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> | |
fba2afaa | 27 | #include <linux/signalfd.h> |
1da177e4 LT |
28 | #include <linux/mount.h> |
29 | #include <linux/proc_fs.h> | |
49d769d5 | 30 | #include <linux/kthread.h> |
1da177e4 | 31 | #include <linux/mempolicy.h> |
c757249a | 32 | #include <linux/taskstats_kern.h> |
ca74e92b | 33 | #include <linux/delayacct.h> |
83144186 | 34 | #include <linux/freezer.h> |
1da177e4 LT |
35 | #include <linux/cpuset.h> |
36 | #include <linux/syscalls.h> | |
7ed20e1a | 37 | #include <linux/signal.h> |
6a14c5c9 | 38 | #include <linux/posix-timers.h> |
9f46080c | 39 | #include <linux/cn_proc.h> |
de5097c2 | 40 | #include <linux/mutex.h> |
0771dfef | 41 | #include <linux/futex.h> |
34f192c6 | 42 | #include <linux/compat.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> |
0c1eecfb | 48 | #include <linux/freezer.h> |
1da177e4 LT |
49 | |
50 | #include <asm/uaccess.h> | |
51 | #include <asm/unistd.h> | |
52 | #include <asm/pgtable.h> | |
53 | #include <asm/mmu_context.h> | |
54 | ||
55 | extern void sem_exit (void); | |
1da177e4 | 56 | |
408b664a AB |
57 | static void exit_mm(struct task_struct * tsk); |
58 | ||
1da177e4 LT |
59 | static void __unhash_process(struct task_struct *p) |
60 | { | |
61 | nr_threads--; | |
62 | detach_pid(p, PIDTYPE_PID); | |
1da177e4 LT |
63 | if (thread_group_leader(p)) { |
64 | detach_pid(p, PIDTYPE_PGID); | |
65 | detach_pid(p, PIDTYPE_SID); | |
c97d9893 | 66 | |
5e85d4ab | 67 | list_del_rcu(&p->tasks); |
73b9ebfe | 68 | __get_cpu_var(process_counts)--; |
1da177e4 | 69 | } |
47e65328 | 70 | list_del_rcu(&p->thread_group); |
c97d9893 | 71 | remove_parent(p); |
1da177e4 LT |
72 | } |
73 | ||
6a14c5c9 ON |
74 | /* |
75 | * This function expects the tasklist_lock write-locked. | |
76 | */ | |
77 | static void __exit_signal(struct task_struct *tsk) | |
78 | { | |
79 | struct signal_struct *sig = tsk->signal; | |
80 | struct sighand_struct *sighand; | |
81 | ||
82 | BUG_ON(!sig); | |
83 | BUG_ON(!atomic_read(&sig->count)); | |
84 | ||
85 | rcu_read_lock(); | |
86 | sighand = rcu_dereference(tsk->sighand); | |
87 | spin_lock(&sighand->siglock); | |
88 | ||
fba2afaa DL |
89 | /* |
90 | * Notify that this sighand has been detached. This must | |
91 | * be called with the tsk->sighand lock held. Also, this | |
92 | * access tsk->sighand internally, so it must be called | |
93 | * before tsk->sighand is reset. | |
94 | */ | |
95 | signalfd_detach_locked(tsk); | |
96 | ||
6a14c5c9 ON |
97 | posix_cpu_timers_exit(tsk); |
98 | if (atomic_dec_and_test(&sig->count)) | |
99 | posix_cpu_timers_exit_group(tsk); | |
100 | else { | |
101 | /* | |
102 | * If there is any task waiting for the group exit | |
103 | * then notify it: | |
104 | */ | |
105 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) { | |
106 | wake_up_process(sig->group_exit_task); | |
107 | sig->group_exit_task = NULL; | |
108 | } | |
109 | if (tsk == sig->curr_target) | |
110 | sig->curr_target = next_thread(tsk); | |
111 | /* | |
112 | * Accumulate here the counters for all threads but the | |
113 | * group leader as they die, so they can be added into | |
114 | * the process-wide totals when those are taken. | |
115 | * The group leader stays around as a zombie as long | |
116 | * as there are other threads. When it gets reaped, | |
117 | * the exit.c code will add its counts into these totals. | |
118 | * We won't ever get here for the group leader, since it | |
119 | * will have been the last reference on the signal_struct. | |
120 | */ | |
121 | sig->utime = cputime_add(sig->utime, tsk->utime); | |
122 | sig->stime = cputime_add(sig->stime, tsk->stime); | |
123 | sig->min_flt += tsk->min_flt; | |
124 | sig->maj_flt += tsk->maj_flt; | |
125 | sig->nvcsw += tsk->nvcsw; | |
126 | sig->nivcsw += tsk->nivcsw; | |
6eaeeaba ED |
127 | sig->inblock += task_io_get_inblock(tsk); |
128 | sig->oublock += task_io_get_oublock(tsk); | |
172ba844 | 129 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
6a14c5c9 ON |
130 | sig = NULL; /* Marker for below. */ |
131 | } | |
132 | ||
5876700c ON |
133 | __unhash_process(tsk); |
134 | ||
6a14c5c9 | 135 | tsk->signal = NULL; |
a7e5328a | 136 | tsk->sighand = NULL; |
6a14c5c9 ON |
137 | spin_unlock(&sighand->siglock); |
138 | rcu_read_unlock(); | |
139 | ||
a7e5328a | 140 | __cleanup_sighand(sighand); |
6a14c5c9 ON |
141 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
142 | flush_sigqueue(&tsk->pending); | |
143 | if (sig) { | |
144 | flush_sigqueue(&sig->shared_pending); | |
093a8e8a | 145 | taskstats_tgid_free(sig); |
6a14c5c9 ON |
146 | __cleanup_signal(sig); |
147 | } | |
148 | } | |
149 | ||
8c7904a0 EB |
150 | static void delayed_put_task_struct(struct rcu_head *rhp) |
151 | { | |
152 | put_task_struct(container_of(rhp, struct task_struct, rcu)); | |
153 | } | |
154 | ||
1da177e4 LT |
155 | void release_task(struct task_struct * p) |
156 | { | |
36c8b586 | 157 | struct task_struct *leader; |
1da177e4 | 158 | int zap_leader; |
1f09f974 | 159 | repeat: |
1da177e4 | 160 | atomic_dec(&p->user->processes); |
1da177e4 | 161 | write_lock_irq(&tasklist_lock); |
1f09f974 | 162 | ptrace_unlink(p); |
1da177e4 LT |
163 | BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); |
164 | __exit_signal(p); | |
35f5cad8 | 165 | |
1da177e4 LT |
166 | /* |
167 | * If we are the last non-leader member of the thread | |
168 | * group, and the leader is zombie, then notify the | |
169 | * group leader's parent process. (if it wants notification.) | |
170 | */ | |
171 | zap_leader = 0; | |
172 | leader = p->group_leader; | |
173 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { | |
174 | BUG_ON(leader->exit_signal == -1); | |
175 | do_notify_parent(leader, leader->exit_signal); | |
176 | /* | |
177 | * If we were the last child thread and the leader has | |
178 | * exited already, and the leader's parent ignores SIGCHLD, | |
179 | * then we are the one who should release the leader. | |
180 | * | |
181 | * do_notify_parent() will have marked it self-reaping in | |
182 | * that case. | |
183 | */ | |
184 | zap_leader = (leader->exit_signal == -1); | |
185 | } | |
186 | ||
1da177e4 | 187 | write_unlock_irq(&tasklist_lock); |
48e6484d | 188 | proc_flush_task(p); |
1da177e4 | 189 | release_thread(p); |
8c7904a0 | 190 | call_rcu(&p->rcu, delayed_put_task_struct); |
1da177e4 LT |
191 | |
192 | p = leader; | |
193 | if (unlikely(zap_leader)) | |
194 | goto repeat; | |
195 | } | |
196 | ||
1da177e4 LT |
197 | /* |
198 | * This checks not only the pgrp, but falls back on the pid if no | |
199 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
200 | * without this... | |
04a2e6a5 EB |
201 | * |
202 | * The caller must hold rcu lock or the tasklist lock. | |
1da177e4 | 203 | */ |
04a2e6a5 | 204 | struct pid *session_of_pgrp(struct pid *pgrp) |
1da177e4 LT |
205 | { |
206 | struct task_struct *p; | |
04a2e6a5 | 207 | struct pid *sid = NULL; |
62dfb554 | 208 | |
04a2e6a5 | 209 | p = pid_task(pgrp, PIDTYPE_PGID); |
62dfb554 | 210 | if (p == NULL) |
04a2e6a5 | 211 | p = pid_task(pgrp, PIDTYPE_PID); |
62dfb554 | 212 | if (p != NULL) |
04a2e6a5 | 213 | sid = task_session(p); |
62dfb554 | 214 | |
1da177e4 LT |
215 | return sid; |
216 | } | |
217 | ||
218 | /* | |
219 | * Determine if a process group is "orphaned", according to the POSIX | |
220 | * definition in 2.2.2.52. Orphaned process groups are not to be affected | |
221 | * by terminal-generated stop signals. Newly orphaned process groups are | |
222 | * to receive a SIGHUP and a SIGCONT. | |
223 | * | |
224 | * "I ask you, have you ever known what it is to be an orphan?" | |
225 | */ | |
0475ac08 | 226 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) |
1da177e4 LT |
227 | { |
228 | struct task_struct *p; | |
