| 1 | |
| 2 | * linux/kernel/exit.c
|
| 3 | *
|
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds
|
| 5 |
|
| 6 |
|
| 7 | #include <linux/mm.h>
|
| 8 | #include <linux/slab.h>
|
| 9 | #include <linux/interrupt.h>
|
| 10 | #include <linux/module.h>
|
| 11 | #include <linux/capability.h>
|
| 12 | #include <linux/completion.h>
|
| 13 | #include <linux/personality.h>
|
| 14 | #include <linux/tty.h>
|
| 15 | #include <linux/mnt_namespace.h>
|
| 16 | #include <linux/key.h>
|
| 17 | #include <linux/security.h>
|
| 18 | #include <linux/cpu.h>
|
| 19 | #include <linux/acct.h>
|
| 20 | #include <linux/tsacct_kern.h>
|
| 21 | #include <linux/file.h>
|
| 22 | #include <linux/fdtable.h>
|
| 23 | #include <linux/binfmts.h>
|
| 24 | #include <linux/nsproxy.h>
|
| 25 | #include <linux/pid_namespace.h>
|
| 26 | #include <linux/ptrace.h>
|
| 27 | #include <linux/profile.h>
|
| 28 | #include <linux/mount.h>
|
| 29 | #include <linux/proc_fs.h>
|
| 30 | #include <linux/kthread.h>
|
| 31 | #include <linux/mempolicy.h>
|
| 32 | #include <linux/taskstats_kern.h>
|
| 33 | #include <linux/delayacct.h>
|
| 34 | #include <linux/freezer.h>
|
| 35 | #include <linux/cgroup.h>
|
| 36 | #include <linux/syscalls.h>
|
| 37 | #include <linux/signal.h>
|
| 38 | #include <linux/posix-timers.h>
|
| 39 | #include <linux/cn_proc.h>
|
| 40 | #include <linux/mutex.h>
|
| 41 | #include <linux/futex.h>
|
| 42 | #include <linux/compat.h>
|
| 43 | #include <linux/pipe_fs_i.h>
|
| 44 | #include <linux/audit.h>
|
| 45 | #include <linux/resource.h>
|
| 46 | #include <linux/blkdev.h>
|
| 47 | #include <linux/task_io_accounting_ops.h>
|
| 48 |
|
| 49 | #include <asm/uaccess.h>
|
| 50 | #include <asm/unistd.h>
|
| 51 | #include <asm/pgtable.h>
|
| 52 | #include <asm/mmu_context.h>
|
| 53 |
|
| 54 | static void exit_mm(struct task_struct * tsk);
|
| 55 |
|
| 56 | static inline int task_detached(struct task_struct *p)
|
| 57 | {
|
| 58 | return p->exit_signal == -1;
|
| 59 | }
|
| 60 |
|
| 61 | static void __unhash_process(struct task_struct *p)
|
| 62 | {
|
| 63 | nr_threads--;
|
| 64 | detach_pid(p, PIDTYPE_PID);
|
| 65 | if (thread_group_leader(p)) {
|
| 66 | detach_pid(p, PIDTYPE_PGID);
|
| 67 | detach_pid(p, PIDTYPE_SID);
|
| 68 |
|
| 69 | list_del_rcu(&p->tasks);
|
| 70 | __get_cpu_var(process_counts)--;
|
| 71 | }
|
| 72 | list_del_rcu(&p->thread_group);
|
| 73 | remove_parent(p);
|
| 74 | }
|
| 75 |
|
| 76 | |
| 77 | * This function expects the tasklist_lock write-locked.
|
| 78 |
|
| 79 | static void __exit_signal(struct task_struct *tsk)
|
| 80 | {
|
| 81 | struct signal_struct *sig = tsk->signal;
|
| 82 | struct sighand_struct *sighand;
|
| 83 |
|
| 84 | BUG_ON(!sig);
|
| 85 | BUG_ON(!atomic_read(&sig->count));
|
| 86 |
|
| 87 | rcu_read_lock();
|
| 88 | sighand = rcu_dereference(tsk->sighand);
|
| 89 | spin_lock(&sighand->siglock);
|
| 90 |
|
| 91 | posix_cpu_timers_exit(tsk);
|
| 92 | if (atomic_dec_and_test(&sig->count))
|
| 93 | posix_cpu_timers_exit_group(tsk);
|
| 94 | else {
|
| 95 | |
| 96 | * If there is any task waiting for the group exit
|
| 97 | * then notify it:
|
| 98 |
|
| 99 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count)
|
| 100 | wake_up_process(sig->group_exit_task);
|
| 101 |
|
| 102 | if (tsk == sig->curr_target)
|
| 103 | sig->curr_target = next_thread(tsk);
|
| 104 | |
| 105 | * Accumulate here the counters for all threads but the
|
| 106 | * group leader as they die, so they can be added into
|
| 107 | * the process-wide totals when those are taken.
|
| 108 | * The group leader stays around as a zombie as long
|
| 109 | * as there are other threads. When it gets reaped,
|
| 110 | * the exit.c code will add its counts into these totals.
|
| 111 | * We won't ever get here for the group leader, since it
|
| 112 | * will have been the last reference on the signal_struct.
|
| 113 |
|
| 114 | sig->utime = cputime_add(sig->utime, tsk->utime);
|
| 115 | sig->stime = cputime_add(sig->stime, tsk->stime);
|
| 116 | sig->gtime = cputime_add(sig->gtime, tsk->gtime);
|
| 117 | sig->min_flt += tsk->min_flt;
|
| 118 | sig->maj_flt += tsk->maj_flt;
|
| 119 | sig->nvcsw += tsk->nvcsw;
|
| 120 | sig->nivcsw += tsk->nivcsw;
|
| 121 | sig->inblock += task_io_get_inblock(tsk);
|
| 122 | sig->oublock += task_io_get_oublock(tsk);
|
| 123 | sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
|
| 124 | sig = NULL;
|
| 125 | }
|
| 126 |
|
| 127 | __unhash_process(tsk);
|
| 128 |
|
| 129 | |
| 130 | * Do this under ->siglock, we can race with another thread
|
| 131 | * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
|
| 132 |
|
| 133 | flush_sigqueue(&tsk->pending);
|
| 134 |
|
| 135 | tsk->signal = NULL;
|
| 136 | tsk->sighand = NULL;
|
| 137 | spin_unlock(&sighand->siglock);
|
| 138 | rcu_read_unlock();
|
| 139 |
|
| 140 | __cleanup_sighand(sighand);
|
| 141 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
|
| 142 | if (sig) {
|
| 143 | flush_sigqueue(&sig->shared_pending);
|
| 144 | taskstats_tgid_free(sig);
|
| 145 | __cleanup_signal(sig);
|
| 146 | }
|
| 147 | }
|
| 148 |
|
| 149 | static void delayed_put_task_struct(struct rcu_head *rhp)
|
| 150 | {
|
| 151 | put_task_struct(container_of(rhp, struct task_struct, rcu));
|
| 152 | }
|
| 153 |
|
| 154 | void release_task(struct task_struct * p)
|
| 155 | {
|
| 156 | struct task_struct *leader;
|
| 157 | int zap_leader;
|
| 158 | repeat:
|
| 159 | atomic_dec(&p->user->processes);
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| 160 | proc_flush_task(p);
|
| 161 | write_lock_irq(&tasklist_lock);
|
| 162 | ptrace_unlink(p);
|
| 163 | BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
|
| 164 | __exit_signal(p);
|
| 165 |
|
| 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(task_detached(leader));
|
| 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 = task_detached(leader);
|
| 185 | }
|
| 186 |
|
| 187 | write_unlock_irq(&tasklist_lock);
|
| 188 | release_thread(p);
|
| 189 | call_rcu(&p->rcu, delayed_put_task_struct);
|
| 190 |
|
| 191 | p = leader;
|
| 192 | if (unlikely(zap_leader))
|
| 193 | goto repeat;
|
| 194 | }
|
| 195 |
|
| 196 | |
| 197 | * This checks not only the pgrp, but falls back on the pid if no
|
| 198 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
|
| 199 | * without this...
|
| 200 | *
|
| 201 | * The caller must hold rcu lock or the tasklist lock.
|
| 202 |
|
| 203 | struct pid *session_of_pgrp(struct pid *pgrp)
|
| 204 | {
|
| 205 | struct task_struct *p;
|
| 206 | struct pid *sid = NULL;
|
| 207 |
|
| 208 | p = pid_task(pgrp, PIDTYPE_PGID);
|
| 209 | if (p == NULL)
|
| 210 | p = pid_task(pgrp, PIDTYPE_PID);
|
| 211 | if (p != NULL)
|
| 212 | sid = task_session(p);
|
| 213 |
|
| 214 | return sid;
|
| 215 | }
|
| 216 |
|
| 217 | |
| 218 | * Determine if a process group is "orphaned", according to the POSIX
|
| 219 | * definition in 2.2.2.52. Orphaned process groups are not to be affected
|
| 220 | * by terminal-generated stop signals. Newly orphaned process groups are
|
| 221 | * to receive a SIGHUP and a SIGCONT.
|
| 222 | *
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| 223 | * "I ask you, have you ever known what it is to be an orphan?"
