | 1116 | ns = current->nsproxy->pid_ns; |
1da177e4 | 1117 | if (pid > 0) { |
b488893a | 1118 | if (task_pid_nr_ns(p, ns) != pid) |
1da177e4 LT |
1119 | return 0; |
1120 | } else if (!pid) { | |
b488893a | 1121 | if (task_pgrp_nr_ns(p, ns) != task_pgrp_vnr(current)) |
1da177e4 LT |
1122 | return 0; |
1123 | } else if (pid != -1) { | |
b488893a | 1124 | if (task_pgrp_nr_ns(p, ns) != -pid) |
1da177e4 LT |
1125 | return 0; |
1126 | } | |
1127 | ||
1128 | /* | |
1129 | * Do not consider detached threads that are | |
1130 | * not ptraced: | |
1131 | */ | |
1132 | if (p->exit_signal == -1 && !p->ptrace) | |
1133 | return 0; | |
1134 | ||
1135 | /* Wait for all children (clone and not) if __WALL is set; | |
1136 | * otherwise, wait for clone children *only* if __WCLONE is | |
1137 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1138 | * A "clone" child here is one that reports to its parent | |
1139 | * using a signal other than SIGCHLD.) */ | |
1140 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1141 | && !(options & __WALL)) | |
1142 | return 0; | |
1143 | /* | |
1144 | * Do not consider thread group leaders that are | |
1145 | * in a non-empty thread group: | |
1146 | */ | |
3b6362b8 | 1147 | if (delay_group_leader(p)) |
1da177e4 LT |
1148 | return 2; |
1149 | ||
73243284 RM |
1150 | err = security_task_wait(p); |
1151 | if (err) | |
1152 | return err; | |
1da177e4 LT |
1153 | |
1154 | return 1; | |
1155 | } | |
1156 | ||
36c8b586 | 1157 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1158 | int why, int status, |
1159 | struct siginfo __user *infop, | |
1160 | struct rusage __user *rusagep) | |
1161 | { | |
1162 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1163 | |
1da177e4 LT |
1164 | put_task_struct(p); |
1165 | if (!retval) | |
1166 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1167 | if (!retval) | |
1168 | retval = put_user(0, &infop->si_errno); | |
1169 | if (!retval) | |
1170 | retval = put_user((short)why, &infop->si_code); | |
1171 | if (!retval) | |
1172 | retval = put_user(pid, &infop->si_pid); | |
1173 | if (!retval) | |
1174 | retval = put_user(uid, &infop->si_uid); | |
1175 | if (!retval) | |
1176 | retval = put_user(status, &infop->si_status); | |
1177 | if (!retval) | |
1178 | retval = pid; | |
1179 | return retval; | |
1180 | } | |
1181 | ||
1182 | /* | |
1183 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1184 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1185 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1186 | * released the lock and the system call should return. | |
1187 | */ | |
36c8b586 | 1188 | static int wait_task_zombie(struct task_struct *p, int noreap, |
1da177e4 LT |
1189 | struct siginfo __user *infop, |
1190 | int __user *stat_addr, struct rusage __user *ru) | |
1191 | { | |
1192 | unsigned long state; | |
2f4e6e2a | 1193 | int retval, status, traced; |
b488893a PE |
1194 | struct pid_namespace *ns; |
1195 | ||
1196 | ns = current->nsproxy->pid_ns; | |
1da177e4 LT |
1197 | |
1198 | if (unlikely(noreap)) { | |
b488893a | 1199 | pid_t pid = task_pid_nr_ns(p, ns); |
1da177e4 LT |
1200 | uid_t uid = p->uid; |
1201 | int exit_code = p->exit_code; | |
1202 | int why, status; | |
1203 | ||
1204 | if (unlikely(p->exit_state != EXIT_ZOMBIE)) | |
1205 | return 0; | |
1206 | if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) | |
1207 | return 0; | |
1208 | get_task_struct(p); | |
1209 | read_unlock(&tasklist_lock); | |
1210 | if ((exit_code & 0x7f) == 0) { | |
1211 | why = CLD_EXITED; | |
1212 | status = exit_code >> 8; | |
1213 | } else { | |
1214 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1215 | status = exit_code & 0x7f; | |
1216 | } | |
1217 | return wait_noreap_copyout(p, pid, uid, why, | |
1218 | status, infop, ru); | |
