| /* |
| * linux/kernel/exit.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| #include <linux/smp_lock.h> |
| #include <linux/module.h> |
| #include <linux/capability.h> |
| #include <linux/completion.h> |
| #include <linux/personality.h> |
| #include <linux/tty.h> |
| #include <linux/mnt_namespace.h> |
| #include <linux/key.h> |
| #include <linux/security.h> |
| #include <linux/cpu.h> |
| #include <linux/acct.h> |
| #include <linux/tsacct_kern.h> |
| #include <linux/file.h> |
| #include <linux/binfmts.h> |
| #include <linux/nsproxy.h> |
| #include <linux/pid_namespace.h> |
| #include <linux/ptrace.h> |
| #include <linux/profile.h> |
| #include <linux/mount.h> |
| #include <linux/proc_fs.h> |
| #include <linux/mempolicy.h> |
| #include <linux/taskstats_kern.h> |
| #include <linux/delayacct.h> |
| #include <linux/cpuset.h> |
| #include <linux/syscalls.h> |
| #include <linux/signal.h> |
| #include <linux/posix-timers.h> |
| #include <linux/cn_proc.h> |
| #include <linux/mutex.h> |
| #include <linux/futex.h> |
| #include <linux/compat.h> |
| #include <linux/pipe_fs_i.h> |
| #include <linux/audit.h> /* for audit_free() */ |
| #include <linux/resource.h> |
| #include <linux/blkdev.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/unistd.h> |
| #include <asm/pgtable.h> |
| #include <asm/mmu_context.h> |
| |
| extern void sem_exit (void); |
| |
| static void exit_mm(struct task_struct * tsk); |
| |
| static void __unhash_process(struct task_struct *p) |
| { |
| nr_threads--; |
| detach_pid(p, PIDTYPE_PID); |
| if (thread_group_leader(p)) { |
| detach_pid(p, PIDTYPE_PGID); |
| detach_pid(p, PIDTYPE_SID); |
| |
| list_del_rcu(&p->tasks); |
| __get_cpu_var(process_counts)--; |
| } |
| list_del_rcu(&p->thread_group); |
| remove_parent(p); |
| } |
| |
| /* |
| * This function expects the tasklist_lock write-locked. |
| */ |
| static void __exit_signal(struct task_struct *tsk) |
| { |
| struct signal_struct *sig = tsk->signal; |
| struct sighand_struct *sighand; |
| |
| BUG_ON(!sig); |
| BUG_ON(!atomic_read(&sig->count)); |
| |
| rcu_read_lock(); |
| sighand = rcu_dereference(tsk->sighand); |
| spin_lock(&sighand->siglock); |
| |
| posix_cpu_timers_exit(tsk); |
| if (atomic_dec_and_test(&sig->count)) |
| posix_cpu_timers_exit_group(tsk); |
| else { |
| /* |
| * If there is any task waiting for the group exit |
| * then notify it: |
| */ |
| if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) { |
| wake_up_process(sig->group_exit_task); |
| sig->group_exit_task = NULL; |
| } |
| if (tsk == sig->curr_target) |
| sig->curr_target = next_thread(tsk); |
| /* |
| * Accumulate here the counters for all threads but the |
| * group leader as they die, so they can be added into |
| * the process-wide totals when those are taken. |
| * The group leader stays around as a zombie as long |
| * as there are other threads. When it gets reaped, |
| * the exit.c code will add its counts into these totals. |
| * We won't ever get here for the group leader, since it |
| * will have been the last reference on the signal_struct. |
| */ |
| sig->utime = cputime_add(sig->utime, tsk->utime); |
| sig->stime = cputime_add(sig->stime, tsk->stime); |
| sig->min_flt += tsk->min_flt; |
| sig->maj_flt += tsk->maj_flt; |
| sig->nvcsw += tsk->nvcsw; |
| sig->nivcsw += tsk->nivcsw; |
| sig->sched_time += tsk->sched_time; |
| sig = NULL; /* Marker for below. */ |
| } |
| |
| __unhash_process(tsk); |
| |
| tsk->signal = NULL; |
| tsk->sighand = NULL; |
| spin_unlock(&sighand->siglock); |
| rcu_read_unlock(); |
| |
| __cleanup_sighand(sighand); |
| clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
| flush_sigqueue(&tsk->pending); |
| if (sig) { |
| flush_sigqueue(&sig->shared_pending); |
| taskstats_tgid_free(sig); |
| __cleanup_signal(sig); |
| } |
| } |
| |
| static void delayed_put_task_struct(struct rcu_head *rhp) |
| { |
| put_task_struct(container_of(rhp, struct task_struct, rcu)); |
| } |
| |
| void release_task(struct task_struct * p) |
| { |
| struct task_struct *leader; |
| int zap_leader; |
| repeat: |
| atomic_dec(&p->user->processes); |
| write_lock_irq(&tasklist_lock); |
| ptrace_unlink(p); |
| BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); |
| __exit_signal(p); |
| |
| /* |
| * If we are the last non-leader member of the thread |
| * group, and the leader is zombie, then notify the |
| * group leader's parent process. (if it wants notification.) |
| */ |
| zap_leader = 0; |
| leader = p->group_leader; |
| if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { |
| BUG_ON(leader->exit_signal == -1); |
| do_notify_parent(leader, leader->exit_signal); |