|
| 224 |
|
| 225 | static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task)
|
| 226 | {
|
| 227 | struct task_struct *p;
|
| 228 |
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| 229 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
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| 230 | if ((p == ignored_task) ||
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| 231 | (p->exit_state && thread_group_empty(p)) ||
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| 232 | is_global_init(p->real_parent))
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| 233 | continue;
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| 234 |
|
| 235 | if (task_pgrp(p->real_parent) != pgrp &&
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| 236 | task_session(p->real_parent) == task_session(p))
|
| 237 | return 0;
|
| 238 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
|
| 239 |
|
| 240 | return 1;
|
| 241 | }
|
| 242 |
|
| 243 | int is_current_pgrp_orphaned(void)
|
| 244 | {
|
| 245 | int retval;
|
| 246 |
|
| 247 | read_lock(&tasklist_lock);
|
| 248 | retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
|
| 249 | read_unlock(&tasklist_lock);
|
| 250 |
|
| 251 | return retval;
|
| 252 | }
|
| 253 |
|
| 254 | static int has_stopped_jobs(struct pid *pgrp)
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| 255 | {
|
| 256 | int retval = 0;
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| 257 | struct task_struct *p;
|
| 258 |
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| 259 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
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| 260 | if (!task_is_stopped(p))
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| 261 | continue;
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| 262 | retval = 1;
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| 263 | break;
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| 264 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
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| 265 | return retval;
|
| 266 | }
|
| 267 |
|
| 268 | |
| 269 | * Check to see if any process groups have become orphaned as
|
| 270 | * a result of our exiting, and if they have any stopped jobs,
|
| 271 | * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
|
| 272 |
|
| 273 | static void
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| 274 | kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
|
| 275 | {
|
| 276 | struct pid *pgrp = task_pgrp(tsk);
|
| 277 | struct task_struct *ignored_task = tsk;
|
| 278 |
|
| 279 | if (!parent)
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| 280 | |
| 281 | * we are and we were the only connection outside.
|
| 282 |
|
| 283 | parent = tsk->real_parent;
|
| 284 | else
|
| 285 | |
| 286 | * we are, and it was the only connection outside.
|
| 287 |
|
| 288 | ignored_task = NULL;
|
| 289 |
|
| 290 | if (task_pgrp(parent) != pgrp &&
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| 291 | task_session(parent) == task_session(tsk) &&
|
| 292 | will_become_orphaned_pgrp(pgrp, ignored_task) &&
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| 293 | has_stopped_jobs(pgrp)) {
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| 294 | __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
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| 295 | __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
|
| 296 | }
|
| 297 | }
|
| 298 |
|
| 299 | |
| 300 | * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
|
| 301 | *
|
| 302 | * If a kernel thread is launched as a result of a system call, or if
|
| 303 | * it ever exits, it should generally reparent itself to kthreadd so it
|
| 304 | * isn't in the way of other processes and is correctly cleaned up on exit.
|
| 305 | *
|
| 306 | * The various task state such as scheduling policy and priority may have
|
| 307 | * been inherited from a user process, so we reset them to sane values here.
|
| 308 | *
|
| 309 | * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
|
| 310 |
|
| 311 | static void reparent_to_kthreadd(void)
|
| 312 | {
|
| 313 | write_lock_irq(&tasklist_lock);
|
| 314 |
|
| 315 | ptrace_unlink(current);
|
| 316 |
|
| 317 | remove_parent(current);
|
| 318 | current->real_parent = current->parent = kthreadd_task;
|
| 319 | add_parent(current);
|
| 320 |
|
| 321 |
|
| 322 | current->exit_signal = SIGCHLD;
|
| 323 |
|
| 324 | if (task_nice(current) < 0)
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| 325 | set_user_nice(current, 0);
|
| 326 |
|
| 327 |
|
| 328 |
|
| 329 | security_task_reparent_to_init(current);
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| 330 | memcpy(current->signal->rlim, init_task.signal->rlim,
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| 331 | sizeof(current->signal->rlim));
|
| 332 | atomic_inc(&(INIT_USER->__count));
|
| 333 | write_unlock_irq(&tasklist_lock);
|
| 334 | switch_uid(INIT_USER);
|
| 335 | }
|
| 336 |
|
| 337 | void __set_special_pids(struct pid *pid)
|
| 338 | {
|
| 339 | struct task_struct *curr = current->group_leader;
|
| 340 | pid_t nr = pid_nr(pid);
|
| 341 |
|
| 342 | if (task_session(curr) != pid) {
|
| 343 | change_pid(curr, PIDTYPE_SID, pid);
|
| 344 | set_task_session(curr, nr);
|
| 345 | }
|
| 346 | if (task_pgrp(curr) != pid) {
|
| 347 | change_pid(curr, PIDTYPE_PGID, pid);
|
| 348 | set_task_pgrp(curr, nr);
|
| 349 | }
|
| 350 | }
|
| 351 |
|
| 352 | static void set_special_pids(struct pid *pid)
|
| 353 | {
|
| 354 | write_lock_irq(&tasklist_lock);
|
| 355 | __set_special_pids(pid);
|
| 356 | write_unlock_irq(&tasklist_lock);
|
| 357 | }
|
| 358 |
|
| 359 | |
| 360 | * Let kernel threads use this to say that they
|
| 361 | * allow a certain signal (since daemonize() will
|
| 362 | * have disabled all of them by default).
|
| 363 |
|
| 364 | int allow_signal(int sig)
|
| 365 | {
|
| 366 | if (!valid_signal(sig) || sig < 1)
|
| 367 | return -EINVAL;
|
| 368 |
|
| 369 | spin_lock_irq(¤t->sighand->siglock);
|
| 370 | sigdelset(¤t->blocked, sig);
|
| 371 | if (!current->mm) {
|
| 372 | |
| 373 | Let the signal code know it'll be handled, so
|
| 374 | that they don't get converted to SIGKILL or
|
| 375 | just silently dropped
|
| 376 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
|
| 377 | }
|
| 378 | recalc_sigpending();
|
| 379 | spin_unlock_irq(¤t->sighand->siglock);
|
| 380 | return 0;
|
| 381 | }
|
| 382 |
|
| 383 | EXPORT_SYMBOL(allow_signal);
|
| 384 |
|
| 385 | int disallow_signal(int sig)
|
| 386 | {
|
| 387 | if (!valid_signal(sig) || sig < 1)
|
| 388 | return -EINVAL;
|
| 389 |
|
| 390 | spin_lock_irq(¤t->sighand->siglock);
|
| 391 | current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;
|
| 392 | recalc_sigpending();
|
| 393 | spin_unlock_irq(¤t->sighand->siglock);
|
| 394 | return 0;
|
| 395 | }
|
| 396 |
|
| 397 | EXPORT_SYMBOL(disallow_signal);
|
| 398 |
|
| 399 | |
| 400 | * Put all the gunge required to become a kernel thread without
|
| 401 | * attached user resources in one place where it belongs.
|
| 402 |
|
| 403 |
|
| 404 | void daemonize(const char *name, ...)
|
| 405 | {
|
| 406 | va_list args;
|
| 407 | struct fs_struct *fs;
|
| 408 | sigset_t blocked;
|
| 409 |
|
| 410 | va_start(args, name);
|
| 411 | vsnprintf(current->comm, sizeof(current->comm), name, args);
|
| 412 | va_end(args);
|
| 413 |
|
| 414 | |
| 415 | * If we were started as result of loading a module, close all of the
|
| 416 | * user space pages. We don't need them, and if we didn't close them
|
| 417 | * they would be locked into memory.
|
| 418 |
|
| 419 | exit_mm(current);
|
| 420 | |
| 421 | * We don't want to have TIF_FREEZE set if the system-wide hibernation
|
| 422 | * or suspend transition begins right now.
|
| 423 |
|
| 424 | current->flags |= PF_NOFREEZE;
|
| 425 |
|
| 426 | if (current->nsproxy != &init_nsproxy) {
|
| 427 | get_nsproxy(&init_nsproxy);
|
| 428 | switch_task_namespaces(current, &init_nsproxy);
|
| 429 | }
|
| 430 | set_special_pids(&init_struct_pid);
|
| 431 | proc_clear_tty(current);
|
| 432 |
|
| 433 |
|
| 434 | sigfillset(&blocked);
|
| 435 | sigprocmask(SIG_BLOCK, &blocked, NULL);
|
| 436 | flush_signals(current);
|
| 437 |
|
| 438 |
|
| 439 |
|
| 440 | exit_fs(current);
|
| 441 | fs = init_task.fs;
|
| 442 | current->fs = fs;
|
| 443 | atomic_inc(&fs->count);
|
| 444 |
|
| 445 | exit_files(current);
|
| 446 | current->files = init_task.files;
|
| 447 | atomic_inc(¤t->files->count);
|
| 448 |
|
| 449 | reparent_to_kthreadd();
|
| 450 | }
|
| 451 |
|
| 452 | EXPORT_SYMBOL(daemonize);
|
| 453 |
|
| 454 | static void close_files(struct files_struct * files)
|
| 455 | {
|
| 456 | int i, j;
|
| 457 | struct fdtable *fdt;
|
| 458 |
|
| 459 | j = 0;
|
| 460 |
|
| 461 | |
| 462 | * It is safe to dereference the fd table without RCU or
|
| 463 | * ->file_lock because this is the last reference to the
|
| 464 | * files structure.