1219 | } | |
1220 | ||
1221 | /* | |
1222 | * Try to move the task's state to DEAD | |
1223 | * only one thread is allowed to do this: | |
1224 | */ | |
1225 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1226 | if (state != EXIT_ZOMBIE) { | |
1227 | BUG_ON(state != EXIT_DEAD); | |
1228 | return 0; | |
1229 | } | |
1da177e4 | 1230 | |
2f4e6e2a ON |
1231 | /* traced means p->ptrace, but not vice versa */ |
1232 | traced = (p->real_parent != p->parent); | |
1233 | ||
1234 | if (likely(!traced)) { | |
3795e161 JJ |
1235 | struct signal_struct *psig; |
1236 | struct signal_struct *sig; | |
1237 | ||
1da177e4 LT |
1238 | /* |
1239 | * The resource counters for the group leader are in its | |
1240 | * own task_struct. Those for dead threads in the group | |
1241 | * are in its signal_struct, as are those for the child | |
1242 | * processes it has previously reaped. All these | |
1243 | * accumulate in the parent's signal_struct c* fields. | |
1244 | * | |
1245 | * We don't bother to take a lock here to protect these | |
1246 | * p->signal fields, because they are only touched by | |
1247 | * __exit_signal, which runs with tasklist_lock | |
1248 | * write-locked anyway, and so is excluded here. We do | |
1249 | * need to protect the access to p->parent->signal fields, | |
1250 | * as other threads in the parent group can be right | |
1251 | * here reaping other children at the same time. | |
1252 | */ | |
1253 | spin_lock_irq(&p->parent->sighand->siglock); | |
3795e161 JJ |
1254 | psig = p->parent->signal; |
1255 | sig = p->signal; | |
1256 | psig->cutime = | |
1257 | cputime_add(psig->cutime, | |
1da177e4 | 1258 | cputime_add(p->utime, |
3795e161 JJ |
1259 | cputime_add(sig->utime, |
1260 | sig->cutime))); | |
1261 | psig->cstime = | |
1262 | cputime_add(psig->cstime, | |
1da177e4 | 1263 | cputime_add(p->stime, |
3795e161 JJ |
1264 | cputime_add(sig->stime, |
1265 | sig->cstime))); | |
9ac52315 LV |
1266 | psig->cgtime = |
1267 | cputime_add(psig->cgtime, | |
1268 | cputime_add(p->gtime, | |
1269 | cputime_add(sig->gtime, | |
1270 | sig->cgtime))); | |
3795e161 JJ |
1271 | psig->cmin_flt += |
1272 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1273 | psig->cmaj_flt += | |
1274 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1275 | psig->cnvcsw += | |
1276 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1277 | psig->cnivcsw += | |
1278 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1279 | psig->cinblock += |
1280 | task_io_get_inblock(p) + | |
1281 | sig->inblock + sig->cinblock; | |
1282 | psig->coublock += | |
1283 | task_io_get_oublock(p) + | |
1284 | sig->oublock + sig->coublock; | |
1da177e4 LT |
1285 | spin_unlock_irq(&p->parent->sighand->siglock); |
1286 | } | |
1287 | ||
1288 | /* | |
1289 | * Now we are sure this task is interesting, and no other | |
1290 | * thread can reap it because we set its state to EXIT_DEAD. | |
1291 | */ | |
1292 | read_unlock(&tasklist_lock); | |
1293 | ||
1294 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1295 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1296 | ? p->signal->group_exit_code : p->exit_code; | |
1297 | if (!retval && stat_addr) | |
1298 | retval = put_user(status, stat_addr); | |
1299 | if (!retval && infop) | |
1300 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1301 | if (!retval && infop) | |
1302 | retval = put_user(0, &infop->si_errno); | |
1303 | if (!retval && infop) { | |
1304 | int why; | |
1305 | ||
1306 | if ((status & 0x7f) == 0) { | |
1307 | why = CLD_EXITED; | |
1308 | status >>= 8; | |
1309 | } else { | |
1310 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1311 | status &= 0x7f; | |
1312 | } | |
1313 | retval = put_user((short)why, &infop->si_code); | |
1314 | if (!retval) | |