| /* |
| * If we were the last child thread and the leader has |
| * exited already, and the leader's parent ignores SIGCHLD, |
| * then we are the one who should release the leader. |
| * |
| * do_notify_parent() will have marked it self-reaping in |
| * that case. |
| */ |
| zap_leader = (leader->exit_signal == -1); |
| } |
| |
| sched_exit(p); |
| write_unlock_irq(&tasklist_lock); |
| proc_flush_task(p); |
| release_thread(p); |
| call_rcu(&p->rcu, delayed_put_task_struct); |
| |
| p = leader; |
| if (unlikely(zap_leader)) |
| goto repeat; |
| } |
| |
| /* |
| * This checks not only the pgrp, but falls back on the pid if no |
| * satisfactory pgrp is found. I dunno - gdb doesn't work correctly |
| * without this... |
| */ |
| int session_of_pgrp(int pgrp) |
| { |
| struct task_struct *p; |
| int sid = 0; |
| |
| read_lock(&tasklist_lock); |
| |
| p = find_task_by_pid_type(PIDTYPE_PGID, pgrp); |
| if (p == NULL) |
| p = find_task_by_pid(pgrp); |
| if (p != NULL) |
| sid = process_session(p); |
| |
| read_unlock(&tasklist_lock); |
| |
| return sid; |
| } |
| |
| /* |
| * Determine if a process group is "orphaned", according to the POSIX |
| * definition in 2.2.2.52. Orphaned process groups are not to be affected |
| * by terminal-generated stop signals. Newly orphaned process groups are |
| * to receive a SIGHUP and a SIGCONT. |
| * |
| * "I ask you, have you ever known what it is to be an orphan?" |
| */ |
| static int will_become_orphaned_pgrp(int pgrp, struct task_struct *ignored_task) |
| { |
| struct task_struct *p; |
| int ret = 1; |
| |
| do_each_task_pid(pgrp, PIDTYPE_PGID, p) { |
| if (p == ignored_task |
| || p->exit_state |
| || is_init(p->real_parent)) |
| continue; |
| if (process_group(p->real_parent) != pgrp && |
| process_session(p->real_parent) == process_session(p)) { |
| ret = 0; |
| break; |
| } |
| } while_each_task_pid(pgrp, PIDTYPE_PGID, p); |
| return ret; /* (sighing) "Often!" */ |
| } |
| |
| int is_orphaned_pgrp(int pgrp) |
| { |
| int retval; |
| |
| read_lock(&tasklist_lock); |
| retval = will_become_orphaned_pgrp(pgrp, NULL); |
| read_unlock(&tasklist_lock); |
| |
| return retval; |
| } |
| |
| static int has_stopped_jobs(int pgrp) |
| { |
| int retval = 0; |
| struct task_struct *p; |
| |
| do_each_task_pid(pgrp, PIDTYPE_PGID, p) { |
| if (p->state != TASK_STOPPED) |
| continue; |
| retval = 1; |
| break; |
| } while_each_task_pid(pgrp, PIDTYPE_PGID, p); |
| return retval; |
| } |
| |
| /** |
| * reparent_to_init - Reparent the calling kernel thread to the init task |
| * of the pid space that the thread belongs to. |
| * |
| * If a kernel thread is launched as a result of a system call, or if |
| * it ever exits, it should generally reparent itself to init so that |
| * it is correctly cleaned up on exit. |
| * |
| * The various task state such as scheduling policy and priority may have |
| * been inherited from a user process, so we reset them to sane values here. |
| * |
| * NOTE that reparent_to_init() gives the caller full capabilities. |
| */ |
| static void reparent_to_init(void) |
| { |
| write_lock_irq(&tasklist_lock); |
| |
| ptrace_unlink(current); |
| /* Reparent to init */ |
| remove_parent(current); |
| current->parent = child_reaper(current); |
| current->real_parent = child_reaper(current); |
| add_parent(current); |
| |
| /* Set the exit signal to SIGCHLD so we signal init on exit */ |
| current->exit_signal = SIGCHLD; |
| |
| if (!has_rt_policy(current) && (task_nice(current) < 0)) |
| set_user_nice(current, 0); |
| /* cpus_allowed? */ |
| /* rt_priority? */ |
| /* signals? */ |
| security_task_reparent_to_init(current); |
| memcpy(current->signal->rlim, init_task.signal->rlim, |
| sizeof(current->signal->rlim)); |
| atomic_inc(&(INIT_USER->__count)); |
| write_unlock_irq(&tasklist_lock); |
| switch_uid(INIT_USER); |
| } |
| |
| void __set_special_pids(pid_t session, pid_t pgrp) |
| { |
| struct task_struct *curr = current->group_leader; |
| |
| if (process_session(curr) != session) { |
| detach_pid(curr, PIDTYPE_SID); |
| set_signal_session(curr->signal, session); |
| attach_pid(curr, PIDTYPE_SID, session); |
| } |
| if (process_group(curr) != pgrp) { |
| detach_pid(curr, PIDTYPE_PGID); |
| curr->signal->pgrp = pgrp; |
| attach_pid(curr, PIDTYPE_PGID, pgrp); |
| } |
| } |
| |
| static void set_special_pids(pid_t session, pid_t pgrp) |
| { |
| write_lock_irq(&tasklist_lock); |
| __set_special_pids(session, pgrp); |
| write_unlock_irq(&tasklist_lock); |
| } |
| |
| /* |
| * Let kernel threads use this to say that they |
| * allow a certain signal (since daemonize() will |