229 | int ret = 1; | |
230 | ||
0475ac08 | 231 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
232 | if (p == ignored_task |
233 | || p->exit_state | |
f400e198 | 234 | || is_init(p->real_parent)) |
1da177e4 | 235 | continue; |
0475ac08 EB |
236 | if (task_pgrp(p->real_parent) != pgrp && |
237 | task_session(p->real_parent) == task_session(p)) { | |
1da177e4 LT |
238 | ret = 0; |
239 | break; | |
240 | } | |
0475ac08 | 241 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
242 | return ret; /* (sighing) "Often!" */ |
243 | } | |
244 | ||
3e7cd6c4 | 245 | int is_current_pgrp_orphaned(void) |
1da177e4 LT |
246 | { |
247 | int retval; | |
248 | ||
249 | read_lock(&tasklist_lock); | |
3e7cd6c4 | 250 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL); |
1da177e4 LT |
251 | read_unlock(&tasklist_lock); |
252 | ||
253 | return retval; | |
254 | } | |
255 | ||
0475ac08 | 256 | static int has_stopped_jobs(struct pid *pgrp) |
1da177e4 LT |
257 | { |
258 | int retval = 0; | |
259 | struct task_struct *p; | |
260 | ||
0475ac08 | 261 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
262 | if (p->state != TASK_STOPPED) |
263 | continue; | |
1da177e4 LT |
264 | retval = 1; |
265 | break; | |
0475ac08 | 266 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
267 | return retval; |
268 | } | |
269 | ||
270 | /** | |
49d769d5 | 271 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd |
1da177e4 LT |
272 | * |
273 | * If a kernel thread is launched as a result of a system call, or if | |
49d769d5 EB |
274 | * it ever exits, it should generally reparent itself to kthreadd so it |
275 | * isn't in the way of other processes and is correctly cleaned up on exit. | |
1da177e4 LT |
276 | * |
277 | * The various task state such as scheduling policy and priority may have | |
278 | * been inherited from a user process, so we reset them to sane values here. | |
279 | * | |
49d769d5 | 280 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities. |
1da177e4 | 281 | */ |
49d769d5 | 282 | static void reparent_to_kthreadd(void) |
1da177e4 LT |
283 | { |
284 | write_lock_irq(&tasklist_lock); | |
285 | ||
286 | ptrace_unlink(current); | |
287 | /* Reparent to init */ | |
9b678ece | 288 | remove_parent(current); |
49d769d5 | 289 | current->real_parent = current->parent = kthreadd_task; |
9b678ece | 290 | add_parent(current); |
1da177e4 LT |
291 | |
292 | /* Set the exit signal to SIGCHLD so we signal init on exit */ | |
293 | current->exit_signal = SIGCHLD; | |
294 | ||
e05606d3 | 295 | if (task_nice(current) < 0) |
1da177e4 LT |
296 | set_user_nice(current, 0); |
297 | /* cpus_allowed? */ | |
298 | /* rt_priority? */ | |
299 | /* signals? */ | |
300 | security_task_reparent_to_init(current); | |
301 | memcpy(current->signal->rlim, init_task.signal->rlim, | |
302 | sizeof(current->signal->rlim)); | |
303 | atomic_inc(&(INIT_USER->__count)); | |
304 | write_unlock_irq(&tasklist_lock); | |
305 | switch_uid(INIT_USER); | |
306 | } | |
307 | ||
308 | void __set_special_pids(pid_t session, pid_t pgrp) | |
309 | { | |
e19f247a | 310 | struct task_struct *curr = current->group_leader; |
1da177e4 | 311 | |
937949d9 | 312 | if (process_session(curr) != session) { |
1da177e4 | 313 | detach_pid(curr, PIDTYPE_SID); |
1ec320af | 314 | set_signal_session(curr->signal, session); |
e713d0da | 315 | attach_pid(curr, PIDTYPE_SID, find_pid(session)); |
1da177e4 LT |
316 | } |
317 | if (process_group(curr) != pgrp) { | |
318 | detach_pid(curr, PIDTYPE_PGID); | |
319 | curr->signal->pgrp = pgrp; | |
e713d0da | 320 | attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp)); |
1da177e4 LT |
321 | } |
322 | } | |
323 | ||
ae424ae4 | 324 | static void set_special_pids(pid_t session, pid_t pgrp) |
1da177e4 LT |
325 | { |
326 | write_lock_irq(&tasklist_lock); | |
327 | __set_special_pids(session, pgrp); | |
328 | write_unlock_irq(&tasklist_lock); | |
329 | } | |
330 | ||
331 | /* | |
332 | * Let kernel threads use this to say that they | |
333 | * allow a certain signal (since daemonize() will | |
334 | * have disabled all of them by default). | |
335 | */ | |
336 | int allow_signal(int sig) | |
337 | { | |
7ed20e1a | 338 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
339 | return -EINVAL; |
340 | ||
341 | spin_lock_irq(¤t->sighand->siglock); | |
342 | sigdelset(¤t->blocked, sig); | |
343 | if (!current->mm) { | |
344 | /* Kernel threads handle their own signals. | |
345 | Let the signal code know it'll be handled, so | |
346 | that they don't get converted to SIGKILL or | |
347 | just silently dropped */ | |
348 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; | |
349 | } | |
350 | recalc_sigpending(); | |
351 | spin_unlock_irq(¤t->sighand->siglock); | |
352 | return 0; | |
353 | } | |
354 | ||
355 | EXPORT_SYMBOL(allow_signal); | |
356 | ||
357 | int disallow_signal(int sig) | |
358 | { | |
7ed20e1a | 359 | if (!valid_signal(sig) || sig < 1) |
1da177e4 LT |
360 | return -EINVAL; |
361 | ||
362 | spin_lock_irq(¤t->sighand->siglock); | |
10ab825b | 363 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; |
1da177e4 LT |
364 | recalc_sigpending(); |
365 | spin_unlock_irq(¤t->sighand->siglock); | |
366 | return 0; | |
367 | } | |
368 | ||
369 | EXPORT_SYMBOL(disallow_signal); | |
370 | ||
371 | /* | |
372 | * Put all the gunge required to become a kernel thread without | |
373 | * attached user resources in one place where it belongs. | |
374 | */ | |
375 | ||
376 | void daemonize(const char *name, ...) | |
377 | { | |
378 | va_list args; | |
379 | struct fs_struct *fs; | |
380 | sigset_t blocked; | |
381 | ||
382 | va_start(args, name); | |
383 | vsnprintf(current->comm, sizeof(current->comm), name, args); | |
384 | va_end(args); | |
385 | ||
386 | /* | |
387 | * If we were started as result of loading a module, close all of the | |
388 | * user space pages. We don't need them, and if we didn't close them | |
389 | * they would be locked into memory. | |
390 | */ | |
391 | exit_mm(current); | |
83144186 RW |
392 | /* |
393 | * We don't want to have TIF_FREEZE set if the system-wide hibernation | |
394 | * or suspend transition begins right now. | |
395 | */ | |
396 | current->flags |= PF_NOFREEZE; | |
1da177e4 LT |
397 | |
398 | set_special_pids(1, 1); | |
24ec839c | 399 | proc_clear_tty(current); |
1da177e4 LT |
400 | |
401 | /* Block and flush all signals */ | |
402 | sigfillset(&blocked); | |
403 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
404 | flush_signals(current); | |
405 | ||
406 | /* Become as one with the init task */ | |
407 | ||
408 | exit_fs(current); /* current->fs->count--; */ | |
409 | fs = init_task.fs; | |
410 | current->fs = fs; | |
411 | atomic_inc(&fs->count); | |
ab516013 | 412 | |
444f378b | 413 | exit_task_namespaces(current); |
ab516013 | 414 | current->nsproxy = init_task.nsproxy; |
ab516013 SH |
415 | get_task_namespaces(current); |
416 | ||
1da177e4 LT |
417 | exit_files(current); |
418 | current->files = init_task.files; | |
419 | atomic_inc(¤t->files->count); | |
420 | ||
49d769d5 | 421 | reparent_to_kthreadd(); |
1da177e4 LT |
422 | } |
423 | ||
424 | EXPORT_SYMBOL(daemonize); | |
425 | ||
858119e1 | 426 | static void close_files(struct files_struct * files) |
1da177e4 LT |
427 | { |
428 | int i, j; | |
badf1662 | 429 | struct fdtable *fdt; |
1da177e4 LT |
430 | |
431 | j = 0; | |
4fb3a538 DS |
432 | |
433 | /* | |
434 | * It is safe to dereference the fd table without RCU or | |
435 | * ->file_lock because this is the last reference to the | |
436 | * files structure. | |
437 | */ | |
badf1662 | 438 | fdt = files_fdtable(files); |
1da177e4 LT |
439 | for (;;) { |
440 | unsigned long set; | |
441 | i = j * __NFDBITS; | |
bbea9f69 | 442 | if (i >= fdt->max_fds) |
1da177e4 | 443 | break; |