|
| 465 |
|
| 466 | fdt = files_fdtable(files);
|
| 467 | for (;;) {
|
| 468 | unsigned long set;
|
| 469 | i = j * __NFDBITS;
|
| 470 | if (i >= fdt->max_fds)
|
| 471 | break;
|
| 472 | set = fdt->open_fds->fds_bits[j++];
|
| 473 | while (set) {
|
| 474 | if (set & 1) {
|
| 475 | struct file * file = xchg(&fdt->fd[i], NULL);
|
| 476 | if (file) {
|
| 477 | filp_close(file, files);
|
| 478 | cond_resched();
|
| 479 | }
|
| 480 | }
|
| 481 | i++;
|
| 482 | set >>= 1;
|
| 483 | }
|
| 484 | }
|
| 485 | }
|
| 486 |
|
| 487 | struct files_struct *get_files_struct(struct task_struct *task)
|
| 488 | {
|
| 489 | struct files_struct *files;
|
| 490 |
|
| 491 | task_lock(task);
|
| 492 | files = task->files;
|
| 493 | if (files)
|
| 494 | atomic_inc(&files->count);
|
| 495 | task_unlock(task);
|
| 496 |
|
| 497 | return files;
|
| 498 | }
|
| 499 |
|
| 500 | void put_files_struct(struct files_struct *files)
|
| 501 | {
|
| 502 | struct fdtable *fdt;
|
| 503 |
|
| 504 | if (atomic_dec_and_test(&files->count)) {
|
| 505 | close_files(files);
|
| 506 | |
| 507 | * Free the fd and fdset arrays if we expanded them.
|
| 508 | * If the fdtable was embedded, pass files for freeing
|
| 509 | * at the end of the RCU grace period. Otherwise,
|
| 510 | * you can free files immediately.
|
| 511 |
|
| 512 | fdt = files_fdtable(files);
|
| 513 | if (fdt != &files->fdtab)
|
| 514 | kmem_cache_free(files_cachep, files);
|
| 515 | free_fdtable(fdt);
|
| 516 | }
|
| 517 | }
|
| 518 |
|
| 519 | void reset_files_struct(struct files_struct *files)
|
| 520 | {
|
| 521 | struct task_struct *tsk = current;
|
| 522 | struct files_struct *old;
|
| 523 |
|
| 524 | old = tsk->files;
|
| 525 | task_lock(tsk);
|
| 526 | tsk->files = files;
|
| 527 | task_unlock(tsk);
|
| 528 | put_files_struct(old);
|
| 529 | }
|
| 530 |
|
| 531 | void exit_files(struct task_struct *tsk)
|
| 532 | {
|
| 533 | struct files_struct * files = tsk->files;
|
| 534 |
|
| 535 | if (files) {
|
| 536 | task_lock(tsk);
|
| 537 | tsk->files = NULL;
|
| 538 | task_unlock(tsk);
|
| 539 | put_files_struct(files);
|
| 540 | }
|
| 541 | }
|
| 542 |
|
| 543 | void put_fs_struct(struct fs_struct *fs)
|
| 544 | {
|
| 545 |
|
| 546 | if (atomic_dec_and_test(&fs->count)) {
|
| 547 | path_put(&fs->root);
|
| 548 | path_put(&fs->pwd);
|
| 549 | if (fs->altroot.dentry)
|
| 550 | path_put(&fs->altroot);
|
| 551 | kmem_cache_free(fs_cachep, fs);
|
| 552 | }
|
| 553 | }
|
| 554 |
|
| 555 | void exit_fs(struct task_struct *tsk)
|
| 556 | {
|
| 557 | struct fs_struct * fs = tsk->fs;
|
| 558 |
|
| 559 | if (fs) {
|
| 560 | task_lock(tsk);
|
| 561 | tsk->fs = NULL;
|
| 562 | task_unlock(tsk);
|
| 563 | put_fs_struct(fs);
|
| 564 | }
|
| 565 | }
|
| 566 |
|
| 567 | EXPORT_SYMBOL_GPL(exit_fs);
|
| 568 |
|
| 569 | #ifdef CONFIG_MM_OWNER
|
| 570 | |
| 571 | * Task p is exiting and it owned mm, lets find a new owner for it
|
| 572 |
|
| 573 | static inline int
|
| 574 | mm_need_new_owner(struct mm_struct *mm, struct task_struct *p)
|
| 575 | {
|
| 576 | |
| 577 | * If there are other users of the mm and the owner (us) is exiting
|
| 578 | * we need to find a new owner to take on the responsibility.
|
| 579 |
|
| 580 | if (!mm)
|
| 581 | return 0;
|
| 582 | if (atomic_read(&mm->mm_users) <= 1)
|
| 583 | return 0;
|
| 584 | if (mm->owner != p)
|
| 585 | return 0;
|
| 586 | return 1;
|
| 587 | }
|
| 588 |
|
| 589 | void mm_update_next_owner(struct mm_struct *mm)
|
| 590 | {
|
| 591 | struct task_struct *c, *g, *p = current;
|
| 592 |
|
| 593 | retry:
|
| 594 | if (!mm_need_new_owner(mm, p))
|
| 595 | return;
|
| 596 |
|
| 597 | read_lock(&tasklist_lock);
|
| 598 | |
| 599 | * Search in the children
|
| 600 |
|
| 601 | list_for_each_entry(c, &p->children, sibling) {
|
| 602 | if (c->mm == mm)
|
| 603 | goto assign_new_owner;
|
| 604 | }
|
| 605 |
|
| 606 | |
| 607 | * Search in the siblings
|
| 608 |
|
| 609 | list_for_each_entry(c, &p->parent->children, sibling) {
|
| 610 | if (c->mm == mm)
|
| 611 | goto assign_new_owner;
|
| 612 | }
|
| 613 |
|
| 614 | |
| 615 | * Search through everything else. We should not get
|
| 616 | * here often
|
| 617 |
|
| 618 | do_each_thread(g, c) {
|
| 619 | if (c->mm == mm)
|
| 620 | goto assign_new_owner;
|
| 621 | } while_each_thread(g, c);
|
| 622 |
|
| 623 | read_unlock(&tasklist_lock);
|
| 624 | return;
|
| 625 |
|
| 626 | assign_new_owner:
|
| 627 | BUG_ON(c == p);
|
| 628 | get_task_struct(c);
|
| 629 | |
| 630 | * The task_lock protects c->mm from changing.
|
| 631 | * We always want mm->owner->mm == mm
|
| 632 |
|
| 633 | task_lock(c);
|
| 634 | |
| 635 | * Delay read_unlock() till we have the task_lock()
|
| 636 | * to ensure that c does not slip away underneath us
|
| 637 |
|
| 638 | read_unlock(&tasklist_lock);
|
| 639 | if (c->mm != mm) {
|
| 640 | task_unlock(c);
|
| 641 | put_task_struct(c);
|
| 642 | goto retry;
|
| 643 | }
|
| 644 | cgroup_mm_owner_callbacks(mm->owner, c);
|
| 645 | mm->owner = c;
|
| 646 | task_unlock(c);
|
| 647 | put_task_struct(c);
|
| 648 | }
|
| 649 | #endif
|
| 650 |
|
| 651 | |
| 652 | * Turn us into a lazy TLB process if we
|
| 653 | * aren't already..
|
| 654 |
|
| 655 | static void exit_mm(struct task_struct * tsk)
|
| 656 | {
|
| 657 | struct mm_struct *mm = tsk->mm;
|
| 658 |
|
| 659 | mm_release(tsk, mm);
|
| 660 | if (!mm)
|
| 661 | return;
|
| 662 | |
| 663 | * Serialize with any possible pending coredump.
|
| 664 | * We must hold mmap_sem around checking core_waiters
|
| 665 | * and clearing tsk->mm. The core-inducing thread
|
| 666 | * will increment core_waiters for each thread in the
|
| 667 | * group with ->mm != NULL.
|
| 668 |
|
| 669 | down_read(&mm->mmap_sem);
|
| 670 | if (mm->core_waiters) {
|
| 671 | up_read(&mm->mmap_sem);
|
| 672 | down_write(&mm->mmap_sem);
|
| 673 | if (!--mm->core_waiters)
|
| 674 | complete(mm->core_startup_done);
|
| 675 | up_write(&mm->mmap_sem);
|
| 676 |
|
| 677 | wait_for_completion(&mm->core_done);
|
| 678 | down_read(&mm->mmap_sem);
|
| 679 | }
|
| 680 | atomic_inc(&mm->mm_count);
|
| 681 | BUG_ON(mm != tsk->active_mm);
|
| 682 |
|
| 683 | task_lock(tsk);
|
| 684 | tsk->mm = NULL;
|
| 685 | up_read(&mm->mmap_sem);
|
| 686 | enter_lazy_tlb(mm, current);
|
| 687 |
|
| 688 | clear_freeze_flag(tsk);
|
| 689 | task_unlock(tsk);
|
| 690 | mm_update_next_owner(mm);
|
| 691 | mmput(mm);
|
| 692 | }
|
| 693 |
|
| 694 | static void
|
| 695 | reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
|
| 696 | {
|
| 697 | if (p->pdeath_signal)
|
| 698 |
|
| 699 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
|
| 700 |
|
| 701 |
|
| 702 | if (unlikely(traced)) {
|
| 703 |
|
| 704 | list_del_init(&p->ptrace_list);
|
| 705 | if (ptrace_reparented(p))
|
| 706 | list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
|
| 707 | } else {
|
| 708 | |
| 709 | * anyway, so let go of it.