| * have disabled all of them by default). |
| */ |
| int allow_signal(int sig) |
| { |
| if (!valid_signal(sig) || sig < 1) |
| return -EINVAL; |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| sigdelset(¤t->blocked, sig); |
| if (!current->mm) { |
| /* Kernel threads handle their own signals. |
| Let the signal code know it'll be handled, so |
| that they don't get converted to SIGKILL or |
| just silently dropped */ |
| current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; |
| } |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| return 0; |
| } |
| |
| EXPORT_SYMBOL(allow_signal); |
| |
| int disallow_signal(int sig) |
| { |
| if (!valid_signal(sig) || sig < 1) |
| return -EINVAL; |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| sigaddset(¤t->blocked, sig); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| return 0; |
| } |
| |
| EXPORT_SYMBOL(disallow_signal); |
| |
| /* |
| * Put all the gunge required to become a kernel thread without |
| * attached user resources in one place where it belongs. |
| */ |
| |
| void daemonize(const char *name, ...) |
| { |
| va_list args; |
| struct fs_struct *fs; |
| sigset_t blocked; |
| |
| va_start(args, name); |
| vsnprintf(current->comm, sizeof(current->comm), name, args); |
| va_end(args); |
| |
| /* |
| * If we were started as result of loading a module, close all of the |
| * user space pages. We don't need them, and if we didn't close them |
| * they would be locked into memory. |
| */ |
| exit_mm(current); |
| |
| set_special_pids(1, 1); |
| proc_clear_tty(current); |
| |
| /* Block and flush all signals */ |
| sigfillset(&blocked); |
| sigprocmask(SIG_BLOCK, &blocked, NULL); |
| flush_signals(current); |
| |
| /* Become as one with the init task */ |
| |
| exit_fs(current); /* current->fs->count--; */ |
| fs = init_task.fs; |
| current->fs = fs; |
| atomic_inc(&fs->count); |
| |
| exit_task_namespaces(current); |
| current->nsproxy = init_task.nsproxy; |
| get_task_namespaces(current); |
| |
| exit_files(current); |
| current->files = init_task.files; |
| atomic_inc(¤t->files->count); |
| |
| reparent_to_init(); |
| } |
| |
| EXPORT_SYMBOL(daemonize); |
| |
| static void close_files(struct files_struct * files) |
| { |
| int i, j; |
| struct fdtable *fdt; |
| |
| j = 0; |
| |
| /* |
| * It is safe to dereference the fd table without RCU or |
| * ->file_lock because this is the last reference to the |
| * files structure. |
| */ |
| fdt = files_fdtable(files); |
| for (;;) { |
| unsigned long set; |
| i = j * __NFDBITS; |
| if (i >= fdt->max_fds) |
| break; |
| set = fdt->open_fds->fds_bits[j++]; |
| while (set) { |
| if (set & 1) { |
| struct file * file = xchg(&fdt->fd[i], NULL); |
| if (file) |
| filp_close(file, files); |
| } |
| i++; |
| set >>= 1; |
| } |
| } |
| } |
| |
| struct files_struct *get_files_struct(struct task_struct *task) |
| { |
| struct files_struct *files; |
| |
| task_lock(task); |
| files = task->files; |
| if (files) |
| atomic_inc(&files->count); |
| task_unlock(task); |
| |
| return files; |
| } |
| |
| void fastcall put_files_struct(struct files_struct *files) |
| { |
| struct fdtable *fdt; |
| |
| if (atomic_dec_and_test(&files->count)) { |
| close_files(files); |
| /* |
| * Free the fd and fdset arrays if we expanded them. |
| * If the fdtable was embedded, pass files for freeing |
| * at the end of the RCU grace period. Otherwise, |
| * you can free files immediately. |
| */ |
| fdt = files_fdtable(files); |
| if (fdt != &files->fdtab) |
| kmem_cache_free(files_cachep, files); |
| free_fdtable(fdt); |
| } |
| } |
| |
| EXPORT_SYMBOL(put_files_struct); |
| |
| void reset_files_struct(struct task_struct *tsk, struct files_struct *files) |
| { |
| struct files_struct *old; |
| |
| old = tsk->files; |
| task_lock(tsk); |
| tsk->files = files; |
| task_unlock(tsk); |
| put_files_struct(old); |
| } |
| EXPORT_SYMBOL(reset_files_struct); |
| |
| static inline void __exit_files(struct task_struct *tsk) |
| { |
| struct files_struct * files = tsk->files; |
| |
| if (files) { |
| task_lock(tsk); |
| tsk->files = NULL; |
| task_unlock(tsk); |
| put_files_struct(files); |
| } |
| } |
| |
| void exit_files(struct task_struct *tsk) |
| { |
| __exit_files(tsk); |
| } |
| |
| static inline void __put_fs_struct(struct fs_struct *fs) |
| { |
| /* No need to hold fs->lock if we are killing it */ |
| if (atomic_dec_and_test(&fs->count)) { |
| dput(fs->root); |
| mntput(fs->rootmnt); |
| dput(fs->pwd); |
| mntput(fs->pwdmnt); |
| if (fs->altroot) { |
| dput(fs->altroot); |
| mntput(fs->altrootmnt); |
| } |
| kmem_cache_free(fs_cachep, fs); |