badf1662 | 444 | set = fdt->open_fds->fds_bits[j++]; |
1da177e4 LT |
445 | while (set) { |
446 | if (set & 1) { | |
badf1662 | 447 | struct file * file = xchg(&fdt->fd[i], NULL); |
944be0b2 | 448 | if (file) { |
1da177e4 | 449 | filp_close(file, files); |
944be0b2 IM |
450 | cond_resched(); |
451 | } | |
1da177e4 LT |
452 | } |
453 | i++; | |
454 | set >>= 1; | |
455 | } | |
456 | } | |
457 | } | |
458 | ||
459 | struct files_struct *get_files_struct(struct task_struct *task) | |
460 | { | |
461 | struct files_struct *files; | |
462 | ||
463 | task_lock(task); | |
464 | files = task->files; | |
465 | if (files) | |
466 | atomic_inc(&files->count); | |
467 | task_unlock(task); | |
468 | ||
469 | return files; | |
470 | } | |
471 | ||
472 | void fastcall put_files_struct(struct files_struct *files) | |
473 | { | |
badf1662 DS |
474 | struct fdtable *fdt; |
475 | ||
1da177e4 LT |
476 | if (atomic_dec_and_test(&files->count)) { |
477 | close_files(files); | |
478 | /* | |
479 | * Free the fd and fdset arrays if we expanded them. | |
ab2af1f5 DS |
480 | * If the fdtable was embedded, pass files for freeing |
481 | * at the end of the RCU grace period. Otherwise, | |
482 | * you can free files immediately. | |
1da177e4 | 483 | */ |
badf1662 | 484 | fdt = files_fdtable(files); |
4fd45812 | 485 | if (fdt != &files->fdtab) |
ab2af1f5 | 486 | kmem_cache_free(files_cachep, files); |
01b2d93c | 487 | free_fdtable(fdt); |
1da177e4 LT |
488 | } |
489 | } | |
490 | ||
491 | EXPORT_SYMBOL(put_files_struct); | |
492 | ||
3b9b8ab6 KK |
493 | void reset_files_struct(struct task_struct *tsk, struct files_struct *files) |
494 | { | |
495 | struct files_struct *old; | |
496 | ||
497 | old = tsk->files; | |
498 | task_lock(tsk); | |
499 | tsk->files = files; | |
500 | task_unlock(tsk); | |
501 | put_files_struct(old); | |
502 | } | |
503 | EXPORT_SYMBOL(reset_files_struct); | |
504 | ||
1da177e4 LT |
505 | static inline void __exit_files(struct task_struct *tsk) |
506 | { | |
507 | struct files_struct * files = tsk->files; | |
508 | ||
509 | if (files) { | |
510 | task_lock(tsk); | |
511 | tsk->files = NULL; | |
512 | task_unlock(tsk); | |
513 | put_files_struct(files); | |
514 | } | |
515 | } | |
516 | ||
517 | void exit_files(struct task_struct *tsk) | |
518 | { | |
519 | __exit_files(tsk); | |
520 | } | |
521 | ||
522 | static inline void __put_fs_struct(struct fs_struct *fs) | |
523 | { | |
524 | /* No need to hold fs->lock if we are killing it */ | |
525 | if (atomic_dec_and_test(&fs->count)) { | |
526 | dput(fs->root); | |
527 | mntput(fs->rootmnt); | |
528 | dput(fs->pwd); | |
529 | mntput(fs->pwdmnt); | |
530 | if (fs->altroot) { | |
531 | dput(fs->altroot); | |
532 | mntput(fs->altrootmnt); | |
533 | } | |
534 | kmem_cache_free(fs_cachep, fs); | |
535 | } | |
536 | } | |
537 | ||
538 | void put_fs_struct(struct fs_struct *fs) | |
539 | { | |
540 | __put_fs_struct(fs); | |
541 | } | |
542 | ||
543 | static inline void __exit_fs(struct task_struct *tsk) | |
544 | { | |
545 | struct fs_struct * fs = tsk->fs; | |
546 | ||
547 | if (fs) { | |
548 | task_lock(tsk); | |
549 | tsk->fs = NULL; | |
550 | task_unlock(tsk); | |
551 | __put_fs_struct(fs); | |
552 | } | |
553 | } | |
554 | ||
555 | void exit_fs(struct task_struct *tsk) | |
556 | { | |
557 | __exit_fs(tsk); | |
558 | } | |
559 | ||
560 | EXPORT_SYMBOL_GPL(exit_fs); | |
561 | ||
562 | /* | |
563 | * Turn us into a lazy TLB process if we | |
564 | * aren't already.. | |
565 | */ | |
408b664a | 566 | static void exit_mm(struct task_struct * tsk) |
1da177e4 LT |
567 | { |
568 | struct mm_struct *mm = tsk->mm; | |
569 | ||
570 | mm_release(tsk, mm); | |
571 | if (!mm) | |
572 | return; | |
573 | /* | |
574 | * Serialize with any possible pending coredump. | |
575 | * We must hold mmap_sem around checking core_waiters | |
576 | * and clearing tsk->mm. The core-inducing thread | |
577 | * will increment core_waiters for each thread in the | |
578 | * group with ->mm != NULL. | |
579 | */ | |
580 | down_read(&mm->mmap_sem); | |
581 | if (mm->core_waiters) { | |
582 | up_read(&mm->mmap_sem); | |
583 | down_write(&mm->mmap_sem); | |
584 | if (!--mm->core_waiters) | |
585 | complete(mm->core_startup_done); | |
586 | up_write(&mm->mmap_sem); | |
587 | ||
588 | wait_for_completion(&mm->core_done); | |
589 | down_read(&mm->mmap_sem); | |
590 | } | |
591 | atomic_inc(&mm->mm_count); | |
125e1874 | 592 | BUG_ON(mm != tsk->active_mm); |
1da177e4 LT |
593 | /* more a memory barrier than a real lock */ |
594 | task_lock(tsk); | |
595 | tsk->mm = NULL; | |
596 | up_read(&mm->mmap_sem); | |
597 | enter_lazy_tlb(mm, current); | |
0c1eecfb RW |
598 | /* We don't want this task to be frozen prematurely */ |
599 | clear_freeze_flag(tsk); | |
1da177e4 LT |
600 | task_unlock(tsk); |
601 | mmput(mm); | |
602 | } | |
603 | ||
36c8b586 IM |
604 | static inline void |
605 | choose_new_parent(struct task_struct *p, struct task_struct *reaper) | |
1da177e4 LT |
606 | { |
607 | /* | |
608 | * Make sure we're not reparenting to ourselves and that | |
609 | * the parent is not a zombie. | |
610 | */ | |
d799f035 | 611 | BUG_ON(p == reaper || reaper->exit_state); |
1da177e4 | 612 | p->real_parent = reaper; |
1da177e4 LT |
613 | } |
614 | ||
36c8b586 IM |
615 | static void |
616 | reparent_thread(struct task_struct *p, struct task_struct *father, int traced) | |
1da177e4 | 617 | { |
241ceee0 ON |
618 | if (p->pdeath_signal) |
619 | /* We already hold the tasklist_lock here. */ | |
620 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | |
621 | ||
1da177e4 LT |
622 | /* Move the child from its dying parent to the new one. */ |
623 | if (unlikely(traced)) { | |
624 | /* Preserve ptrace links if someone else is tracing this child. */ | |
625 | list_del_init(&p->ptrace_list); | |
626 | if (p->parent != p->real_parent) | |
627 | list_add(&p->ptrace_list, &p->real_parent->ptrace_children); | |
628 | } else { | |
629 | /* If this child is being traced, then we're the one tracing it | |
630 | * anyway, so let go of it. | |
631 | */ | |
632 | p->ptrace = 0; | |
6ac781b1 | 633 | remove_parent(p); |
1da177e4 | 634 | p->parent = p->real_parent; |
6ac781b1 | 635 | add_parent(p); |
1da177e4 | 636 | |
b2b2cbc4 | 637 | if (p->state == TASK_TRACED) { |
1da177e4 LT |
638 | /* |
639 | * If it was at a trace stop, turn it into | |
640 | * a normal stop since it's no longer being | |
641 | * traced. | |
642 | */ | |
643 | ptrace_untrace(p); | |
644 | } | |
645 | } | |
646 | ||
b2b2cbc4 EB |
647 | /* If this is a threaded reparent there is no need to |
648 | * notify anyone anything has happened. | |
649 | */ | |
650 | if (p->real_parent->group_leader == father->group_leader) | |
651 | return; | |
652 | ||
653 | /* We don't want people slaying init. */ | |
654 | if (p->exit_signal != -1) | |
655 | p->exit_signal = SIGCHLD; | |
b2b2cbc4 EB |
656 | |
657 | /* If we'd notified the old parent about this child's death, | |
658 | * also notify the new parent. | |
659 | */ | |
660 | if (!traced && p->exit_state == EXIT_ZOMBIE && | |
661 | p->exit_signal != -1 && thread_group_empty(p)) | |
662 | do_notify_parent(p, p->exit_signal); | |
663 | ||
1da177e4 LT |
664 | /* |
665 | * process group orphan check | |
666 | * Case ii: Our child is in a different pgrp | |
667 | * than we are, and it was the only connection | |
668 | * outside, so the child pgrp is now orphaned. | |
669 | */ | |
0475ac08 EB |
670 | if ((task_pgrp(p) != task_pgrp(father)) && |
671 | (task_session(p) == task_session(father))) { | |
672 | struct pid *pgrp = task_pgrp(p); | |
1da177e4 | 673 | |
937949d9 CLG |
674 | if (will_become_orphaned_pgrp(pgrp, NULL) && |
675 | has_stopped_jobs(pgrp)) { | |
0475ac08 EB |
676 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); |