1315 | retval = put_user(status, &infop->si_status); | |
1316 | } | |
1317 | if (!retval && infop) | |
b488893a | 1318 | retval = put_user(task_pid_nr_ns(p, ns), &infop->si_pid); |
1da177e4 LT |
1319 | if (!retval && infop) |
1320 | retval = put_user(p->uid, &infop->si_uid); | |
2f4e6e2a | 1321 | if (!retval) |
b488893a | 1322 | retval = task_pid_nr_ns(p, ns); |
2f4e6e2a ON |
1323 | |
1324 | if (traced) { | |
1da177e4 | 1325 | write_lock_irq(&tasklist_lock); |
2f4e6e2a ON |
1326 | /* We dropped tasklist, ptracer could die and untrace */ |
1327 | ptrace_unlink(p); | |
1328 | /* | |
1329 | * If this is not a detached task, notify the parent. | |
1330 | * If it's still not detached after that, don't release | |
1331 | * it now. | |
1332 | */ | |
1333 | if (p->exit_signal != -1) { | |
1334 | do_notify_parent(p, p->exit_signal); | |
1da177e4 | 1335 | if (p->exit_signal != -1) { |
2f4e6e2a ON |
1336 | p->exit_state = EXIT_ZOMBIE; |
1337 | p = NULL; | |
1da177e4 LT |
1338 | } |
1339 | } | |
1340 | write_unlock_irq(&tasklist_lock); | |
1341 | } | |
1342 | if (p != NULL) | |
1343 | release_task(p); | |
2f4e6e2a | 1344 | |
1da177e4 LT |
1345 | return retval; |
1346 | } | |
1347 | ||
1348 | /* | |
1349 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1350 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1351 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1352 | * released the lock and the system call should return. | |
1353 | */ | |
36c8b586 IM |
1354 | static int wait_task_stopped(struct task_struct *p, int delayed_group_leader, |
1355 | int noreap, struct siginfo __user *infop, | |
1da177e4 LT |
1356 | int __user *stat_addr, struct rusage __user *ru) |
1357 | { | |
1358 | int retval, exit_code; | |
c8950783 | 1359 | pid_t pid; |
1da177e4 LT |
1360 | |
1361 | if (!p->exit_code) | |
1362 | return 0; | |
1363 | if (delayed_group_leader && !(p->ptrace & PT_PTRACED) && | |
715015e8 | 1364 | p->signal->group_stop_count > 0) |
1da177e4 LT |
1365 | /* |
1366 | * A group stop is in progress and this is the group leader. | |
1367 | * We won't report until all threads have stopped. | |
1368 | */ | |
1369 | return 0; | |
1370 | ||
1371 | /* | |
1372 | * Now we are pretty sure this task is interesting. | |
1373 | * Make sure it doesn't get reaped out from under us while we | |
1374 | * give up the lock and then examine it below. We don't want to | |
1375 | * keep holding onto the tasklist_lock while we call getrusage and | |
1376 | * possibly take page faults for user memory. | |
1377 | */ | |
c8950783 | 1378 | pid = task_pid_nr_ns(p, current->nsproxy->pid_ns); |
1da177e4 LT |
1379 | get_task_struct(p); |
1380 | read_unlock(&tasklist_lock); | |
1381 | ||
1382 | if (unlikely(noreap)) { | |
1da177e4 LT |
1383 | uid_t uid = p->uid; |
1384 | int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; | |
1385 | ||
1386 | exit_code = p->exit_code; | |
a3474224 | 1387 | if (unlikely(!exit_code) || unlikely(p->exit_state)) |
1da177e4 LT |
1388 | goto bail_ref; |
1389 | return wait_noreap_copyout(p, pid, uid, | |
e6ceb32a | 1390 | why, exit_code, |
1da177e4 LT |
1391 | infop, ru); |
1392 | } | |
1393 | ||
1394 | write_lock_irq(&tasklist_lock); | |
1395 | ||
1396 | /* | |
1397 | * This uses xchg to be atomic with the thread resuming and setting | |
1398 | * it. It must also be done with the write lock held to prevent a | |
1399 | * race with the EXIT_ZOMBIE case. | |
1400 | */ | |
1401 | exit_code = xchg(&p->exit_code, 0); | |
1402 | if (unlikely(p->exit_state)) { | |
1403 | /* | |
1404 | * The task resumed and then died. Let the next iteration | |
1405 | * catch it in EXIT_ZOMBIE. Note that exit_code might | |
1406 | * already be zero here if it resumed and did _exit(0). | |
1407 | * The task itself is dead and won't touch exit_code again; | |