| } |
| } |
| |
| void put_fs_struct(struct fs_struct *fs) |
| { |
| __put_fs_struct(fs); |
| } |
| |
| static inline void __exit_fs(struct task_struct *tsk) |
| { |
| struct fs_struct * fs = tsk->fs; |
| |
| if (fs) { |
| task_lock(tsk); |
| tsk->fs = NULL; |
| task_unlock(tsk); |
| __put_fs_struct(fs); |
| } |
| } |
| |
| void exit_fs(struct task_struct *tsk) |
| { |
| __exit_fs(tsk); |
| } |
| |
| EXPORT_SYMBOL_GPL(exit_fs); |
| |
| /* |
| * Turn us into a lazy TLB process if we |
| * aren't already.. |
| */ |
| static void exit_mm(struct task_struct * tsk) |
| { |
| struct mm_struct *mm = tsk->mm; |
| |
| mm_release(tsk, mm); |
| if (!mm) |
| return; |
| /* |
| * Serialize with any possible pending coredump. |
| * We must hold mmap_sem around checking core_waiters |
| * and clearing tsk->mm. The core-inducing thread |
| * will increment core_waiters for each thread in the |
| * group with ->mm != NULL. |
| */ |
| down_read(&mm->mmap_sem); |
| if (mm->core_waiters) { |
| up_read(&mm->mmap_sem); |
| down_write(&mm->mmap_sem); |
| if (!--mm->core_waiters) |
| complete(mm->core_startup_done); |
| up_write(&mm->mmap_sem); |
| |
| wait_for_completion(&mm->core_done); |
| down_read(&mm->mmap_sem); |
| } |
| atomic_inc(&mm->mm_count); |
| BUG_ON(mm != tsk->active_mm); |
| /* more a memory barrier than a real lock */ |
| task_lock(tsk); |
| tsk->mm = NULL; |
| up_read(&mm->mmap_sem); |
| enter_lazy_tlb(mm, current); |
| task_unlock(tsk); |
| mmput(mm); |
| } |
| |
| static inline void |
| choose_new_parent(struct task_struct *p, struct task_struct *reaper) |
| { |
| /* |
| * Make sure we're not reparenting to ourselves and that |
| * the parent is not a zombie. |
| */ |
| BUG_ON(p == reaper || reaper->exit_state); |
| p->real_parent = reaper; |
| } |
| |
| static void |
| reparent_thread(struct task_struct *p, struct task_struct *father, int traced) |
| { |
| /* We don't want people slaying init. */ |
| if (p->exit_signal != -1) |
| p->exit_signal = SIGCHLD; |
| |
| if (p->pdeath_signal) |
| /* We already hold the tasklist_lock here. */ |
| group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); |
| |
| /* Move the child from its dying parent to the new one. */ |
| if (unlikely(traced)) { |
| /* Preserve ptrace links if someone else is tracing this child. */ |
| list_del_init(&p->ptrace_list); |
| if (p->parent != p->real_parent) |
| list_add(&p->ptrace_list, &p->real_parent->ptrace_children); |
| } else { |
| /* If this child is being traced, then we're the one tracing it |
| * anyway, so let go of it. |
| */ |
| p->ptrace = 0; |
| remove_parent(p); |
| p->parent = p->real_parent; |
| add_parent(p); |
| |
| /* If we'd notified the old parent about this child's death, |
| * also notify the new parent. |
| */ |
| if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 && |
| thread_group_empty(p)) |
| do_notify_parent(p, p->exit_signal); |
| else if (p->state == TASK_TRACED) { |
| /* |
| * If it was at a trace stop, turn it into |
| * a normal stop since it's no longer being |
| * traced. |
| */ |
| ptrace_untrace(p); |
| } |
| } |
| |
| /* |
| * process group orphan check |
| * Case ii: Our child is in a different pgrp |
| * than we are, and it was the only connection |
| * outside, so the child pgrp is now orphaned. |
| */ |
| if ((process_group(p) != process_group(father)) && |
| (process_session(p) == process_session(father))) { |
| int pgrp = process_group(p); |
| |
| if (will_become_orphaned_pgrp(pgrp, NULL) && |
| has_stopped_jobs(pgrp)) { |
| __kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp); |
| __kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp); |
| } |
| } |
| } |
| |
| /* |
| * When we die, we re-parent all our children. |
| * Try to give them to another thread in our thread |
| * group, and if no such member exists, give it to |
| * the child reaper process (ie "init") in our pid |
| * space. |
| */ |
| static void |
| forget_original_parent(struct task_struct *father, struct list_head *to_release) |
| { |
| struct task_struct *p, *reaper = father; |
| struct list_head *_p, *_n; |
| |
| do { |
| reaper = next_thread(reaper); |
| if (reaper == father) { |
| reaper = child_reaper(father); |
| break; |
| } |
| } while (reaper->exit_state); |
| |
| /* |
| * There are only two places where our children can be: |
| * |
| * - in our child list |
| * - in our ptraced child list |
| * |
| * Search them and reparent children. |
| */ |
| list_for_each_safe(_p, _n, &father->children) { |
| int ptrace; |
| p = list_entry(_p, struct task_struct, sibling); |
| |
| ptrace = p->ptrace; |
| |