677 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
1da177e4 LT |
678 | } |
679 | } | |
680 | } | |
681 | ||
682 | /* | |
683 | * When we die, we re-parent all our children. | |
684 | * Try to give them to another thread in our thread | |
685 | * group, and if no such member exists, give it to | |
84d73786 SB |
686 | * the child reaper process (ie "init") in our pid |
687 | * space. | |
1da177e4 | 688 | */ |
36c8b586 IM |
689 | static void |
690 | forget_original_parent(struct task_struct *father, struct list_head *to_release) | |
1da177e4 LT |
691 | { |
692 | struct task_struct *p, *reaper = father; | |
693 | struct list_head *_p, *_n; | |
694 | ||
695 | do { | |
696 | reaper = next_thread(reaper); | |
697 | if (reaper == father) { | |
84d73786 | 698 | reaper = child_reaper(father); |
1da177e4 LT |
699 | break; |
700 | } | |
701 | } while (reaper->exit_state); | |
702 | ||
703 | /* | |
704 | * There are only two places where our children can be: | |
705 | * | |
706 | * - in our child list | |
707 | * - in our ptraced child list | |
708 | * | |
709 | * Search them and reparent children. | |
710 | */ | |
711 | list_for_each_safe(_p, _n, &father->children) { | |
712 | int ptrace; | |
36c8b586 | 713 | p = list_entry(_p, struct task_struct, sibling); |
1da177e4 LT |
714 | |
715 | ptrace = p->ptrace; | |
716 | ||
717 | /* if father isn't the real parent, then ptrace must be enabled */ | |
718 | BUG_ON(father != p->real_parent && !ptrace); | |
719 | ||
720 | if (father == p->real_parent) { | |
721 | /* reparent with a reaper, real father it's us */ | |
d799f035 | 722 | choose_new_parent(p, reaper); |
1da177e4 LT |
723 | reparent_thread(p, father, 0); |
724 | } else { | |
725 | /* reparent ptraced task to its real parent */ | |
726 | __ptrace_unlink (p); | |
727 | if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 && | |
728 | thread_group_empty(p)) | |
729 | do_notify_parent(p, p->exit_signal); | |
730 | } | |
731 | ||
732 | /* | |
733 | * if the ptraced child is a zombie with exit_signal == -1 | |
734 | * we must collect it before we exit, or it will remain | |
735 | * zombie forever since we prevented it from self-reap itself | |
736 | * while it was being traced by us, to be able to see it in wait4. | |
737 | */ | |
738 | if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1)) | |
739 | list_add(&p->ptrace_list, to_release); | |
740 | } | |
741 | list_for_each_safe(_p, _n, &father->ptrace_children) { | |
36c8b586 | 742 | p = list_entry(_p, struct task_struct, ptrace_list); |
d799f035 | 743 | choose_new_parent(p, reaper); |
1da177e4 LT |
744 | reparent_thread(p, father, 1); |
745 | } | |
746 | } | |
747 | ||
748 | /* | |
749 | * Send signals to all our closest relatives so that they know | |
750 | * to properly mourn us.. | |
751 | */ | |
752 | static void exit_notify(struct task_struct *tsk) | |
753 | { | |
754 | int state; | |
755 | struct task_struct *t; | |
756 | struct list_head ptrace_dead, *_p, *_n; | |
0475ac08 | 757 | struct pid *pgrp; |
1da177e4 LT |
758 | |
759 | if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT) | |
760 | && !thread_group_empty(tsk)) { | |
761 | /* | |
762 | * This occurs when there was a race between our exit | |
763 | * syscall and a group signal choosing us as the one to | |
764 | * wake up. It could be that we are the only thread | |
765 | * alerted to check for pending signals, but another thread | |
766 | * should be woken now to take the signal since we will not. | |
767 | * Now we'll wake all the threads in the group just to make | |
768 | * sure someone gets all the pending signals. | |
769 | */ | |
770 | read_lock(&tasklist_lock); | |
771 | spin_lock_irq(&tsk->sighand->siglock); | |
772 | for (t = next_thread(tsk); t != tsk; t = next_thread(t)) | |
7bb44ade RM |
773 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) |
774 | recalc_sigpending_and_wake(t); | |
1da177e4 LT |
775 | spin_unlock_irq(&tsk->sighand->siglock); |
776 | read_unlock(&tasklist_lock); | |
777 | } | |
778 | ||
779 | write_lock_irq(&tasklist_lock); | |
780 | ||
781 | /* | |
782 | * This does two things: | |
783 | * | |
784 | * A. Make init inherit all the child processes | |
785 | * B. Check to see if any process groups have become orphaned | |
786 | * as a result of our exiting, and if they have any stopped | |
787 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
788 | */ | |
789 | ||
790 | INIT_LIST_HEAD(&ptrace_dead); | |
791 | forget_original_parent(tsk, &ptrace_dead); | |
792 | BUG_ON(!list_empty(&tsk->children)); | |
793 | BUG_ON(!list_empty(&tsk->ptrace_children)); | |
794 | ||
795 | /* | |
796 | * Check to see if any process groups have become orphaned | |
797 | * as a result of our exiting, and if they have any stopped | |
798 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) | |
799 | * | |
800 | * Case i: Our father is in a different pgrp than we are | |
801 | * and we were the only connection outside, so our pgrp | |
802 | * is about to become orphaned. | |
803 | */ | |
804 | ||
805 | t = tsk->real_parent; | |
806 | ||
0475ac08 EB |
807 | pgrp = task_pgrp(tsk); |
808 | if ((task_pgrp(t) != pgrp) && | |
14e9d573 | 809 | (task_session(t) == task_session(tsk)) && |
0475ac08 EB |
810 | will_become_orphaned_pgrp(pgrp, tsk) && |
811 | has_stopped_jobs(pgrp)) { | |
812 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp); | |
813 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); | |
1da177e4 LT |
814 | } |
815 | ||
816 | /* Let father know we died | |
817 | * | |
818 | * Thread signals are configurable, but you aren't going to use | |
819 | * that to send signals to arbitary processes. | |
820 | * That stops right now. | |
821 | * | |
822 | * If the parent exec id doesn't match the exec id we saved | |
823 | * when we started then we know the parent has changed security | |
824 | * domain. | |
825 | * | |
826 | * If our self_exec id doesn't match our parent_exec_id then | |
827 | * we have changed execution domain as these two values started | |
828 | * the same after a fork. | |
829 | * | |
830 | */ | |
831 | ||
832 | if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 && | |
833 | ( tsk->parent_exec_id != t->self_exec_id || | |
834 | tsk->self_exec_id != tsk->parent_exec_id) | |
835 | && !capable(CAP_KILL)) | |
836 | tsk->exit_signal = SIGCHLD; | |
837 | ||
838 | ||
839 | /* If something other than our normal parent is ptracing us, then | |
840 | * send it a SIGCHLD instead of honoring exit_signal. exit_signal | |
841 | * only has special meaning to our real parent. | |
842 | */ | |
843 | if (tsk->exit_signal != -1 && thread_group_empty(tsk)) { | |
844 | int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD; | |
845 | do_notify_parent(tsk, signal); | |
846 | } else if (tsk->ptrace) { | |
847 | do_notify_parent(tsk, SIGCHLD); | |
848 | } | |
849 | ||
850 | state = EXIT_ZOMBIE; | |
851 | if (tsk->exit_signal == -1 && | |
852 | (likely(tsk->ptrace == 0) || | |
853 | unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT))) | |
854 | state = EXIT_DEAD; | |
855 | tsk->exit_state = state; | |
856 | ||
857 | write_unlock_irq(&tasklist_lock); | |
858 | ||
859 | list_for_each_safe(_p, _n, &ptrace_dead) { | |
860 | list_del_init(_p); | |
36c8b586 | 861 | t = list_entry(_p, struct task_struct, ptrace_list); |
1da177e4 LT |
862 | release_task(t); |
863 | } | |
864 | ||
865 | /* If the process is dead, release it - nobody will wait for it */ | |
866 | if (state == EXIT_DEAD) | |
867 | release_task(tsk); | |
1da177e4 LT |
868 | } |
869 | ||
e18eecb8 JD |
870 | #ifdef CONFIG_DEBUG_STACK_USAGE |
871 | static void check_stack_usage(void) | |
872 | { | |
873 | static DEFINE_SPINLOCK(low_water_lock); | |
874 | static int lowest_to_date = THREAD_SIZE; | |
875 | unsigned long *n = end_of_stack(current); | |