1408 | * other processors in this function are locked out. | |
1409 | */ | |
1410 | p->exit_code = exit_code; | |
1411 | exit_code = 0; | |
1412 | } | |
1413 | if (unlikely(exit_code == 0)) { | |
1414 | /* | |
1415 | * Another thread in this function got to it first, or it | |
1416 | * resumed, or it resumed and then died. | |
1417 | */ | |
1418 | write_unlock_irq(&tasklist_lock); | |
1419 | bail_ref: | |
1420 | put_task_struct(p); | |
1421 | /* | |
1422 | * We are returning to the wait loop without having successfully | |
1423 | * removed the process and having released the lock. We cannot | |
1424 | * continue, since the "p" task pointer is potentially stale. | |
1425 | * | |
1426 | * Return -EAGAIN, and do_wait() will restart the loop from the | |
1427 | * beginning. Do _not_ re-acquire the lock. | |
1428 | */ | |
1429 | return -EAGAIN; | |
1430 | } | |
1431 | ||
1432 | /* move to end of parent's list to avoid starvation */ | |
1433 | remove_parent(p); | |
8fafabd8 | 1434 | add_parent(p); |
1da177e4 LT |
1435 | |
1436 | write_unlock_irq(&tasklist_lock); | |
1437 | ||
1438 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1439 | if (!retval && stat_addr) | |
1440 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1441 | if (!retval && infop) | |
1442 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1443 | if (!retval && infop) | |
1444 | retval = put_user(0, &infop->si_errno); | |
1445 | if (!retval && infop) | |
1446 | retval = put_user((short)((p->ptrace & PT_PTRACED) | |
1447 | ? CLD_TRAPPED : CLD_STOPPED), | |
1448 | &infop->si_code); | |
1449 | if (!retval && infop) | |
1450 | retval = put_user(exit_code, &infop->si_status); | |
1451 | if (!retval && infop) | |
c8950783 | 1452 | retval = put_user(pid, &infop->si_pid); |
1da177e4 LT |
1453 | if (!retval && infop) |
1454 | retval = put_user(p->uid, &infop->si_uid); | |
1455 | if (!retval) | |
c8950783 | 1456 | retval = pid; |
1da177e4 LT |
1457 | put_task_struct(p); |
1458 | ||
1459 | BUG_ON(!retval); | |
1460 | return retval; | |
1461 | } | |
1462 | ||
1463 | /* | |
1464 | * Handle do_wait work for one task in a live, non-stopped state. | |
1465 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1466 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1467 | * released the lock and the system call should return. | |
1468 | */ | |
36c8b586 | 1469 | static int wait_task_continued(struct task_struct *p, int noreap, |
1da177e4 LT |
1470 | struct siginfo __user *infop, |
1471 | int __user *stat_addr, struct rusage __user *ru) | |
1472 | { | |
1473 | int retval; | |
1474 | pid_t pid; | |
1475 | uid_t uid; | |
b488893a | 1476 | struct pid_namespace *ns; |
1da177e4 | 1477 | |
1da177e4 LT |
1478 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
1479 | return 0; | |
1480 | ||
1481 | spin_lock_irq(&p->sighand->siglock); | |
1482 | /* Re-check with the lock held. */ | |
1483 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1484 | spin_unlock_irq(&p->sighand->siglock); | |
1485 | return 0; | |
1486 | } | |
1487 | if (!noreap) | |
1488 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; | |
1489 | spin_unlock_irq(&p->sighand->siglock); | |
1490 | ||
b488893a PE |
1491 | ns = current->nsproxy->pid_ns; |
1492 | pid = task_pid_nr_ns(p, ns); | |
1da177e4 LT |
1493 | uid = p->uid; |
1494 | get_task_struct(p); | |
1495 | read_unlock(&tasklist_lock); | |
1496 | ||
1497 | if (!infop) { | |
1498 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1499 | put_task_struct(p); | |
1500 | if (!retval && stat_addr) | |
1501 | retval = put_user(0xffff, stat_addr); | |
1502 | if (!retval) | |
b488893a | 1503 | retval = task_pid_nr_ns(p, ns); |
1da177e4 LT |
1504 | } else { |
1505 | retval = wait_noreap_copyout(p, pid, uid, | |