| /* if father isn't the real parent, then ptrace must be enabled */ |
| BUG_ON(father != p->real_parent && !ptrace); |
| |
| if (father == p->real_parent) { |
| /* reparent with a reaper, real father it's us */ |
| choose_new_parent(p, reaper); |
| reparent_thread(p, father, 0); |
| } else { |
| /* reparent ptraced task to its real parent */ |
| __ptrace_unlink (p); |
| if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 && |
| thread_group_empty(p)) |
| do_notify_parent(p, p->exit_signal); |
| } |
| |
| /* |
| * if the ptraced child is a zombie with exit_signal == -1 |
| * we must collect it before we exit, or it will remain |
| * zombie forever since we prevented it from self-reap itself |
| * while it was being traced by us, to be able to see it in wait4. |
| */ |
| if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1)) |
| list_add(&p->ptrace_list, to_release); |
| } |
| list_for_each_safe(_p, _n, &father->ptrace_children) { |
| p = list_entry(_p, struct task_struct, ptrace_list); |
| choose_new_parent(p, reaper); |
| reparent_thread(p, father, 1); |
| } |
| } |
| |
| /* |
| * Send signals to all our closest relatives so that they know |
| * to properly mourn us.. |
| */ |
| static void exit_notify(struct task_struct *tsk) |
| { |
| int state; |
| struct task_struct *t; |
| struct list_head ptrace_dead, *_p, *_n; |
| |
| if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT) |
| && !thread_group_empty(tsk)) { |
| /* |
| * This occurs when there was a race between our exit |
| * syscall and a group signal choosing us as the one to |
| * wake up. It could be that we are the only thread |
| * alerted to check for pending signals, but another thread |
| * should be woken now to take the signal since we will not. |
| * Now we'll wake all the threads in the group just to make |
| * sure someone gets all the pending signals. |
| */ |
| read_lock(&tasklist_lock); |
| spin_lock_irq(&tsk->sighand->siglock); |
| for (t = next_thread(tsk); t != tsk; t = next_thread(t)) |
| if (!signal_pending(t) && !(t->flags & PF_EXITING)) { |
| recalc_sigpending_tsk(t); |
| if (signal_pending(t)) |
| signal_wake_up(t, 0); |
| } |
| spin_unlock_irq(&tsk->sighand->siglock); |
| read_unlock(&tasklist_lock); |
| } |
| |
| write_lock_irq(&tasklist_lock); |
| |
| /* |
| * This does two things: |
| * |
| * A. Make init inherit all the child processes |
| * B. Check to see if any process groups have become orphaned |
| * as a result of our exiting, and if they have any stopped |
| * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) |
| */ |
| |
| INIT_LIST_HEAD(&ptrace_dead); |
| forget_original_parent(tsk, &ptrace_dead); |
| BUG_ON(!list_empty(&tsk->children)); |
| BUG_ON(!list_empty(&tsk->ptrace_children)); |
| |
| /* |
| * Check to see if any process groups have become orphaned |
| * as a result of our exiting, and if they have any stopped |
| * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) |
| * |
| * Case i: Our father is in a different pgrp than we are |
| * and we were the only connection outside, so our pgrp |
| * is about to become orphaned. |
| */ |
| |
| t = tsk->real_parent; |
| |
| if ((process_group(t) != process_group(tsk)) && |
| (process_session(t) == process_session(tsk)) && |
| will_become_orphaned_pgrp(process_group(tsk), tsk) && |
| has_stopped_jobs(process_group(tsk))) { |
| __kill_pg_info(SIGHUP, SEND_SIG_PRIV, process_group(tsk)); |
| __kill_pg_info(SIGCONT, SEND_SIG_PRIV, process_group(tsk)); |
| } |
| |
| /* Let father know we died |
| * |
| * Thread signals are configurable, but you aren't going to use |
| * that to send signals to arbitary processes. |
| * That stops right now. |
| * |
| * If the parent exec id doesn't match the exec id we saved |
| * when we started then we know the parent has changed security |
| * domain. |
| * |
| * If our self_exec id doesn't match our parent_exec_id then |
| * we have changed execution domain as these two values started |
| * the same after a fork. |
| * |
| */ |
| |
| if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 && |
| ( tsk->parent_exec_id != t->self_exec_id || |
| tsk->self_exec_id != tsk->parent_exec_id) |
| && !capable(CAP_KILL)) |
| tsk->exit_signal = SIGCHLD; |
| |
| |
| /* If something other than our normal parent is ptracing us, then |
| * send it a SIGCHLD instead of honoring exit_signal. exit_signal |
| * only has special meaning to our real parent. |
| */ |
| if (tsk->exit_signal != -1 && thread_group_empty(tsk)) { |
| int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD; |
| do_notify_parent(tsk, signal); |
| } else if (tsk->ptrace) { |