|
| 710 |
|
| 711 | p->ptrace = 0;
|
| 712 | remove_parent(p);
|
| 713 | p->parent = p->real_parent;
|
| 714 | add_parent(p);
|
| 715 |
|
| 716 | if (task_is_traced(p)) {
|
| 717 | |
| 718 | * If it was at a trace stop, turn it into
|
| 719 | * a normal stop since it's no longer being
|
| 720 | * traced.
|
| 721 |
|
| 722 | ptrace_untrace(p);
|
| 723 | }
|
| 724 | }
|
| 725 |
|
| 726 | |
| 727 | * notify anyone anything has happened.
|
| 728 |
|
| 729 | if (same_thread_group(p->real_parent, father))
|
| 730 | return;
|
| 731 |
|
| 732 |
|
| 733 | if (!task_detached(p))
|
| 734 | p->exit_signal = SIGCHLD;
|
| 735 |
|
| 736 | |
| 737 | * also notify the new parent.
|
| 738 |
|
| 739 | if (!traced && p->exit_state == EXIT_ZOMBIE &&
|
| 740 | !task_detached(p) && thread_group_empty(p))
|
| 741 | do_notify_parent(p, p->exit_signal);
|
| 742 |
|
| 743 | kill_orphaned_pgrp(p, father);
|
| 744 | }
|
| 745 |
|
| 746 | |
| 747 | * When we die, we re-parent all our children.
|
| 748 | * Try to give them to another thread in our thread
|
| 749 | * group, and if no such member exists, give it to
|
| 750 | * the child reaper process (ie "init") in our pid
|
| 751 | * space.
|
| 752 |
|
| 753 | static void forget_original_parent(struct task_struct *father)
|
| 754 | {
|
| 755 | struct task_struct *p, *n, *reaper = father;
|
| 756 | struct list_head ptrace_dead;
|
| 757 |
|
| 758 | INIT_LIST_HEAD(&ptrace_dead);
|
| 759 |
|
| 760 | write_lock_irq(&tasklist_lock);
|
| 761 |
|
| 762 | do {
|
| 763 | reaper = next_thread(reaper);
|
| 764 | if (reaper == father) {
|
| 765 | reaper = task_child_reaper(father);
|
| 766 | break;
|
| 767 | }
|
| 768 | } while (reaper->flags & PF_EXITING);
|
| 769 |
|
| 770 | |
| 771 | * There are only two places where our children can be:
|
| 772 | *
|
| 773 | * - in our child list
|
| 774 | * - in our ptraced child list
|
| 775 | *
|
| 776 | * Search them and reparent children.
|
| 777 |
|
| 778 | list_for_each_entry_safe(p, n, &father->children, sibling) {
|
| 779 | int ptrace;
|
| 780 |
|
| 781 | ptrace = p->ptrace;
|
| 782 |
|
| 783 |
|
| 784 | BUG_ON(father != p->real_parent && !ptrace);
|
| 785 |
|
| 786 | if (father == p->real_parent) {
|
| 787 |
|
| 788 | p->real_parent = reaper;
|
| 789 | reparent_thread(p, father, 0);
|
| 790 | } else {
|
| 791 |
|
| 792 | __ptrace_unlink (p);
|
| 793 | if (p->exit_state == EXIT_ZOMBIE && !task_detached(p) &&
|
| 794 | thread_group_empty(p))
|
| 795 | do_notify_parent(p, p->exit_signal);
|
| 796 | }
|
| 797 |
|
| 798 | |
| 799 | * if the ptraced child is a detached zombie we must collect
|
| 800 | * it before we exit, or it will remain zombie forever since
|
| 801 | * we prevented it from self-reap itself while it was being
|
| 802 | * traced by us, to be able to see it in wait4.
|
| 803 |
|
| 804 | if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && task_detached(p)))
|
| 805 | list_add(&p->ptrace_list, &ptrace_dead);
|
| 806 | }
|
| 807 |
|
| 808 | list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) {
|
| 809 | p->real_parent = reaper;
|
| 810 | reparent_thread(p, father, 1);
|
| 811 | }
|
| 812 |
|
| 813 | write_unlock_irq(&tasklist_lock);
|
| 814 | BUG_ON(!list_empty(&father->children));
|
| 815 | BUG_ON(!list_empty(&father->ptrace_children));
|
| 816 |
|
| 817 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_list) {
|
| 818 | list_del_init(&p->ptrace_list);
|
| 819 | release_task(p);
|
| 820 | }
|
| 821 |
|
| 822 | }
|
| 823 |
|
| 824 | |
| 825 | * Send signals to all our closest relatives so that they know
|
| 826 | * to properly mourn us..
|
| 827 |
|
| 828 | static void exit_notify(struct task_struct *tsk, int group_dead)
|
| 829 | {
|
| 830 | int state;
|
| 831 |
|
| 832 | |
| 833 | * This does two things:
|
| 834 | *
|
| 835 | * A. Make init inherit all the child processes
|
| 836 | * B. Check to see if any process groups have become orphaned
|
| 837 | * as a result of our exiting, and if they have any stopped
|
| 838 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
|
| 839 |
|
| 840 | forget_original_parent(tsk);
|
| 841 | exit_task_namespaces(tsk);
|
| 842 |
|
| 843 | write_lock_irq(&tasklist_lock);
|
| 844 | if (group_dead)
|
| 845 | kill_orphaned_pgrp(tsk->group_leader, NULL);
|
| 846 |
|
| 847 | |
| 848 | *
|
| 849 | * Thread signals are configurable, but you aren't going to use
|
| 850 | * that to send signals to arbitary processes.
|
| 851 | * That stops right now.
|
| 852 | *
|
| 853 | * If the parent exec id doesn't match the exec id we saved
|
| 854 | * when we started then we know the parent has changed security
|
| 855 | * domain.
|
| 856 | *
|
| 857 | * If our self_exec id doesn't match our parent_exec_id then
|
| 858 | * we have changed execution domain as these two values started
|
| 859 | * the same after a fork.
|
| 860 |
|
| 861 | if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
|
| 862 | (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
|
| 863 | tsk->self_exec_id != tsk->parent_exec_id) &&
|
| 864 | !capable(CAP_KILL))
|
| 865 | tsk->exit_signal = SIGCHLD;
|
| 866 |
|
| 867 | |
| 868 | * send it a SIGCHLD instead of honoring exit_signal. exit_signal
|
| 869 | * only has special meaning to our real parent.
|
| 870 |
|
| 871 | if (!task_detached(tsk) && thread_group_empty(tsk)) {
|
| 872 | int signal = ptrace_reparented(tsk) ?
|
| 873 | SIGCHLD : tsk->exit_signal;
|
| 874 | do_notify_parent(tsk, signal);
|
| 875 | } else if (tsk->ptrace) {
|
| 876 | do_notify_parent(tsk, SIGCHLD);
|
| 877 | }
|
| 878 |
|
| 879 | state = EXIT_ZOMBIE;
|
| 880 | if (task_detached(tsk) && likely(!tsk->ptrace))
|
| 881 | state = EXIT_DEAD;
|
| 882 | tsk->exit_state = state;
|
| 883 |
|
| 884 |
|
| 885 | if (thread_group_leader(tsk) &&
|
| 886 | tsk->signal->notify_count < 0 &&
|
| 887 | tsk->signal->group_exit_task)
|
| 888 | wake_up_process(tsk->signal->group_exit_task);
|
| 889 |
|
| 890 | write_unlock_irq(&tasklist_lock);
|
| 891 |
|
| 892 |
|
| 893 | if (state == EXIT_DEAD)
|
| 894 | release_task(tsk);
|
| 895 | }
|
| 896 |
|
| 897 | #ifdef CONFIG_DEBUG_STACK_USAGE
|
| 898 | static void check_stack_usage(void)
|
| 899 | {
|
| 900 | static DEFINE_SPINLOCK(low_water_lock);
|
| 901 | static int lowest_to_date = THREAD_SIZE;
|
| 902 | unsigned long *n = end_of_stack(current);
|
| 903 | unsigned long free;
|
| 904 |
|
| 905 | while (*n == 0)
|
| 906 | n++;
|
| 907 | free = (unsigned long)n - (unsigned long)end_of_stack(current);
|
| 908 |
|
| 909 | if (free >= lowest_to_date)
|
| 910 | return;
|
| 911 |
|
| 912 | spin_lock(&low_water_lock);
|
| 913 | if (free < lowest_to_date) {
|
| 914 | printk(KERN_WARNING "%s used greatest stack depth: %lu bytes "
|
| 915 | "left\n",
|
| 916 | current->comm, free);
|
| 917 | lowest_to_date = free;
|
| 918 | }
|
| 919 | spin_unlock(&low_water_lock);
|
| 920 | }
|
| 921 | #else
|
| 922 | static inline void check_stack_usage(void) {}
|
| 923 | #endif
|
| 924 |
|
| 925 | static inline void exit_child_reaper(struct task_struct *tsk)
|
| 926 | {
|
| 927 | if (likely(tsk->group_leader != task_child_reaper(tsk)))
|
| 928 | return;
|
| 929 |
|
| 930 | if (tsk->nsproxy->pid_ns == &init_pid_ns)
|
| 931 | panic("Attempted to kill init!");
|
| 932 |
|
| 933 | |
| 934 | * @tsk is the last thread in the 'cgroup-init' and is exiting.