1506 | CLD_CONTINUED, SIGCONT, | |
1507 | infop, ru); | |
1508 | BUG_ON(retval == 0); | |
1509 | } | |
1510 | ||
1511 | return retval; | |
1512 | } | |
1513 | ||
1514 | ||
1515 | static inline int my_ptrace_child(struct task_struct *p) | |
1516 | { | |
1517 | if (!(p->ptrace & PT_PTRACED)) | |
1518 | return 0; | |
1519 | if (!(p->ptrace & PT_ATTACHED)) | |
1520 | return 1; | |
1521 | /* | |
1522 | * This child was PTRACE_ATTACH'd. We should be seeing it only if | |
1523 | * we are the attacher. If we are the real parent, this is a race | |
1524 | * inside ptrace_attach. It is waiting for the tasklist_lock, | |
1525 | * which we have to switch the parent links, but has already set | |
1526 | * the flags in p->ptrace. | |
1527 | */ | |
1528 | return (p->parent != p->real_parent); | |
1529 | } | |
1530 | ||
1531 | static long do_wait(pid_t pid, int options, struct siginfo __user *infop, | |
1532 | int __user *stat_addr, struct rusage __user *ru) | |
1533 | { | |
1534 | DECLARE_WAITQUEUE(wait, current); | |
1535 | struct task_struct *tsk; | |
1536 | int flag, retval; | |
73243284 | 1537 | int allowed, denied; |
1da177e4 LT |
1538 | |
1539 | add_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1540 | repeat: | |
1541 | /* | |
1542 | * We will set this flag if we see any child that might later | |
1543 | * match our criteria, even if we are not able to reap it yet. | |
1544 | */ | |
1545 | flag = 0; | |
73243284 | 1546 | allowed = denied = 0; |
1da177e4 LT |
1547 | current->state = TASK_INTERRUPTIBLE; |
1548 | read_lock(&tasklist_lock); | |
1549 | tsk = current; | |
1550 | do { | |
1551 | struct task_struct *p; | |
1da177e4 LT |
1552 | int ret; |
1553 | ||
03ff1797 | 1554 | list_for_each_entry(p, &tsk->children, sibling) { |
1da177e4 LT |
1555 | ret = eligible_child(pid, options, p); |
1556 | if (!ret) | |
1557 | continue; | |
1558 | ||
73243284 RM |
1559 | if (unlikely(ret < 0)) { |
1560 | denied = ret; | |
1561 | continue; | |
1562 | } | |
1563 | allowed = 1; | |
1564 | ||
338077e5 | 1565 | if (task_is_stopped_or_traced(p)) { |
1da177e4 LT |
1566 | /* |
1567 | * It's stopped now, so it might later | |
1568 | * continue, exit, or stop again. | |
338077e5 MW |
1569 | * |
1570 | * When we hit the race with PTRACE_ATTACH, we | |
1571 | * will not report this child. But the race | |
1572 | * means it has not yet been moved to our | |
1573 | * ptrace_children list, so we need to set the | |
1574 | * flag here to avoid a spurious ECHILD when | |
1575 | * the race happens with the only child. | |
1da177e4 LT |
1576 | */ |
1577 | flag = 1; | |
338077e5 MW |
1578 | |
1579 | if (!my_ptrace_child(p)) { | |
1580 | if (task_is_traced(p)) | |
1581 | continue; | |
1582 | if (!(options & WUNTRACED)) | |
1583 | continue; | |
1584 | } | |
1585 | ||
1da177e4 | 1586 | retval = wait_task_stopped(p, ret == 2, |
338077e5 MW |
1587 | (options & WNOWAIT), infop, |
1588 | stat_addr, ru); | |
1da177e4 LT |
1589 | if (retval == -EAGAIN) |
1590 | goto repeat; | |
1591 | if (retval != 0) /* He released the lock. */ | |
1592 | goto end; | |
338077e5 MW |
1593 | } else if (p->exit_state == EXIT_ZOMBIE) { |
1594 | /* | |
1595 | * Eligible but we cannot release it yet: | |
1596 | */ | |
1597 | if (ret == 2) | |
1598 | goto check_continued; | |
1599 | if (!likely(options & WEXITED)) | |
1da177e4 | 1600 | continue; |
338077e5 MW |
1601 | retval = wait_task_zombie(p, |
1602 | (options & WNOWAIT), infop, | |
1603 | stat_addr, ru); | |
1604 | /* He released the lock. */ | |
1605 | if (retval != 0) | |
1606 | goto end; | |
0a76fe8e | 1607 | } else if (p->exit_state != EXIT_DEAD) { |
1da177e4 LT |
1608 | check_continued: |
1609 | /* | |
1610 | * It's running now, so it might later | |
1611 | * exit, stop, or stop and then continue. | |
1612 | */ | |