| do_notify_parent(tsk, SIGCHLD); |
| } |
| |
| state = EXIT_ZOMBIE; |
| if (tsk->exit_signal == -1 && |
| (likely(tsk->ptrace == 0) || |
| unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT))) |
| state = EXIT_DEAD; |
| tsk->exit_state = state; |
| |
| write_unlock_irq(&tasklist_lock); |
| |
| list_for_each_safe(_p, _n, &ptrace_dead) { |
| list_del_init(_p); |
| t = list_entry(_p, struct task_struct, ptrace_list); |
| release_task(t); |
| } |
| |
| /* If the process is dead, release it - nobody will wait for it */ |
| if (state == EXIT_DEAD) |
| release_task(tsk); |
| } |
| |
| fastcall NORET_TYPE void do_exit(long code) |
| { |
| struct task_struct *tsk = current; |
| int group_dead; |
| |
| profile_task_exit(tsk); |
| |
| WARN_ON(atomic_read(&tsk->fs_excl)); |
| |
| if (unlikely(in_interrupt())) |
| panic("Aiee, killing interrupt handler!"); |
| if (unlikely(!tsk->pid)) |
| panic("Attempted to kill the idle task!"); |
| if (unlikely(tsk == child_reaper(tsk))) { |
| if (tsk->nsproxy->pid_ns != &init_pid_ns) |
| tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper; |
| else |
| panic("Attempted to kill init!"); |
| } |
| |
| |
| if (unlikely(current->ptrace & PT_TRACE_EXIT)) { |
| current->ptrace_message = code; |
| ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); |
| } |
| |
| /* |
| * We're taking recursive faults here in do_exit. Safest is to just |
| * leave this task alone and wait for reboot. |
| */ |
| if (unlikely(tsk->flags & PF_EXITING)) { |
| printk(KERN_ALERT |
| "Fixing recursive fault but reboot is needed!\n"); |
| if (tsk->io_context) |
| exit_io_context(); |
| set_current_state(TASK_UNINTERRUPTIBLE); |
| schedule(); |
| } |
| |
| tsk->flags |= PF_EXITING; |
| |
| if (unlikely(in_atomic())) |
| printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", |
| current->comm, current->pid, |
| preempt_count()); |
| |
| acct_update_integrals(tsk); |
| if (tsk->mm) { |
| update_hiwater_rss(tsk->mm); |
| update_hiwater_vm(tsk->mm); |
| } |
| group_dead = atomic_dec_and_test(&tsk->signal->live); |
| if (group_dead) { |
| hrtimer_cancel(&tsk->signal->real_timer); |
| exit_itimers(tsk->signal); |
| } |
| acct_collect(code, group_dead); |
| if (unlikely(tsk->robust_list)) |
| exit_robust_list(tsk); |
| #if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT) |
| if (unlikely(tsk->compat_robust_list)) |
| compat_exit_robust_list(tsk); |
| #endif |
| if (unlikely(tsk->audit_context)) |
| audit_free(tsk); |
| |
| taskstats_exit(tsk, group_dead); |
| |
| exit_mm(tsk); |
| |
| if (group_dead) |
| acct_process(); |
| exit_sem(tsk); |
| __exit_files(tsk); |
| __exit_fs(tsk); |
| exit_thread(); |
| cpuset_exit(tsk); |
| exit_keys(tsk); |
| |
| if (group_dead && tsk->signal->leader) |
| disassociate_ctty(1); |
| |
| module_put(task_thread_info(tsk)->exec_domain->module); |
| if (tsk->binfmt) |
| module_put(tsk->binfmt->module); |
| |
| tsk->exit_code = code; |
| proc_exit_connector(tsk); |
| exit_notify(tsk); |
| exit_task_namespaces(tsk); |
| #ifdef CONFIG_NUMA |
| mpol_free(tsk->mempolicy); |
| tsk->mempolicy = NULL; |
| #endif |
| /* |
| * This must happen late, after the PID is not |
| * hashed anymore: |
| */ |
| if (unlikely(!list_empty(&tsk->pi_state_list))) |
| exit_pi_state_list(tsk); |
| if (unlikely(current->pi_state_cache)) |
| kfree(current->pi_state_cache); |
| /* |
| * Make sure we are holding no locks: |
| */ |
| debug_check_no_locks_held(tsk); |
| |
| if (tsk->io_context) |
| exit_io_context(); |
| |
| if (tsk->splice_pipe) |
| __free_pipe_info(tsk->splice_pipe); |
| |
| preempt_disable(); |
| /* causes final put_task_struct in finish_task_switch(). */ |
| tsk->state = TASK_DEAD; |
| |
| schedule(); |
| BUG(); |
| /* Avoid "noreturn function does return". */ |
| for (;;) |
| cpu_relax(); /* For when BUG is null */ |
| } |
| |
| EXPORT_SYMBOL_GPL(do_exit); |
| |
| NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
| { |
| if (comp) |
| complete(comp); |
| |
| do_exit(code); |
| } |
| |
| EXPORT_SYMBOL(complete_and_exit); |
| |
| asmlinkage long sys_exit(int error_code) |
| { |
| do_exit((error_code&0xff)<<8); |
| } |
| |
| /* |
| * Take down every thread in the group. This is called by fatal signals |
| * as well as by sys_exit_group (below). |
| */ |
| NORET_TYPE void |
| do_group_exit(int exit_code) |
| { |
| BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
| |
| if (current->signal->flags & SIGNAL_GROUP_EXIT) |
| exit_code = current->signal->group_exit_code; |
| else if (!thread_group_empty(current)) { |
| struct signal_struct *const sig = current->signal; |
| struct sighand_struct *const sighand = current->sighand; |