|
| 935 | * Terminate all remaining processes in the namespace and reap them
|
| 936 | * before exiting @tsk.
|
| 937 | *
|
| 938 | * Note that @tsk (last thread of cgroup-init) may not necessarily
|
| 939 | * be the child-reaper (i.e main thread of cgroup-init) of the
|
| 940 | * namespace i.e the child_reaper may have already exited.
|
| 941 | *
|
| 942 | * Even after a child_reaper exits, we let it inherit orphaned children,
|
| 943 | * because, pid_ns->child_reaper remains valid as long as there is
|
| 944 | * at least one living sub-thread in the cgroup init.
|
| 945 |
|
| 946 | * This living sub-thread of the cgroup-init will be notified when
|
| 947 | * a child inherited by the 'child-reaper' exits (do_notify_parent()
|
| 948 | * uses __group_send_sig_info()). Further, when reaping child processes,
|
| 949 | * do_wait() iterates over children of all living sub threads.
|
| 950 |
|
| 951 | * i.e even though 'child_reaper' thread is listed as the parent of the
|
| 952 | * orphaned children, any living sub-thread in the cgroup-init can
|
| 953 | * perform the role of the child_reaper.
|
| 954 |
|
| 955 | zap_pid_ns_processes(tsk->nsproxy->pid_ns);
|
| 956 | }
|
| 957 |
|
| 958 | NORET_TYPE void do_exit(long code)
|
| 959 | {
|
| 960 | struct task_struct *tsk = current;
|
| 961 | int group_dead;
|
| 962 |
|
| 963 | profile_task_exit(tsk);
|
| 964 |
|
| 965 | WARN_ON(atomic_read(&tsk->fs_excl));
|
| 966 |
|
| 967 | if (unlikely(in_interrupt()))
|
| 968 | panic("Aiee, killing interrupt handler!");
|
| 969 | if (unlikely(!tsk->pid))
|
| 970 | panic("Attempted to kill the idle task!");
|
| 971 |
|
| 972 | if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
|
| 973 | current->ptrace_message = code;
|
| 974 | ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
|
| 975 | }
|
| 976 |
|
| 977 | |
| 978 | * We're taking recursive faults here in do_exit. Safest is to just
|
| 979 | * leave this task alone and wait for reboot.
|
| 980 |
|
| 981 | if (unlikely(tsk->flags & PF_EXITING)) {
|
| 982 | printk(KERN_ALERT
|
| 983 | "Fixing recursive fault but reboot is needed!\n");
|
| 984 | |
| 985 | * We can do this unlocked here. The futex code uses
|
| 986 | * this flag just to verify whether the pi state
|
| 987 | * cleanup has been done or not. In the worst case it
|
| 988 | * loops once more. We pretend that the cleanup was
|
| 989 | * done as there is no way to return. Either the
|
| 990 | * OWNER_DIED bit is set by now or we push the blocked
|
| 991 | * task into the wait for ever nirwana as well.
|
| 992 |
|
| 993 | tsk->flags |= PF_EXITPIDONE;
|
| 994 | if (tsk->io_context)
|
| 995 | exit_io_context();
|
| 996 | set_current_state(TASK_UNINTERRUPTIBLE);
|
| 997 | schedule();
|
| 998 | }
|
| 999 |
|
| 1000 | exit_signals(tsk);
|
| 1001 | |
| 1002 | * tsk->flags are checked in the futex code to protect against
|
| 1003 | * an exiting task cleaning up the robust pi futexes.
|
| 1004 |
|
| 1005 | smp_mb();
|
| 1006 | spin_unlock_wait(&tsk->pi_lock);
|
| 1007 |
|
| 1008 | if (unlikely(in_atomic()))
|
| 1009 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
|
| 1010 | current->comm, task_pid_nr(current),
|
| 1011 | preempt_count());
|
| 1012 |
|
| 1013 | acct_update_integrals(tsk);
|
| 1014 | if (tsk->mm) {
|
| 1015 | update_hiwater_rss(tsk->mm);
|
| 1016 | update_hiwater_vm(tsk->mm);
|
| 1017 | }
|
| 1018 | group_dead = atomic_dec_and_test(&tsk->signal->live);
|
| 1019 | if (group_dead) {
|
| 1020 | exit_child_reaper(tsk);
|
| 1021 | hrtimer_cancel(&tsk->signal->real_timer);
|
| 1022 | exit_itimers(tsk->signal);
|
| 1023 | }
|
| 1024 | acct_collect(code, group_dead);
|
| 1025 | #ifdef CONFIG_FUTEX
|
| 1026 | if (unlikely(tsk->robust_list))
|
| 1027 | exit_robust_list(tsk);
|
| 1028 | #ifdef CONFIG_COMPAT
|
| 1029 | if (unlikely(tsk->compat_robust_list))
|
| 1030 | compat_exit_robust_list(tsk);
|
| 1031 | #endif
|
| 1032 | #endif
|
| 1033 | if (group_dead)
|
| 1034 | tty_audit_exit();
|
| 1035 | if (unlikely(tsk->audit_context))
|
| 1036 | audit_free(tsk);
|
| 1037 |
|
| 1038 | tsk->exit_code = code;
|
| 1039 | taskstats_exit(tsk, group_dead);
|
| 1040 |
|
| 1041 | exit_mm(tsk);
|
| 1042 |
|
| 1043 | if (group_dead)
|
| 1044 | acct_process();
|
| 1045 | exit_sem(tsk);
|
| 1046 | exit_files(tsk);
|
| 1047 | exit_fs(tsk);
|
| 1048 | check_stack_usage();
|
| 1049 | exit_thread();
|
| 1050 | cgroup_exit(tsk, 1);
|
| 1051 | exit_keys(tsk);
|
| 1052 |
|
| 1053 | if (group_dead && tsk->signal->leader)
|
| 1054 | disassociate_ctty(1);
|
| 1055 |
|
| 1056 | module_put(task_thread_info(tsk)->exec_domain->module);
|
| 1057 | if (tsk->binfmt)
|
| 1058 | module_put(tsk->binfmt->module);
|
| 1059 |
|
| 1060 | proc_exit_connector(tsk);
|
| 1061 | exit_notify(tsk, group_dead);
|
| 1062 | #ifdef CONFIG_NUMA
|
| 1063 | mpol_put(tsk->mempolicy);
|
| 1064 | tsk->mempolicy = NULL;
|
| 1065 | #endif
|
| 1066 | #ifdef CONFIG_FUTEX
|
| 1067 | |
| 1068 | * This must happen late, after the PID is not
|
| 1069 | * hashed anymore:
|
| 1070 |
|
| 1071 | if (unlikely(!list_empty(&tsk->pi_state_list)))
|
| 1072 | exit_pi_state_list(tsk);
|
| 1073 | if (unlikely(current->pi_state_cache))
|
| 1074 | kfree(current->pi_state_cache);
|
| 1075 | #endif
|
| 1076 | |
| 1077 | * Make sure we are holding no locks:
|
| 1078 |
|
| 1079 | debug_check_no_locks_held(tsk);
|
| 1080 | |
| 1081 | * We can do this unlocked here. The futex code uses this flag
|
| 1082 | * just to verify whether the pi state cleanup has been done
|
| 1083 | * or not. In the worst case it loops once more.
|
| 1084 |
|
| 1085 | tsk->flags |= PF_EXITPIDONE;
|
| 1086 |
|
| 1087 | if (tsk->io_context)
|
| 1088 | exit_io_context();
|
| 1089 |
|
| 1090 | if (tsk->splice_pipe)
|
| 1091 | __free_pipe_info(tsk->splice_pipe);
|
| 1092 |
|
| 1093 | preempt_disable();
|
| 1094 |
|
| 1095 | tsk->state = TASK_DEAD;
|
| 1096 |
|
| 1097 | schedule();
|
| 1098 | BUG();
|
| 1099 |
|
| 1100 | for (;;)
|
| 1101 | cpu_relax();
|
| 1102 | }
|
| 1103 |
|
| 1104 | EXPORT_SYMBOL_GPL(do_exit);
|
| 1105 |
|
| 1106 | NORET_TYPE void complete_and_exit(struct completion *comp, long code)
|
| 1107 | {
|
| 1108 | if (comp)
|
| 1109 | complete(comp);
|
| 1110 |
|
| 1111 | do_exit(code);
|
| 1112 | }
|
| 1113 |
|
| 1114 | EXPORT_SYMBOL(complete_and_exit);
|
| 1115 |
|
| 1116 | asmlinkage long sys_exit(int error_code)
|
| 1117 | {
|
| 1118 | do_exit((error_code&0xff)<<8);
|
| 1119 | }
|
| 1120 |
|
| 1121 | |
| 1122 | * Take down every thread in the group. This is called by fatal signals
|
| 1123 | * as well as by sys_exit_group (below).