876 | unsigned long free; | |
877 | ||
878 | while (*n == 0) | |
879 | n++; | |
880 | free = (unsigned long)n - (unsigned long)end_of_stack(current); | |
881 | ||
882 | if (free >= lowest_to_date) | |
883 | return; | |
884 | ||
885 | spin_lock(&low_water_lock); | |
886 | if (free < lowest_to_date) { | |
887 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " | |
888 | "left\n", | |
889 | current->comm, free); | |
890 | lowest_to_date = free; | |
891 | } | |
892 | spin_unlock(&low_water_lock); | |
893 | } | |
894 | #else | |
895 | static inline void check_stack_usage(void) {} | |
896 | #endif | |
897 | ||
1da177e4 LT |
898 | fastcall NORET_TYPE void do_exit(long code) |
899 | { | |
900 | struct task_struct *tsk = current; | |
901 | int group_dead; | |
902 | ||
903 | profile_task_exit(tsk); | |
904 | ||
22e2c507 JA |
905 | WARN_ON(atomic_read(&tsk->fs_excl)); |
906 | ||
1da177e4 LT |
907 | if (unlikely(in_interrupt())) |
908 | panic("Aiee, killing interrupt handler!"); | |
909 | if (unlikely(!tsk->pid)) | |
910 | panic("Attempted to kill the idle task!"); | |
84d73786 SB |
911 | if (unlikely(tsk == child_reaper(tsk))) { |
912 | if (tsk->nsproxy->pid_ns != &init_pid_ns) | |
913 | tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper; | |
914 | else | |
915 | panic("Attempted to kill init!"); | |
916 | } | |
917 | ||
1da177e4 LT |
918 | |
919 | if (unlikely(current->ptrace & PT_TRACE_EXIT)) { | |
920 | current->ptrace_message = code; | |
921 | ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); | |
922 | } | |
923 | ||
df164db5 AN |
924 | /* |
925 | * We're taking recursive faults here in do_exit. Safest is to just | |
926 | * leave this task alone and wait for reboot. | |
927 | */ | |
928 | if (unlikely(tsk->flags & PF_EXITING)) { | |
929 | printk(KERN_ALERT | |
930 | "Fixing recursive fault but reboot is needed!\n"); | |
778e9a9c AK |
931 | /* |
932 | * We can do this unlocked here. The futex code uses | |
933 | * this flag just to verify whether the pi state | |
934 | * cleanup has been done or not. In the worst case it | |
935 | * loops once more. We pretend that the cleanup was | |
936 | * done as there is no way to return. Either the | |
937 | * OWNER_DIED bit is set by now or we push the blocked | |
938 | * task into the wait for ever nirwana as well. | |
939 | */ | |
940 | tsk->flags |= PF_EXITPIDONE; | |
afc847b7 AV |
941 | if (tsk->io_context) |
942 | exit_io_context(); | |
df164db5 AN |
943 | set_current_state(TASK_UNINTERRUPTIBLE); |
944 | schedule(); | |
945 | } | |
946 | ||
778e9a9c AK |
947 | /* |
948 | * tsk->flags are checked in the futex code to protect against | |
949 | * an exiting task cleaning up the robust pi futexes. | |
950 | */ | |
951 | spin_lock_irq(&tsk->pi_lock); | |
1da177e4 | 952 | tsk->flags |= PF_EXITING; |
778e9a9c | 953 | spin_unlock_irq(&tsk->pi_lock); |
1da177e4 | 954 | |
1da177e4 LT |
955 | if (unlikely(in_atomic())) |
956 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", | |
957 | current->comm, current->pid, | |
958 | preempt_count()); | |
959 | ||
960 | acct_update_integrals(tsk); | |
365e9c87 HD |
961 | if (tsk->mm) { |
962 | update_hiwater_rss(tsk->mm); | |
963 | update_hiwater_vm(tsk->mm); | |
964 | } | |
1da177e4 | 965 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
c3068951 | 966 | if (group_dead) { |
778e9a9c | 967 | hrtimer_cancel(&tsk->signal->real_timer); |
25f407f0 | 968 | exit_itimers(tsk->signal); |
c3068951 | 969 | } |
f6ec29a4 | 970 | acct_collect(code, group_dead); |
0771dfef IM |
971 | if (unlikely(tsk->robust_list)) |
972 | exit_robust_list(tsk); | |
2aa92581 | 973 | #if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT) |
34f192c6 IM |
974 | if (unlikely(tsk->compat_robust_list)) |
975 | compat_exit_robust_list(tsk); | |
976 | #endif | |
522ed776 MT |
977 | if (group_dead) |
978 | tty_audit_exit(); | |
fa84cb93 AV |
979 | if (unlikely(tsk->audit_context)) |
980 | audit_free(tsk); | |
115085ea ON |
981 | |
982 | taskstats_exit(tsk, group_dead); | |
c757249a | 983 | |
1da177e4 LT |
984 | exit_mm(tsk); |
985 | ||
0e464814 | 986 | if (group_dead) |
f6ec29a4 | 987 | acct_process(); |
1da177e4 LT |
988 | exit_sem(tsk); |
989 | __exit_files(tsk); | |
990 | __exit_fs(tsk); | |
e18eecb8 | 991 | check_stack_usage(); |
1da177e4 LT |
992 | exit_thread(); |
993 | cpuset_exit(tsk); | |
994 | exit_keys(tsk); | |
995 | ||
996 | if (group_dead && tsk->signal->leader) | |
997 | disassociate_ctty(1); | |
998 | ||
a1261f54 | 999 | module_put(task_thread_info(tsk)->exec_domain->module); |
1da177e4 LT |
1000 | if (tsk->binfmt) |
1001 | module_put(tsk->binfmt->module); | |
1002 | ||
1003 | tsk->exit_code = code; | |
9f46080c | 1004 | proc_exit_connector(tsk); |
444f378b | 1005 | exit_task_namespaces(tsk); |
0f245285 | 1006 | exit_notify(tsk); |
1da177e4 LT |
1007 | #ifdef CONFIG_NUMA |
1008 | mpol_free(tsk->mempolicy); | |
1009 | tsk->mempolicy = NULL; | |
1010 | #endif | |
c87e2837 IM |
1011 | /* |
1012 | * This must happen late, after the PID is not | |
1013 | * hashed anymore: | |
1014 | */ | |
1015 | if (unlikely(!list_empty(&tsk->pi_state_list))) | |
1016 | exit_pi_state_list(tsk); | |
1017 | if (unlikely(current->pi_state_cache)) | |
1018 | kfree(current->pi_state_cache); | |
de5097c2 | 1019 | /* |
9a11b49a | 1020 | * Make sure we are holding no locks: |
de5097c2 | 1021 | */ |
9a11b49a | 1022 | debug_check_no_locks_held(tsk); |
778e9a9c AK |
1023 | /* |
1024 | * We can do this unlocked here. The futex code uses this flag | |
1025 | * just to verify whether the pi state cleanup has been done | |
1026 | * or not. In the worst case it loops once more. | |
1027 | */ | |
1028 | tsk->flags |= PF_EXITPIDONE; | |
1da177e4 | 1029 | |
afc847b7 AV |
1030 | if (tsk->io_context) |
1031 | exit_io_context(); | |
1032 | ||
b92ce558 JA |
1033 | if (tsk->splice_pipe) |
1034 | __free_pipe_info(tsk->splice_pipe); | |
1035 | ||
7407251a | 1036 | preempt_disable(); |
55a101f8 | 1037 | /* causes final put_task_struct in finish_task_switch(). */ |
c394cc9f | 1038 | tsk->state = TASK_DEAD; |
7407251a | 1039 | |
1da177e4 LT |
1040 | schedule(); |
1041 | BUG(); | |
1042 | /* Avoid "noreturn function does return". */ | |
54306cf0 AC |
1043 | for (;;) |
1044 | cpu_relax(); /* For when BUG is null */ | |
1da177e4 LT |
1045 | } |
1046 | ||
012914da RA |
1047 | EXPORT_SYMBOL_GPL(do_exit); |
1048 | ||
1da177e4 LT |
1049 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
1050 | { | |
1051 | if (comp) | |
1052 | complete(comp); | |
55a101f8 | 1053 | |
1da177e4 LT |
1054 | do_exit(code); |
1055 | } | |
1056 | ||
1057 | EXPORT_SYMBOL(complete_and_exit); | |
1058 | ||
1059 | asmlinkage long sys_exit(int error_code) | |
1060 | { | |
1061 | do_exit((error_code&0xff)<<8); | |
1062 | } | |
1063 | ||
1da177e4 LT |
1064 | /* |
1065 | * Take down every thread in the group. This is called by fatal signals | |
1066 | * as well as by sys_exit_group (below). | |
1067 | */ | |
1068 | NORET_TYPE void | |
1069 | do_group_exit(int exit_code) | |
1070 | { | |
1071 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ | |
1072 | ||
1073 | if (current->signal->flags & SIGNAL_GROUP_EXIT) | |
1074 | exit_code = current->signal->group_exit_code; | |
1075 | else if (!thread_group_empty(current)) { | |
1076 | struct signal_struct *const sig = current->signal; | |
1077 | struct sighand_struct *const sighand = current->sighand; | |
1da177e4 LT |
1078 | spin_lock_irq(&sighand->siglock); |
1079 | if (sig->flags & SIGNAL_GROUP_EXIT) | |
1080 | /* Another thread got here before we took the lock. */ | |
1081 | exit_code = sig->group_exit_code; | |
1082 | else { | |
1da177e4 LT |
1083 | sig->group_exit_code = exit_code; |
1084 | zap_other_threads(current); | |
1085 | } | |
1086 | spin_unlock_irq(&sighand->siglock); | |