| spin_lock_irq(&sighand->siglock); |
| if (sig->flags & SIGNAL_GROUP_EXIT) |
| /* Another thread got here before we took the lock. */ |
| exit_code = sig->group_exit_code; |
| else { |
| sig->group_exit_code = exit_code; |
| zap_other_threads(current); |
| } |
| spin_unlock_irq(&sighand->siglock); |
| } |
| |
| do_exit(exit_code); |
| /* NOTREACHED */ |
| } |
| |
| /* |
| * this kills every thread in the thread group. Note that any externally |
| * wait4()-ing process will get the correct exit code - even if this |
| * thread is not the thread group leader. |
| */ |
| asmlinkage void sys_exit_group(int error_code) |
| { |
| do_group_exit((error_code & 0xff) << 8); |
| } |
| |
| static int eligible_child(pid_t pid, int options, struct task_struct *p) |
| { |
| if (pid > 0) { |
| if (p->pid != pid) |
| return 0; |
| } else if (!pid) { |
| if (process_group(p) != process_group(current)) |
| return 0; |
| } else if (pid != -1) { |
| if (process_group(p) != -pid) |
| return 0; |
| } |
| |
| /* |
| * Do not consider detached threads that are |
| * not ptraced: |
| */ |
| if (p->exit_signal == -1 && !p->ptrace) |
| return 0; |
| |
| /* Wait for all children (clone and not) if __WALL is set; |
| * otherwise, wait for clone children *only* if __WCLONE is |
| * set; otherwise, wait for non-clone children *only*. (Note: |
| * A "clone" child here is one that reports to its parent |
| * using a signal other than SIGCHLD.) */ |
| if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) |
| && !(options & __WALL)) |
| return 0; |
| /* |
| * Do not consider thread group leaders that are |
| * in a non-empty thread group: |
| */ |
| if (delay_group_leader(p)) |
| return 2; |
| |
| if (security_task_wait(p)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
| int why, int status, |
| struct siginfo __user *infop, |
| struct rusage __user *rusagep) |
| { |
| int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; |
| |
| put_task_struct(p); |
| if (!retval) |
| retval = put_user(SIGCHLD, &infop->si_signo); |
| if (!retval) |
| retval = put_user(0, &infop->si_errno); |
| if (!retval) |
| retval = put_user((short)why, &infop->si_code); |
| if (!retval) |
| retval = put_user(pid, &infop->si_pid); |
| if (!retval) |
| retval = put_user(uid, &infop->si_uid); |
| if (!retval) |
| retval = put_user(status, &infop->si_status); |
| if (!retval) |
| retval = pid; |
| return retval; |
| } |
| |
| /* |
| * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold |
| * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| * the lock and this task is uninteresting. If we return nonzero, we have |
| * released the lock and the system call should return. |
| */ |
| static int wait_task_zombie(struct task_struct *p, int noreap, |
| struct siginfo __user *infop, |
| int __user *stat_addr, struct rusage __user *ru) |
| { |
| unsigned long state; |
| int retval; |
| int status; |
| |
| if (unlikely(noreap)) { |
| pid_t pid = p->pid; |
| uid_t uid = p->uid; |
| int exit_code = p->exit_code; |
| int why, status; |
| |
| if (unlikely(p->exit_state != EXIT_ZOMBIE)) |
| return 0; |
| if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) |
| return 0; |
| get_task_struct(p); |
| read_unlock(&tasklist_lock); |
| if ((exit_code & 0x7f) == 0) { |
| why = CLD_EXITED; |
| status = exit_code >> 8; |
| } else { |
| why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; |
| status = exit_code & 0x7f; |
| } |
| return wait_noreap_copyout(p, pid, uid, why, |
| status, infop, ru); |
| } |
| |
| /* |
| * Try to move the task's state to DEAD |
| * only one thread is allowed to do this: |
| */ |
| state = xchg(&p->exit_state, EXIT_DEAD); |
| if (state != EXIT_ZOMBIE) { |
| BUG_ON(state != EXIT_DEAD); |
| return 0; |
| } |
| if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) { |
| /* |
| * This can only happen in a race with a ptraced thread |
| * dying on another processor. |
| */ |
| return 0; |
| } |
| |
| if (likely(p->real_parent == p->parent) && likely(p->signal)) { |
| struct signal_struct *psig; |
| struct signal_struct *sig; |
| |
| /* |
| * The resource counters for the group leader are in its |
| * own task_struct. Those for dead threads in the group |
| * are in its signal_struct, as are those for the child |
| * processes it has previously reaped. All these |
| * accumulate in the parent's signal_struct c* fields. |
| * |
| * We don't bother to take a lock here to protect these |
| * p->signal fields, because they are only touched by |
| * __exit_signal, which runs with tasklist_lock |
| * write-locked anyway, and so is excluded here. We do |