|
| 1124 |
|
| 1125 | NORET_TYPE void
|
| 1126 | do_group_exit(int exit_code)
|
| 1127 | {
|
| 1128 | struct signal_struct *sig = current->signal;
|
| 1129 |
|
| 1130 | BUG_ON(exit_code & 0x80);
|
| 1131 |
|
| 1132 | if (signal_group_exit(sig))
|
| 1133 | exit_code = sig->group_exit_code;
|
| 1134 | else if (!thread_group_empty(current)) {
|
| 1135 | struct sighand_struct *const sighand = current->sighand;
|
| 1136 | spin_lock_irq(&sighand->siglock);
|
| 1137 | if (signal_group_exit(sig))
|
| 1138 |
|
| 1139 | exit_code = sig->group_exit_code;
|
| 1140 | else {
|
| 1141 | sig->group_exit_code = exit_code;
|
| 1142 | sig->flags = SIGNAL_GROUP_EXIT;
|
| 1143 | zap_other_threads(current);
|
| 1144 | }
|
| 1145 | spin_unlock_irq(&sighand->siglock);
|
| 1146 | }
|
| 1147 |
|
| 1148 | do_exit(exit_code);
|
| 1149 |
|
| 1150 | }
|
| 1151 |
|
| 1152 | |
| 1153 | * this kills every thread in the thread group. Note that any externally
|
| 1154 | * wait4()-ing process will get the correct exit code - even if this
|
| 1155 | * thread is not the thread group leader.
|
| 1156 |
|
| 1157 | asmlinkage void sys_exit_group(int error_code)
|
| 1158 | {
|
| 1159 | do_group_exit((error_code & 0xff) << 8);
|
| 1160 | }
|
| 1161 |
|
| 1162 | static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
|
| 1163 | {
|
| 1164 | struct pid *pid = NULL;
|
| 1165 | if (type == PIDTYPE_PID)
|
| 1166 | pid = task->pids[type].pid;
|
| 1167 | else if (type < PIDTYPE_MAX)
|
| 1168 | pid = task->group_leader->pids[type].pid;
|
| 1169 | return pid;
|
| 1170 | }
|
| 1171 |
|
| 1172 | static int eligible_child(enum pid_type type, struct pid *pid, int options,
|
| 1173 | struct task_struct *p)
|
| 1174 | {
|
| 1175 | int err;
|
| 1176 |
|
| 1177 | if (type < PIDTYPE_MAX) {
|
| 1178 | if (task_pid_type(p, type) != pid)
|
| 1179 | return 0;
|
| 1180 | }
|
| 1181 |
|
| 1182 | |
| 1183 | * Do not consider detached threads that are
|
| 1184 | * not ptraced:
|
| 1185 |
|
| 1186 | if (task_detached(p) && !p->ptrace)
|
| 1187 | return 0;
|
| 1188 |
|
| 1189 | |
| 1190 | * otherwise, wait for clone children *only* if __WCLONE is
|
| 1191 | * set; otherwise, wait for non-clone children *only*. (Note:
|
| 1192 | * A "clone" child here is one that reports to its parent
|
| 1193 | * using a signal other than SIGCHLD.)
|
| 1194 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
|
| 1195 | && !(options & __WALL))
|
| 1196 | return 0;
|
| 1197 |
|
| 1198 | err = security_task_wait(p);
|
| 1199 | if (likely(!err))
|
| 1200 | return 1;
|
| 1201 |
|
| 1202 | if (type != PIDTYPE_PID)
|
| 1203 | return 0;
|
| 1204 |
|
| 1205 | read_unlock(&tasklist_lock);
|
| 1206 | return err;
|
| 1207 | }
|
| 1208 |
|
| 1209 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
|
| 1210 | int why, int status,
|
| 1211 | struct siginfo __user *infop,
|
| 1212 | struct rusage __user *rusagep)
|
| 1213 | {
|
| 1214 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
|
| 1215 |
|
| 1216 | put_task_struct(p);
|
| 1217 | if (!retval)
|
| 1218 | retval = put_user(SIGCHLD, &infop->si_signo);
|
| 1219 | if (!retval)
|
| 1220 | retval = put_user(0, &infop->si_errno);
|
| 1221 | if (!retval)
|
| 1222 | retval = put_user((short)why, &infop->si_code);
|
| 1223 | if (!retval)
|
| 1224 | retval = put_user(pid, &infop->si_pid);
|
| 1225 | if (!retval)
|
| 1226 | retval = put_user(uid, &infop->si_uid);
|
| 1227 | if (!retval)
|
| 1228 | retval = put_user(status, &infop->si_status);
|
| 1229 | if (!retval)
|
| 1230 | retval = pid;
|
| 1231 | return retval;
|
| 1232 | }
|
| 1233 |
|
| 1234 | |
| 1235 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
|
| 1236 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
|
| 1237 | * the lock and this task is uninteresting. If we return nonzero, we have
|
| 1238 | * released the lock and the system call should return.
|
| 1239 |
|
| 1240 | static int wait_task_zombie(struct task_struct *p, int noreap,
|
| 1241 | struct siginfo __user *infop,
|
| 1242 | int __user *stat_addr, struct rusage __user *ru)
|
| 1243 | {
|
| 1244 | unsigned long state;
|
| 1245 | int retval, status, traced;
|
| 1246 | pid_t pid = task_pid_vnr(p);
|
| 1247 |
|
| 1248 | if (unlikely(noreap)) {
|
| 1249 | uid_t uid = p->uid;
|
| 1250 | int exit_code = p->exit_code;
|
| 1251 | int why, status;
|
| 1252 |
|
| 1253 | get_task_struct(p);
|
| 1254 | read_unlock(&tasklist_lock);
|
| 1255 | if ((exit_code & 0x7f) == 0) {
|
| 1256 | why = CLD_EXITED;
|
| 1257 | status = exit_code >> 8;
|
| 1258 | } else {
|
| 1259 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
|
| 1260 | status = exit_code & 0x7f;
|
| 1261 | }
|
| 1262 | return wait_noreap_copyout(p, pid, uid, why,
|
| 1263 | status, infop, ru);
|
| 1264 | }
|
| 1265 |
|
| 1266 | |
| 1267 | * Try to move the task's state to DEAD
|
| 1268 | * only one thread is allowed to do this:
|
| 1269 |
|
| 1270 | state = xchg(&p->exit_state, EXIT_DEAD);
|
| 1271 | if (state != EXIT_ZOMBIE) {
|
| 1272 | BUG_ON(state != EXIT_DEAD);
|
| 1273 | return 0;
|
| 1274 | }
|
| 1275 |
|
| 1276 | traced = ptrace_reparented(p);
|
| 1277 |
|
| 1278 | if (likely(!traced)) {
|
| 1279 | struct signal_struct *psig;
|
| 1280 | struct signal_struct *sig;
|
| 1281 |
|
| 1282 | |
| 1283 | * The resource counters for the group leader are in its
|
| 1284 | * own task_struct. Those for dead threads in the group
|
| 1285 | * are in its signal_struct, as are those for the child
|
| 1286 | * processes it has previously reaped. All these
|
| 1287 | * accumulate in the parent's signal_struct c* fields.
|
| 1288 | *
|
| 1289 | * We don't bother to take a lock here to protect these
|
| 1290 | * p->signal fields, because they are only touched by
|
| 1291 | * __exit_signal, which runs with tasklist_lock
|
| 1292 | * write-locked anyway, and so is excluded here. We do
|
| 1293 | * need to protect the access to p->parent->signal fields,
|
| 1294 | * as other threads in the parent group can be right
|
| 1295 | * here reaping other children at the same time.
|
| 1296 |
|
| 1297 | spin_lock_irq(&p->parent->sighand->siglock);
|
| 1298 | psig = p->parent->signal;
|
| 1299 | sig = p->signal;
|
| 1300 | psig->cutime =
|
| 1301 | cputime_add(psig->cutime,
|
| 1302 | cputime_add(p->utime,
|
| 1303 | cputime_add(sig->utime,
|
| 1304 | sig->cutime)));
|
| 1305 | psig->cstime =
|
| 1306 | cputime_add(psig->cstime,
|
| 1307 | cputime_add(p->stime,
|
| 1308 | cputime_add(sig->stime,
|
| 1309 | sig->cstime)));
|
| 1310 | psig->cgtime =
|
| 1311 | cputime_add(psig->cgtime,
|
| 1312 | cputime_add(p->gtime,
|
| 1313 | cputime_add(sig->gtime,
|
| 1314 | sig->cgtime)));
|
| 1315 | psig->cmin_flt +=
|
| 1316 | p->min_flt + sig->min_flt + sig->cmin_flt;
|
| 1317 | psig->cmaj_flt +=
|
| 1318 | p->maj_flt + sig->maj_flt + sig->cmaj_flt;
|
| 1319 | psig->cnvcsw +=
|
| 1320 | p->nvcsw + sig->nvcsw + sig->cnvcsw;
|
| 1321 | psig->cnivcsw +=
|
| 1322 | p->nivcsw + sig->nivcsw + sig->cnivcsw;
|
| 1323 | psig->cinblock +=
|
| 1324 | task_io_get_inblock(p) +
|
| 1325 | sig->inblock + sig->cinblock;
|
| 1326 | psig->coublock +=
|
| 1327 | task_io_get_oublock(p) +
|
| 1328 | sig->oublock + sig->coublock;
|
| 1329 | spin_unlock_irq(&p->parent->sighand->siglock);
|
| 1330 | }
|
| 1331 |
|
| 1332 | |
| 1333 | * Now we are sure this task is interesting, and no other
|
| 1334 | * thread can reap it because we set its state to EXIT_DEAD.