1da177e4 LT |
1087 | } |
1088 | ||
1089 | do_exit(exit_code); | |
1090 | /* NOTREACHED */ | |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * this kills every thread in the thread group. Note that any externally | |
1095 | * wait4()-ing process will get the correct exit code - even if this | |
1096 | * thread is not the thread group leader. | |
1097 | */ | |
1098 | asmlinkage void sys_exit_group(int error_code) | |
1099 | { | |
1100 | do_group_exit((error_code & 0xff) << 8); | |
1101 | } | |
1102 | ||
36c8b586 | 1103 | static int eligible_child(pid_t pid, int options, struct task_struct *p) |
1da177e4 | 1104 | { |
73243284 RM |
1105 | int err; |
1106 | ||
1da177e4 LT |
1107 | if (pid > 0) { |
1108 | if (p->pid != pid) | |
1109 | return 0; | |
1110 | } else if (!pid) { | |
1111 | if (process_group(p) != process_group(current)) | |
1112 | return 0; | |
1113 | } else if (pid != -1) { | |
1114 | if (process_group(p) != -pid) | |
1115 | return 0; | |
1116 | } | |
1117 | ||
1118 | /* | |
1119 | * Do not consider detached threads that are | |
1120 | * not ptraced: | |
1121 | */ | |
1122 | if (p->exit_signal == -1 && !p->ptrace) | |
1123 | return 0; | |
1124 | ||
1125 | /* Wait for all children (clone and not) if __WALL is set; | |
1126 | * otherwise, wait for clone children *only* if __WCLONE is | |
1127 | * set; otherwise, wait for non-clone children *only*. (Note: | |
1128 | * A "clone" child here is one that reports to its parent | |
1129 | * using a signal other than SIGCHLD.) */ | |
1130 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) | |
1131 | && !(options & __WALL)) | |
1132 | return 0; | |
1133 | /* | |
1134 | * Do not consider thread group leaders that are | |
1135 | * in a non-empty thread group: | |
1136 | */ | |
3b6362b8 | 1137 | if (delay_group_leader(p)) |
1da177e4 LT |
1138 | return 2; |
1139 | ||
73243284 RM |
1140 | err = security_task_wait(p); |
1141 | if (err) | |
1142 | return err; | |
1da177e4 LT |
1143 | |
1144 | return 1; | |
1145 | } | |
1146 | ||
36c8b586 | 1147 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
1da177e4 LT |
1148 | int why, int status, |
1149 | struct siginfo __user *infop, | |
1150 | struct rusage __user *rusagep) | |
1151 | { | |
1152 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; | |
36c8b586 | 1153 | |
1da177e4 LT |
1154 | put_task_struct(p); |
1155 | if (!retval) | |
1156 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1157 | if (!retval) | |
1158 | retval = put_user(0, &infop->si_errno); | |
1159 | if (!retval) | |
1160 | retval = put_user((short)why, &infop->si_code); | |
1161 | if (!retval) | |
1162 | retval = put_user(pid, &infop->si_pid); | |
1163 | if (!retval) | |
1164 | retval = put_user(uid, &infop->si_uid); | |
1165 | if (!retval) | |
1166 | retval = put_user(status, &infop->si_status); | |
1167 | if (!retval) | |
1168 | retval = pid; | |
1169 | return retval; | |
1170 | } | |
1171 | ||
1172 | /* | |
1173 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold | |
1174 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1175 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1176 | * released the lock and the system call should return. | |
1177 | */ | |
36c8b586 | 1178 | static int wait_task_zombie(struct task_struct *p, int noreap, |
1da177e4 LT |
1179 | struct siginfo __user *infop, |
1180 | int __user *stat_addr, struct rusage __user *ru) | |
1181 | { | |
1182 | unsigned long state; | |
1183 | int retval; | |
1184 | int status; | |
1185 | ||
1186 | if (unlikely(noreap)) { | |
1187 | pid_t pid = p->pid; | |
1188 | uid_t uid = p->uid; | |
1189 | int exit_code = p->exit_code; | |
1190 | int why, status; | |
1191 | ||
1192 | if (unlikely(p->exit_state != EXIT_ZOMBIE)) | |
1193 | return 0; | |
1194 | if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) | |
1195 | return 0; | |
1196 | get_task_struct(p); | |
1197 | read_unlock(&tasklist_lock); | |
1198 | if ((exit_code & 0x7f) == 0) { | |
1199 | why = CLD_EXITED; | |
1200 | status = exit_code >> 8; | |
1201 | } else { | |
1202 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1203 | status = exit_code & 0x7f; | |
1204 | } | |
1205 | return wait_noreap_copyout(p, pid, uid, why, | |
1206 | status, infop, ru); | |
1207 | } | |
1208 | ||
1209 | /* | |
1210 | * Try to move the task's state to DEAD | |
1211 | * only one thread is allowed to do this: | |
1212 | */ | |
1213 | state = xchg(&p->exit_state, EXIT_DEAD); | |
1214 | if (state != EXIT_ZOMBIE) { | |
1215 | BUG_ON(state != EXIT_DEAD); | |
1216 | return 0; | |
1217 | } | |
1218 | if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) { | |
1219 | /* | |
1220 | * This can only happen in a race with a ptraced thread | |
1221 | * dying on another processor. | |
1222 | */ | |
1223 | return 0; | |
1224 | } | |
1225 | ||
1226 | if (likely(p->real_parent == p->parent) && likely(p->signal)) { | |
3795e161 JJ |
1227 | struct signal_struct *psig; |
1228 | struct signal_struct *sig; | |
1229 | ||
1da177e4 LT |
1230 | /* |
1231 | * The resource counters for the group leader are in its | |
1232 | * own task_struct. Those for dead threads in the group | |
1233 | * are in its signal_struct, as are those for the child | |
1234 | * processes it has previously reaped. All these | |
1235 | * accumulate in the parent's signal_struct c* fields. | |
1236 | * | |
1237 | * We don't bother to take a lock here to protect these | |
1238 | * p->signal fields, because they are only touched by | |
1239 | * __exit_signal, which runs with tasklist_lock | |
1240 | * write-locked anyway, and so is excluded here. We do | |
1241 | * need to protect the access to p->parent->signal fields, | |
1242 | * as other threads in the parent group can be right | |
1243 | * here reaping other children at the same time. | |
1244 | */ | |
1245 | spin_lock_irq(&p->parent->sighand->siglock); | |
3795e161 JJ |
1246 | psig = p->parent->signal; |
1247 | sig = p->signal; | |
1248 | psig->cutime = | |
1249 | cputime_add(psig->cutime, | |
1da177e4 | 1250 | cputime_add(p->utime, |
3795e161 JJ |
1251 | cputime_add(sig->utime, |
1252 | sig->cutime))); | |
1253 | psig->cstime = | |
1254 | cputime_add(psig->cstime, | |
1da177e4 | 1255 | cputime_add(p->stime, |
3795e161 JJ |
1256 | cputime_add(sig->stime, |
1257 | sig->cstime))); | |
1258 | psig->cmin_flt += | |
1259 | p->min_flt + sig->min_flt + sig->cmin_flt; | |
1260 | psig->cmaj_flt += | |
1261 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; | |
1262 | psig->cnvcsw += | |
1263 | p->nvcsw + sig->nvcsw + sig->cnvcsw; | |
1264 | psig->cnivcsw += | |
1265 | p->nivcsw + sig->nivcsw + sig->cnivcsw; | |
6eaeeaba ED |
1266 | psig->cinblock += |
1267 | task_io_get_inblock(p) + | |
1268 | sig->inblock + sig->cinblock; | |
1269 | psig->coublock += | |
1270 | task_io_get_oublock(p) + | |
1271 | sig->oublock + sig->coublock; | |
1da177e4 LT |
1272 | spin_unlock_irq(&p->parent->sighand->siglock); |
1273 | } | |
1274 | ||
1275 | /* | |
1276 | * Now we are sure this task is interesting, and no other | |
1277 | * thread can reap it because we set its state to EXIT_DEAD. | |
1278 | */ | |
1279 | read_unlock(&tasklist_lock); | |
1280 | ||
1281 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1282 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) | |
1283 | ? p->signal->group_exit_code : p->exit_code; | |
1284 | if (!retval && stat_addr) | |
1285 | retval = put_user(status, stat_addr); | |
1286 | if (!retval && infop) | |
1287 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1288 | if (!retval && infop) | |
1289 | retval = put_user(0, &infop->si_errno); | |
1290 | if (!retval && infop) { | |
1291 | int why; | |
1292 | ||
1293 | if ((status & 0x7f) == 0) { | |
1294 | why = CLD_EXITED; | |
1295 | status >>= 8; | |
1296 | } else { | |