1613 | flag = 1; | |
1614 | if (!unlikely(options & WCONTINUED)) | |
1615 | continue; | |
338077e5 MW |
1616 | retval = wait_task_continued(p, |
1617 | (options & WNOWAIT), infop, | |
1618 | stat_addr, ru); | |
1da177e4 LT |
1619 | if (retval != 0) /* He released the lock. */ |
1620 | goto end; | |
1da177e4 LT |
1621 | } |
1622 | } | |
1623 | if (!flag) { | |
03ff1797 MK |
1624 | list_for_each_entry(p, &tsk->ptrace_children, |
1625 | ptrace_list) { | |
1da177e4 LT |
1626 | if (!eligible_child(pid, options, p)) |
1627 | continue; | |
1628 | flag = 1; | |
1629 | break; | |
1630 | } | |
1631 | } | |
1632 | if (options & __WNOTHREAD) | |
1633 | break; | |
1634 | tsk = next_thread(tsk); | |
125e1874 | 1635 | BUG_ON(tsk->signal != current->signal); |
1da177e4 LT |
1636 | } while (tsk != current); |
1637 | ||
1638 | read_unlock(&tasklist_lock); | |
1639 | if (flag) { | |
1640 | retval = 0; | |
1641 | if (options & WNOHANG) | |
1642 | goto end; | |
1643 | retval = -ERESTARTSYS; | |
1644 | if (signal_pending(current)) | |
1645 | goto end; | |
1646 | schedule(); | |
1647 | goto repeat; | |
1648 | } | |
1649 | retval = -ECHILD; | |
73243284 RM |
1650 | if (unlikely(denied) && !allowed) |
1651 | retval = denied; | |
1da177e4 LT |
1652 | end: |
1653 | current->state = TASK_RUNNING; | |
1654 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1655 | if (infop) { | |
1656 | if (retval > 0) | |
1657 | retval = 0; | |
1658 | else { | |
1659 | /* | |
1660 | * For a WNOHANG return, clear out all the fields | |
1661 | * we would set so the user can easily tell the | |
1662 | * difference. | |
1663 | */ | |
1664 | if (!retval) | |
1665 | retval = put_user(0, &infop->si_signo); | |
1666 | if (!retval) | |
1667 | retval = put_user(0, &infop->si_errno); | |
1668 | if (!retval) | |
1669 | retval = put_user(0, &infop->si_code); | |
1670 | if (!retval) | |
1671 | retval = put_user(0, &infop->si_pid); | |
1672 | if (!retval) | |
1673 | retval = put_user(0, &infop->si_uid); | |
1674 | if (!retval) | |
1675 | retval = put_user(0, &infop->si_status); | |
1676 | } | |
1677 | } | |
1678 | return retval; | |
1679 | } | |
1680 | ||
1681 | asmlinkage long sys_waitid(int which, pid_t pid, | |
1682 | struct siginfo __user *infop, int options, | |
1683 | struct rusage __user *ru) | |
1684 | { | |
1685 | long ret; | |
1686 | ||
1687 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1688 | return -EINVAL; | |
1689 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1690 | return -EINVAL; | |
1691 | ||
1692 | switch (which) { | |
1693 | case P_ALL: | |
1694 | pid = -1; | |
1695 | break; | |
1696 | case P_PID: | |
1697 | if (pid <= 0) | |
1698 | return -EINVAL; | |
1699 | break; | |
1700 | case P_PGID: | |
1701 | if (pid <= 0) | |
1702 | return -EINVAL; | |
1703 | pid = -pid; | |
1704 | break; | |
1705 | default: | |
1706 | return -EINVAL; | |
1707 | } | |
1708 | ||
1709 | ret = do_wait(pid, options, infop, NULL, ru); | |
1710 | ||
1711 | /* avoid REGPARM breakage on x86: */ | |
1712 | prevent_tail_call(ret); | |
1713 | return ret; | |
1714 | } | |
1715 | ||
1716 | asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr, | |
1717 | int options, struct rusage __user *ru) | |
1718 | { | |
1719 | long ret; | |
1720 | ||
1721 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1722 | __WNOTHREAD|__WCLONE|__WALL)) | |
1723 | return -EINVAL; | |
1724 | ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru); | |
1725 | ||
1726 | /* avoid REGPARM breakage on x86: */ | |
1727 | prevent_tail_call(ret); | |
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 | */ | |
1737 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) | |
1738 | { | |
1739 | return sys_wait4(pid, stat_addr, options, NULL); | |
1740 | } | |
1741 | ||
1742 | #endif |