|
| 1335 |
|
| 1336 | read_unlock(&tasklist_lock);
|
| 1337 |
|
| 1338 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
|
| 1339 | status = (p->signal->flags & SIGNAL_GROUP_EXIT)
|
| 1340 | ? p->signal->group_exit_code : p->exit_code;
|
| 1341 | if (!retval && stat_addr)
|
| 1342 | retval = put_user(status, stat_addr);
|
| 1343 | if (!retval && infop)
|
| 1344 | retval = put_user(SIGCHLD, &infop->si_signo);
|
| 1345 | if (!retval && infop)
|
| 1346 | retval = put_user(0, &infop->si_errno);
|
| 1347 | if (!retval && infop) {
|
| 1348 | int why;
|
| 1349 |
|
| 1350 | if ((status & 0x7f) == 0) {
|
| 1351 | why = CLD_EXITED;
|
| 1352 | status >>= 8;
|
| 1353 | } else {
|
| 1354 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
|
| 1355 | status &= 0x7f;
|
| 1356 | }
|
| 1357 | retval = put_user((short)why, &infop->si_code);
|
| 1358 | if (!retval)
|
| 1359 | retval = put_user(status, &infop->si_status);
|
| 1360 | }
|
| 1361 | if (!retval && infop)
|
| 1362 | retval = put_user(pid, &infop->si_pid);
|
| 1363 | if (!retval && infop)
|
| 1364 | retval = put_user(p->uid, &infop->si_uid);
|
| 1365 | if (!retval)
|
| 1366 | retval = pid;
|
| 1367 |
|
| 1368 | if (traced) {
|
| 1369 | write_lock_irq(&tasklist_lock);
|
| 1370 |
|
| 1371 | ptrace_unlink(p);
|
| 1372 | |
| 1373 | * If this is not a detached task, notify the parent.
|
| 1374 | * If it's still not detached after that, don't release
|
| 1375 | * it now.
|
| 1376 |
|
| 1377 | if (!task_detached(p)) {
|
| 1378 | do_notify_parent(p, p->exit_signal);
|
| 1379 | if (!task_detached(p)) {
|
| 1380 | p->exit_state = EXIT_ZOMBIE;
|
| 1381 | p = NULL;
|
| 1382 | }
|
| 1383 | }
|
| 1384 | write_unlock_irq(&tasklist_lock);
|
| 1385 | }
|
| 1386 | if (p != NULL)
|
| 1387 | release_task(p);
|
| 1388 |
|
| 1389 | return retval;
|
| 1390 | }
|
| 1391 |
|
| 1392 | |
| 1393 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
|
| 1394 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
|
| 1395 | * the lock and this task is uninteresting. If we return nonzero, we have
|
| 1396 | * released the lock and the system call should return.
|
| 1397 |
|
| 1398 | static int wait_task_stopped(struct task_struct *p,
|
| 1399 | int noreap, struct siginfo __user *infop,
|
| 1400 | int __user *stat_addr, struct rusage __user *ru)
|
| 1401 | {
|
| 1402 | int retval, exit_code, why;
|
| 1403 | uid_t uid = 0;
|
| 1404 | pid_t pid;
|
| 1405 |
|
| 1406 | exit_code = 0;
|
| 1407 | spin_lock_irq(&p->sighand->siglock);
|
| 1408 |
|
| 1409 | if (unlikely(!task_is_stopped_or_traced(p)))
|
| 1410 | goto unlock_sig;
|
| 1411 |
|
| 1412 | if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0)
|
| 1413 | |
| 1414 | * A group stop is in progress and this is the group leader.
|
| 1415 | * We won't report until all threads have stopped.
|
| 1416 |
|
| 1417 | goto unlock_sig;
|
| 1418 |
|
| 1419 | exit_code = p->exit_code;
|
| 1420 | if (!exit_code)
|
| 1421 | goto unlock_sig;
|
| 1422 |
|
| 1423 | if (!noreap)
|
| 1424 | p->exit_code = 0;
|
| 1425 |
|
| 1426 | uid = p->uid;
|
| 1427 | unlock_sig:
|
| 1428 | spin_unlock_irq(&p->sighand->siglock);
|
| 1429 | if (!exit_code)
|
| 1430 | return 0;
|
| 1431 |
|
| 1432 | |
| 1433 | * Now we are pretty sure this task is interesting.
|
| 1434 | * Make sure it doesn't get reaped out from under us while we
|
| 1435 | * give up the lock and then examine it below. We don't want to
|
| 1436 | * keep holding onto the tasklist_lock while we call getrusage and
|
| 1437 | * possibly take page faults for user memory.
|
| 1438 |
|
| 1439 | get_task_struct(p);
|
| 1440 | pid = task_pid_vnr(p);
|
| 1441 | why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
|
| 1442 | read_unlock(&tasklist_lock);
|
| 1443 |
|
| 1444 | if (unlikely(noreap))
|
| 1445 | return wait_noreap_copyout(p, pid, uid,
|
| 1446 | why, exit_code,
|
| 1447 | infop, ru);
|
| 1448 |
|
| 1449 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
|
| 1450 | if (!retval && stat_addr)
|
| 1451 | retval = put_user((exit_code << 8) | 0x7f, stat_addr);
|
| 1452 | if (!retval && infop)
|
| 1453 | retval = put_user(SIGCHLD, &infop->si_signo);
|
| 1454 | if (!retval && infop)
|
| 1455 | retval = put_user(0, &infop->si_errno);
|
| 1456 | if (!retval && infop)
|
| 1457 | retval = put_user((short)why, &infop->si_code);
|
| 1458 | if (!retval && infop)
|
| 1459 | retval = put_user(exit_code, &infop->si_status);
|
| 1460 | if (!retval && infop)
|
| 1461 | retval = put_user(pid, &infop->si_pid);
|
| 1462 | if (!retval && infop)
|
| 1463 | retval = put_user(uid, &infop->si_uid);
|
| 1464 | if (!retval)
|
| 1465 | retval = pid;
|
| 1466 | put_task_struct(p);
|
| 1467 |
|
| 1468 | BUG_ON(!retval);
|
| 1469 | return retval;
|
| 1470 | }
|
| 1471 |
|
| 1472 | |
| 1473 | * Handle do_wait work for one task in a live, non-stopped state.
|
| 1474 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
|
| 1475 | * the lock and this task is uninteresting. If we return nonzero, we have
|
| 1476 | * released the lock and the system call should return.
|
| 1477 |
|
| 1478 | static int wait_task_continued(struct task_struct *p, int noreap,
|
| 1479 | struct siginfo __user *infop,
|
| 1480 | int __user *stat_addr, struct rusage __user *ru)
|
| 1481 | {
|
| 1482 | int retval;
|
| 1483 | pid_t pid;
|
| 1484 | uid_t uid;
|
| 1485 |
|
| 1486 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
|
| 1487 | return 0;
|
| 1488 |
|
| 1489 | spin_lock_irq(&p->sighand->siglock);
|
| 1490 |
|
| 1491 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
|
| 1492 | spin_unlock_irq(&p->sighand->siglock);
|
| 1493 | return 0;
|
| 1494 | }
|
| 1495 | if (!noreap)
|
| 1496 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
|
| 1497 | spin_unlock_irq(&p->sighand->siglock);
|
| 1498 |
|
| 1499 | pid = task_pid_vnr(p);
|
| 1500 | uid = p->uid;
|
| 1501 | get_task_struct(p);
|
| 1502 | read_unlock(&tasklist_lock);
|
| 1503 |
|
| 1504 | if (!infop) {
|
| 1505 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
|
| 1506 | put_task_struct(p);
|
| 1507 | if (!retval && stat_addr)
|
| 1508 | retval = put_user(0xffff, stat_addr);
|
| 1509 | if (!retval)
|
| 1510 | retval = pid;
|
| 1511 | } else {
|
| 1512 | retval = wait_noreap_copyout(p, pid, uid,
|
| 1513 | CLD_CONTINUED, SIGCONT,
|
| 1514 | infop, ru);
|
| 1515 | BUG_ON(retval == 0);
|
| 1516 | }
|
| 1517 |
|
| 1518 | return retval;
|
| 1519 | }
|
| 1520 |
|
| 1521 | static long do_wait(enum pid_type type, struct pid *pid, int options,
|
| 1522 | struct siginfo __user *infop, int __user *stat_addr,
|
| 1523 | struct rusage __user *ru)
|
| 1524 | {
|
| 1525 | DECLARE_WAITQUEUE(wait, current);
|
| 1526 | struct task_struct *tsk;
|
| 1527 | int flag, retval;
|
| 1528 |
|
| 1529 | add_wait_queue(¤t->signal->wait_chldexit,&wait);
|
| 1530 | repeat:
|
| 1531 |
|
| 1532 | retval = -ECHILD;
|
| 1533 | if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type])))
|
| 1534 | goto end;
|
| 1535 |
|
| 1536 | |
| 1537 | * We will set this flag if we see any child that might later
|
| 1538 | * match our criteria, even if we are not able to reap it yet.