1297 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; | |
1298 | status &= 0x7f; | |
1299 | } | |
1300 | retval = put_user((short)why, &infop->si_code); | |
1301 | if (!retval) | |
1302 | retval = put_user(status, &infop->si_status); | |
1303 | } | |
1304 | if (!retval && infop) | |
1305 | retval = put_user(p->pid, &infop->si_pid); | |
1306 | if (!retval && infop) | |
1307 | retval = put_user(p->uid, &infop->si_uid); | |
1308 | if (retval) { | |
1309 | // TODO: is this safe? | |
1310 | p->exit_state = EXIT_ZOMBIE; | |
1311 | return retval; | |
1312 | } | |
1313 | retval = p->pid; | |
1314 | if (p->real_parent != p->parent) { | |
1315 | write_lock_irq(&tasklist_lock); | |
1316 | /* Double-check with lock held. */ | |
1317 | if (p->real_parent != p->parent) { | |
1318 | __ptrace_unlink(p); | |
1319 | // TODO: is this safe? | |
1320 | p->exit_state = EXIT_ZOMBIE; | |
1321 | /* | |
1322 | * If this is not a detached task, notify the parent. | |
1323 | * If it's still not detached after that, don't release | |
1324 | * it now. | |
1325 | */ | |
1326 | if (p->exit_signal != -1) { | |
1327 | do_notify_parent(p, p->exit_signal); | |
1328 | if (p->exit_signal != -1) | |
1329 | p = NULL; | |
1330 | } | |
1331 | } | |
1332 | write_unlock_irq(&tasklist_lock); | |
1333 | } | |
1334 | if (p != NULL) | |
1335 | release_task(p); | |
1336 | BUG_ON(!retval); | |
1337 | return retval; | |
1338 | } | |
1339 | ||
1340 | /* | |
1341 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | |
1342 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1343 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1344 | * released the lock and the system call should return. | |
1345 | */ | |
36c8b586 IM |
1346 | static int wait_task_stopped(struct task_struct *p, int delayed_group_leader, |
1347 | int noreap, struct siginfo __user *infop, | |
1da177e4 LT |
1348 | int __user *stat_addr, struct rusage __user *ru) |
1349 | { | |
1350 | int retval, exit_code; | |
1351 | ||
1352 | if (!p->exit_code) | |
1353 | return 0; | |
1354 | if (delayed_group_leader && !(p->ptrace & PT_PTRACED) && | |
1355 | p->signal && p->signal->group_stop_count > 0) | |
1356 | /* | |
1357 | * A group stop is in progress and this is the group leader. | |
1358 | * We won't report until all threads have stopped. | |
1359 | */ | |
1360 | return 0; | |
1361 | ||
1362 | /* | |
1363 | * Now we are pretty sure this task is interesting. | |
1364 | * Make sure it doesn't get reaped out from under us while we | |
1365 | * give up the lock and then examine it below. We don't want to | |
1366 | * keep holding onto the tasklist_lock while we call getrusage and | |
1367 | * possibly take page faults for user memory. | |
1368 | */ | |
1369 | get_task_struct(p); | |
1370 | read_unlock(&tasklist_lock); | |
1371 | ||
1372 | if (unlikely(noreap)) { | |
1373 | pid_t pid = p->pid; | |
1374 | uid_t uid = p->uid; | |
1375 | int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; | |
1376 | ||
1377 | exit_code = p->exit_code; | |
1378 | if (unlikely(!exit_code) || | |
14bf01bb | 1379 | unlikely(p->state & TASK_TRACED)) |
1da177e4 LT |
1380 | goto bail_ref; |
1381 | return wait_noreap_copyout(p, pid, uid, | |
1382 | why, (exit_code << 8) | 0x7f, | |
1383 | infop, ru); | |
1384 | } | |
1385 | ||
1386 | write_lock_irq(&tasklist_lock); | |
1387 | ||
1388 | /* | |
1389 | * This uses xchg to be atomic with the thread resuming and setting | |
1390 | * it. It must also be done with the write lock held to prevent a | |
1391 | * race with the EXIT_ZOMBIE case. | |
1392 | */ | |
1393 | exit_code = xchg(&p->exit_code, 0); | |
1394 | if (unlikely(p->exit_state)) { | |
1395 | /* | |
1396 | * The task resumed and then died. Let the next iteration | |
1397 | * catch it in EXIT_ZOMBIE. Note that exit_code might | |
1398 | * already be zero here if it resumed and did _exit(0). | |
1399 | * The task itself is dead and won't touch exit_code again; | |
1400 | * other processors in this function are locked out. | |
1401 | */ | |
1402 | p->exit_code = exit_code; | |
1403 | exit_code = 0; | |
1404 | } | |
1405 | if (unlikely(exit_code == 0)) { | |
1406 | /* | |
1407 | * Another thread in this function got to it first, or it | |
1408 | * resumed, or it resumed and then died. | |
1409 | */ | |
1410 | write_unlock_irq(&tasklist_lock); | |
1411 | bail_ref: | |
1412 | put_task_struct(p); | |
1413 | /* | |
1414 | * We are returning to the wait loop without having successfully | |
1415 | * removed the process and having released the lock. We cannot | |
1416 | * continue, since the "p" task pointer is potentially stale. | |
1417 | * | |
1418 | * Return -EAGAIN, and do_wait() will restart the loop from the | |
1419 | * beginning. Do _not_ re-acquire the lock. | |
1420 | */ | |
1421 | return -EAGAIN; | |
1422 | } | |
1423 | ||
1424 | /* move to end of parent's list to avoid starvation */ | |
1425 | remove_parent(p); | |
8fafabd8 | 1426 | add_parent(p); |
1da177e4 LT |
1427 | |
1428 | write_unlock_irq(&tasklist_lock); | |
1429 | ||
1430 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1431 | if (!retval && stat_addr) | |
1432 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); | |
1433 | if (!retval && infop) | |
1434 | retval = put_user(SIGCHLD, &infop->si_signo); | |
1435 | if (!retval && infop) | |
1436 | retval = put_user(0, &infop->si_errno); | |
1437 | if (!retval && infop) | |
1438 | retval = put_user((short)((p->ptrace & PT_PTRACED) | |
1439 | ? CLD_TRAPPED : CLD_STOPPED), | |
1440 | &infop->si_code); | |
1441 | if (!retval && infop) | |
1442 | retval = put_user(exit_code, &infop->si_status); | |
1443 | if (!retval && infop) | |
1444 | retval = put_user(p->pid, &infop->si_pid); | |
1445 | if (!retval && infop) | |
1446 | retval = put_user(p->uid, &infop->si_uid); | |
1447 | if (!retval) | |
1448 | retval = p->pid; | |
1449 | put_task_struct(p); | |
1450 | ||
1451 | BUG_ON(!retval); | |
1452 | return retval; | |
1453 | } | |
1454 | ||
1455 | /* | |
1456 | * Handle do_wait work for one task in a live, non-stopped state. | |
1457 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | |
1458 | * the lock and this task is uninteresting. If we return nonzero, we have | |
1459 | * released the lock and the system call should return. | |
1460 | */ | |
36c8b586 | 1461 | static int wait_task_continued(struct task_struct *p, int noreap, |
1da177e4 LT |
1462 | struct siginfo __user *infop, |
1463 | int __user *stat_addr, struct rusage __user *ru) | |
1464 | { | |
1465 | int retval; | |
1466 | pid_t pid; | |
1467 | uid_t uid; | |
1468 | ||
1469 | if (unlikely(!p->signal)) | |
1470 | return 0; | |
1471 | ||
1472 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) | |
1473 | return 0; | |
1474 | ||
1475 | spin_lock_irq(&p->sighand->siglock); | |
1476 | /* Re-check with the lock held. */ | |
1477 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { | |
1478 | spin_unlock_irq(&p->sighand->siglock); | |
1479 | return 0; | |
1480 | } | |
1481 | if (!noreap) | |
1482 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; | |
1483 | spin_unlock_irq(&p->sighand->siglock); | |
1484 | ||
1485 | pid = p->pid; | |
1486 | uid = p->uid; | |
1487 | get_task_struct(p); | |
1488 | read_unlock(&tasklist_lock); | |
1489 | ||
1490 | if (!infop) { | |
1491 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; | |
1492 | put_task_struct(p); | |
1493 | if (!retval && stat_addr) | |
1494 | retval = put_user(0xffff, stat_addr); | |
1495 | if (!retval) | |
1496 | retval = p->pid; | |
1497 | } else { | |
1498 | retval = wait_noreap_copyout(p, pid, uid, | |
1499 | CLD_CONTINUED, SIGCONT, | |
1500 | infop, ru); | |
1501 | BUG_ON(retval == 0); | |
1502 | } | |
1503 | ||
1504 | return retval; | |
1505 | } | |
1506 | ||
1507 | ||