|
| 1539 |
|
| 1540 | flag = retval = 0;
|
| 1541 | current->state = TASK_INTERRUPTIBLE;
|
| 1542 | read_lock(&tasklist_lock);
|
| 1543 | tsk = current;
|
| 1544 | do {
|
| 1545 | struct task_struct *p;
|
| 1546 |
|
| 1547 | list_for_each_entry(p, &tsk->children, sibling) {
|
| 1548 | int ret = eligible_child(type, pid, options, p);
|
| 1549 | if (!ret)
|
| 1550 | continue;
|
| 1551 |
|
| 1552 | if (unlikely(ret < 0)) {
|
| 1553 | retval = ret;
|
| 1554 | } else if (task_is_stopped_or_traced(p)) {
|
| 1555 | |
| 1556 | * It's stopped now, so it might later
|
| 1557 | * continue, exit, or stop again.
|
| 1558 |
|
| 1559 | flag = 1;
|
| 1560 | if (!(p->ptrace & PT_PTRACED) &&
|
| 1561 | !(options & WUNTRACED))
|
| 1562 | continue;
|
| 1563 |
|
| 1564 | retval = wait_task_stopped(p,
|
| 1565 | (options & WNOWAIT), infop,
|
| 1566 | stat_addr, ru);
|
| 1567 | } else if (p->exit_state == EXIT_ZOMBIE &&
|
| 1568 | !delay_group_leader(p)) {
|
| 1569 | |
| 1570 | * We don't reap group leaders with subthreads.
|
| 1571 |
|
| 1572 | if (!likely(options & WEXITED))
|
| 1573 | continue;
|
| 1574 | retval = wait_task_zombie(p,
|
| 1575 | (options & WNOWAIT), infop,
|
| 1576 | stat_addr, ru);
|
| 1577 | } else if (p->exit_state != EXIT_DEAD) {
|
| 1578 | |
| 1579 | * It's running now, so it might later
|
| 1580 | * exit, stop, or stop and then continue.
|
| 1581 |
|
| 1582 | flag = 1;
|
| 1583 | if (!unlikely(options & WCONTINUED))
|
| 1584 | continue;
|
| 1585 | retval = wait_task_continued(p,
|
| 1586 | (options & WNOWAIT), infop,
|
| 1587 | stat_addr, ru);
|
| 1588 | }
|
| 1589 | if (retval != 0)
|
| 1590 | goto end;
|
| 1591 | }
|
| 1592 | if (!flag) {
|
| 1593 | list_for_each_entry(p, &tsk->ptrace_children,
|
| 1594 | ptrace_list) {
|
| 1595 | flag = eligible_child(type, pid, options, p);
|
| 1596 | if (!flag)
|
| 1597 | continue;
|
| 1598 | if (likely(flag > 0))
|
| 1599 | break;
|
| 1600 | retval = flag;
|
| 1601 | goto end;
|
| 1602 | }
|
| 1603 | }
|
| 1604 | if (options & __WNOTHREAD)
|
| 1605 | break;
|
| 1606 | tsk = next_thread(tsk);
|
| 1607 | BUG_ON(tsk->signal != current->signal);
|
| 1608 | } while (tsk != current);
|
| 1609 | read_unlock(&tasklist_lock);
|
| 1610 |
|
| 1611 | if (flag) {
|
| 1612 | if (options & WNOHANG)
|
| 1613 | goto end;
|
| 1614 | retval = -ERESTARTSYS;
|
| 1615 | if (signal_pending(current))
|
| 1616 | goto end;
|
| 1617 | schedule();
|
| 1618 | goto repeat;
|
| 1619 | }
|
| 1620 | retval = -ECHILD;
|
| 1621 | end:
|
| 1622 | current->state = TASK_RUNNING;
|
| 1623 | remove_wait_queue(¤t->signal->wait_chldexit,&wait);
|
| 1624 | if (infop) {
|
| 1625 | if (retval > 0)
|
| 1626 | retval = 0;
|
| 1627 | else {
|
| 1628 | |
| 1629 | * For a WNOHANG return, clear out all the fields
|
| 1630 | * we would set so the user can easily tell the
|
| 1631 | * difference.
|
| 1632 |
|
| 1633 | if (!retval)
|
| 1634 | retval = put_user(0, &infop->si_signo);
|
| 1635 | if (!retval)
|
| 1636 | retval = put_user(0, &infop->si_errno);
|
| 1637 | if (!retval)
|
| 1638 | retval = put_user(0, &infop->si_code);
|
| 1639 | if (!retval)
|
| 1640 | retval = put_user(0, &infop->si_pid);
|
| 1641 | if (!retval)
|
| 1642 | retval = put_user(0, &infop->si_uid);
|
| 1643 | if (!retval)
|
| 1644 | retval = put_user(0, &infop->si_status);
|
| 1645 | }
|
| 1646 | }
|
| 1647 | return retval;
|
| 1648 | }
|
| 1649 |
|
| 1650 | asmlinkage long sys_waitid(int which, pid_t upid,
|
| 1651 | struct siginfo __user *infop, int options,
|
| 1652 | struct rusage __user *ru)
|
| 1653 | {
|
| 1654 | struct pid *pid = NULL;
|
| 1655 | enum pid_type type;
|
| 1656 | long ret;
|
| 1657 |
|
| 1658 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
|
| 1659 | return -EINVAL;
|
| 1660 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
|
| 1661 | return -EINVAL;
|
| 1662 |
|
| 1663 | switch (which) {
|
| 1664 | case P_ALL:
|
| 1665 | type = PIDTYPE_MAX;
|
| 1666 | break;
|
| 1667 | case P_PID:
|
| 1668 | type = PIDTYPE_PID;
|
| 1669 | if (upid <= 0)
|
| 1670 | return -EINVAL;
|
| 1671 | break;
|
| 1672 | case P_PGID:
|
| 1673 | type = PIDTYPE_PGID;
|
| 1674 | if (upid <= 0)
|
| 1675 | return -EINVAL;
|
| 1676 | break;
|
| 1677 | default:
|
| 1678 | return -EINVAL;
|
| 1679 | }
|
| 1680 |
|
| 1681 | if (type < PIDTYPE_MAX)
|
| 1682 | pid = find_get_pid(upid);
|
| 1683 | ret = do_wait(type, pid, options, infop, NULL, ru);
|
| 1684 | put_pid(pid);
|
| 1685 |
|
| 1686 |
|
| 1687 | asmlinkage_protect(5, ret, which, upid, infop, options, ru);
|
| 1688 | return ret;
|
| 1689 | }
|
| 1690 |
|
| 1691 | asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
|
| 1692 | int options, struct rusage __user *ru)
|
| 1693 | {
|
| 1694 | struct pid *pid = NULL;
|
| 1695 | enum pid_type type;
|
| 1696 | long ret;
|
| 1697 |
|
| 1698 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
|
| 1699 | __WNOTHREAD|__WCLONE|__WALL))
|
| 1700 | return -EINVAL;
|
| 1701 |
|
| 1702 | if (upid == -1)
|
| 1703 | type = PIDTYPE_MAX;
|
| 1704 | else if (upid < 0) {
|
| 1705 | type = PIDTYPE_PGID;
|
| 1706 | pid = find_get_pid(-upid);
|
| 1707 | } else if (upid == 0) {
|
| 1708 | type = PIDTYPE_PGID;
|
| 1709 | pid = get_pid(task_pgrp(current));
|
| 1710 | } else {
|
| 1711 | type = PIDTYPE_PID;
|
| 1712 | pid = find_get_pid(upid);
|
| 1713 | }
|
| 1714 |
|
| 1715 | ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru);
|
| 1716 | put_pid(pid);
|
| 1717 |
|
| 1718 |
|
| 1719 | asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
|
| 1720 | return ret;
|
| 1721 | }
|
| 1722 |
|
| 1723 | #ifdef __ARCH_WANT_SYS_WAITPID
|
| 1724 |
|
| 1725 | |
| 1726 | * sys_waitpid() remains for compatibility. waitpid() should be
|
| 1727 | * implemented by calling sys_wait4() from libc.a.
|
| 1728 |
|
| 1729 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
|
| 1730 | {
|
| 1731 | return sys_wait4(pid, stat_addr, options, NULL);
|
| 1732 | }
|
| 1733 |
|
| 1734 | #endif
|