1508 | static inline int my_ptrace_child(struct task_struct *p) | |
1509 | { | |
1510 | if (!(p->ptrace & PT_PTRACED)) | |
1511 | return 0; | |
1512 | if (!(p->ptrace & PT_ATTACHED)) | |
1513 | return 1; | |
1514 | /* | |
1515 | * This child was PTRACE_ATTACH'd. We should be seeing it only if | |
1516 | * we are the attacher. If we are the real parent, this is a race | |
1517 | * inside ptrace_attach. It is waiting for the tasklist_lock, | |
1518 | * which we have to switch the parent links, but has already set | |
1519 | * the flags in p->ptrace. | |
1520 | */ | |
1521 | return (p->parent != p->real_parent); | |
1522 | } | |
1523 | ||
1524 | static long do_wait(pid_t pid, int options, struct siginfo __user *infop, | |
1525 | int __user *stat_addr, struct rusage __user *ru) | |
1526 | { | |
1527 | DECLARE_WAITQUEUE(wait, current); | |
1528 | struct task_struct *tsk; | |
1529 | int flag, retval; | |
73243284 | 1530 | int allowed, denied; |
1da177e4 LT |
1531 | |
1532 | add_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1533 | repeat: | |
1534 | /* | |
1535 | * We will set this flag if we see any child that might later | |
1536 | * match our criteria, even if we are not able to reap it yet. | |
1537 | */ | |
1538 | flag = 0; | |
73243284 | 1539 | allowed = denied = 0; |
1da177e4 LT |
1540 | current->state = TASK_INTERRUPTIBLE; |
1541 | read_lock(&tasklist_lock); | |
1542 | tsk = current; | |
1543 | do { | |
1544 | struct task_struct *p; | |
1545 | struct list_head *_p; | |
1546 | int ret; | |
1547 | ||
1548 | list_for_each(_p,&tsk->children) { | |
36c8b586 | 1549 | p = list_entry(_p, struct task_struct, sibling); |
1da177e4 LT |
1550 | |
1551 | ret = eligible_child(pid, options, p); | |
1552 | if (!ret) | |
1553 | continue; | |
1554 | ||
73243284 RM |
1555 | if (unlikely(ret < 0)) { |
1556 | denied = ret; | |
1557 | continue; | |
1558 | } | |
1559 | allowed = 1; | |
1560 | ||
1da177e4 LT |
1561 | switch (p->state) { |
1562 | case TASK_TRACED: | |
7f2a5255 RM |
1563 | /* |
1564 | * When we hit the race with PTRACE_ATTACH, | |
1565 | * we will not report this child. But the | |
1566 | * race means it has not yet been moved to | |
1567 | * our ptrace_children list, so we need to | |
1568 | * set the flag here to avoid a spurious ECHILD | |
1569 | * when the race happens with the only child. | |
1570 | */ | |
1571 | flag = 1; | |
1da177e4 LT |
1572 | if (!my_ptrace_child(p)) |
1573 | continue; | |
1574 | /*FALLTHROUGH*/ | |
1575 | case TASK_STOPPED: | |
1576 | /* | |
1577 | * It's stopped now, so it might later | |
1578 | * continue, exit, or stop again. | |
1579 | */ | |
1580 | flag = 1; | |
1581 | if (!(options & WUNTRACED) && | |
1582 | !my_ptrace_child(p)) | |
1583 | continue; | |
1584 | retval = wait_task_stopped(p, ret == 2, | |
1585 | (options & WNOWAIT), | |
1586 | infop, | |
1587 | stat_addr, ru); | |
1588 | if (retval == -EAGAIN) | |
1589 | goto repeat; | |
1590 | if (retval != 0) /* He released the lock. */ | |
1591 | goto end; | |
1592 | break; | |
1593 | default: | |
1594 | // case EXIT_DEAD: | |
1595 | if (p->exit_state == EXIT_DEAD) | |
1596 | continue; | |
1597 | // case EXIT_ZOMBIE: | |
1598 | if (p->exit_state == EXIT_ZOMBIE) { | |
1599 | /* | |
1600 | * Eligible but we cannot release | |
1601 | * it yet: | |
1602 | */ | |
1603 | if (ret == 2) | |
1604 | goto check_continued; | |
1605 | if (!likely(options & WEXITED)) | |
1606 | continue; | |
1607 | retval = wait_task_zombie( | |
1608 | p, (options & WNOWAIT), | |
1609 | infop, stat_addr, ru); | |
1610 | /* He released the lock. */ | |
1611 | if (retval != 0) | |
1612 | goto end; | |
1613 | break; | |
1614 | } | |
1615 | check_continued: | |
1616 | /* | |
1617 | * It's running now, so it might later | |
1618 | * exit, stop, or stop and then continue. | |
1619 | */ | |
1620 | flag = 1; | |
1621 | if (!unlikely(options & WCONTINUED)) | |
1622 | continue; | |
1623 | retval = wait_task_continued( | |
1624 | p, (options & WNOWAIT), | |
1625 | infop, stat_addr, ru); | |
1626 | if (retval != 0) /* He released the lock. */ | |
1627 | goto end; | |
1628 | break; | |
1629 | } | |
1630 | } | |
1631 | if (!flag) { | |
1632 | list_for_each(_p, &tsk->ptrace_children) { | |
1633 | p = list_entry(_p, struct task_struct, | |
1634 | ptrace_list); | |
1635 | if (!eligible_child(pid, options, p)) | |
1636 | continue; | |
1637 | flag = 1; | |
1638 | break; | |
1639 | } | |
1640 | } | |
1641 | if (options & __WNOTHREAD) | |
1642 | break; | |
1643 | tsk = next_thread(tsk); | |
125e1874 | 1644 | BUG_ON(tsk->signal != current->signal); |
1da177e4 LT |
1645 | } while (tsk != current); |
1646 | ||
1647 | read_unlock(&tasklist_lock); | |
1648 | if (flag) { | |
1649 | retval = 0; | |
1650 | if (options & WNOHANG) | |
1651 | goto end; | |
1652 | retval = -ERESTARTSYS; | |
1653 | if (signal_pending(current)) | |
1654 | goto end; | |
1655 | schedule(); | |
1656 | goto repeat; | |
1657 | } | |
1658 | retval = -ECHILD; | |
73243284 RM |
1659 | if (unlikely(denied) && !allowed) |
1660 | retval = denied; | |
1da177e4 LT |
1661 | end: |
1662 | current->state = TASK_RUNNING; | |
1663 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); | |
1664 | if (infop) { | |
1665 | if (retval > 0) | |
1666 | retval = 0; | |
1667 | else { | |
1668 | /* | |
1669 | * For a WNOHANG return, clear out all the fields | |
1670 | * we would set so the user can easily tell the | |
1671 | * difference. | |
1672 | */ | |
1673 | if (!retval) | |
1674 | retval = put_user(0, &infop->si_signo); | |
1675 | if (!retval) | |
1676 | retval = put_user(0, &infop->si_errno); | |
1677 | if (!retval) | |
1678 | retval = put_user(0, &infop->si_code); | |
1679 | if (!retval) | |
1680 | retval = put_user(0, &infop->si_pid); | |
1681 | if (!retval) | |
1682 | retval = put_user(0, &infop->si_uid); | |
1683 | if (!retval) | |
1684 | retval = put_user(0, &infop->si_status); | |
1685 | } | |
1686 | } | |
1687 | return retval; | |
1688 | } | |
1689 | ||
1690 | asmlinkage long sys_waitid(int which, pid_t pid, | |
1691 | struct siginfo __user *infop, int options, | |
1692 | struct rusage __user *ru) | |
1693 | { | |
1694 | long ret; | |
1695 | ||
1696 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) | |
1697 | return -EINVAL; | |
1698 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) | |
1699 | return -EINVAL; | |
1700 | ||
1701 | switch (which) { | |
1702 | case P_ALL: | |
1703 | pid = -1; | |
1704 | break; | |
1705 | case P_PID: | |
1706 | if (pid <= 0) | |
1707 | return -EINVAL; | |
1708 | break; | |
1709 | case P_PGID: | |
1710 | if (pid <= 0) | |
1711 | return -EINVAL; | |
1712 | pid = -pid; | |
1713 | break; | |
1714 | default: | |
1715 | return -EINVAL; | |
1716 | } | |
1717 | ||
1718 | ret = do_wait(pid, options, infop, NULL, ru); | |
1719 | ||
1720 | /* avoid REGPARM breakage on x86: */ | |
1721 | prevent_tail_call(ret); | |
1722 | return ret; | |
1723 | } | |
1724 | ||
1725 | asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr, | |
1726 | int options, struct rusage __user *ru) | |
1727 | { | |
1728 | long ret; | |
1729 | ||
1730 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| | |
1731 | __WNOTHREAD|__WCLONE|__WALL)) | |
1732 | return -EINVAL; | |
1733 | ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru); | |
1734 | ||
1735 | /* avoid REGPARM breakage on x86: */ | |
1736 | prevent_tail_call(ret); | |
1737 | return ret; | |
1738 | } | |
1739 | ||
1740 | #ifdef __ARCH_WANT_SYS_WAITPID | |
1741 | ||
1742 | /* | |
1743 | * sys_waitpid() remains for compatibility. waitpid() should be | |
1744 | * implemented by calling sys_wait4() from libc.a. | |
1745 | */ | |
1746 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) | |
1747 | { | |
1748 | return sys_wait4(pid, stat_addr, options, NULL); | |
1749 | } | |
1750 | ||
1751 | #endif |