| * need to protect the access to p->parent->signal fields, |
| * as other threads in the parent group can be right |
| * here reaping other children at the same time. |
| */ |
| spin_lock_irq(&p->parent->sighand->siglock); |
| psig = p->parent->signal; |
| sig = p->signal; |
| psig->cutime = |
| cputime_add(psig->cutime, |
| cputime_add(p->utime, |
| cputime_add(sig->utime, |
| sig->cutime))); |
| psig->cstime = |
| cputime_add(psig->cstime, |
| cputime_add(p->stime, |
| cputime_add(sig->stime, |
| sig->cstime))); |
| psig->cmin_flt += |
| p->min_flt + sig->min_flt + sig->cmin_flt; |
| psig->cmaj_flt += |
| p->maj_flt + sig->maj_flt + sig->cmaj_flt; |
| psig->cnvcsw += |
| p->nvcsw + sig->nvcsw + sig->cnvcsw; |
| psig->cnivcsw += |
| p->nivcsw + sig->nivcsw + sig->cnivcsw; |
| spin_unlock_irq(&p->parent->sighand->siglock); |
| } |
| |
| /* |
| * Now we are sure this task is interesting, and no other |
| * thread can reap it because we set its state to EXIT_DEAD. |
| */ |
| read_unlock(&tasklist_lock); |
| |
| retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| status = (p->signal->flags & SIGNAL_GROUP_EXIT) |
| ? p->signal->group_exit_code : p->exit_code; |
| if (!retval && stat_addr) |
| retval = put_user(status, stat_addr); |
| if (!retval && infop) |
| retval = put_user(SIGCHLD, &infop->si_signo); |
| if (!retval && infop) |
| retval = put_user(0, &infop->si_errno); |
| if (!retval && infop) { |
| int why; |
| |
| if ((status & 0x7f) == 0) { |
| why = CLD_EXITED; |
| status >>= 8; |
| } else { |
| why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; |
| status &= 0x7f; |
| } |
| retval = put_user((short)why, &infop->si_code); |
| if (!retval) |
| retval = put_user(status, &infop->si_status); |
| } |
| if (!retval && infop) |
| retval = put_user(p->pid, &infop->si_pid); |
| if (!retval && infop) |
| retval = put_user(p->uid, &infop->si_uid); |
| if (retval) { |
| // TODO: is this safe? |
| p->exit_state = EXIT_ZOMBIE; |
| return retval; |
| } |
| retval = p->pid; |
| if (p->real_parent != p->parent) { |
| write_lock_irq(&tasklist_lock); |
| /* Double-check with lock held. */ |
| if (p->real_parent != p->parent) { |
| __ptrace_unlink(p); |
| // TODO: is this safe? |
| p->exit_state = EXIT_ZOMBIE; |
| /* |
| * If this is not a detached task, notify the parent. |
| * If it's still not detached after that, don't release |
| * it now. |
| */ |
| if (p->exit_signal != -1) { |
| do_notify_parent(p, p->exit_signal); |
| if (p->exit_signal != -1) |
| p = NULL; |
| } |
| } |
| write_unlock_irq(&tasklist_lock); |
| } |
| if (p != NULL) |
| release_task(p); |
| BUG_ON(!retval); |
| return retval; |
| } |
| |
| /* |
| * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold |
| * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| * the lock and this task is uninteresting. If we return nonzero, we have |
| * released the lock and the system call should return. |
| */ |
| static int wait_task_stopped(struct task_struct *p, int delayed_group_leader, |
| int noreap, struct siginfo __user *infop, |
| int __user *stat_addr, struct rusage __user *ru) |
| { |
| int retval, exit_code; |
| |
| if (!p->exit_code) |
| return 0; |
| if (delayed_group_leader && !(p->ptrace & PT_PTRACED) && |
| p->signal && p->signal->group_stop_count > 0) |
| /* |
| * A group stop is in progress and this is the group leader. |
| * We won't report until all threads have stopped. |
| */ |
| return 0; |
| |
| /* |
| * Now we are pretty sure this task is interesting. |
| * Make sure it doesn't get reaped out from under us while we |
| * give up the lock and then examine it below. We don't want to |
| * keep holding onto the tasklist_lock while we call getrusage and |
| * possibly take page faults for user memory. |
| */ |
| get_task_struct(p); |
| read_unlock(&tasklist_lock); |
| |
| if (unlikely(noreap)) { |
| pid_t pid = p->pid; |
| uid_t uid = p->uid; |
| int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; |
| |
| exit_code = p->exit_code; |
| if (unlikely(!exit_code) || |
| unlikely(p->state & TASK_TRACED)) |
| goto bail_ref; |
| return wait_noreap_copyout(p, pid, uid, |
| why, (exit_code << 8) | 0x7f, |
| infop, ru); |
| } |
| |
| write_lock_irq(&tasklist_lock); |
| |
| /* |
| * This uses xchg to be atomic with the thread resuming and setting |
| * it. It must also be done with the write lock held to prevent a |
| * race with the EXIT_ZOMBIE case. |
| */ |
| exit_code = xchg(&p->exit_code, 0); |
| if (unlikely(p->exit_state)) { |
| /* |
| * The task resumed and then died. Let the next iteration |
| * catch it in EXIT_ZOMBIE. Note that exit_code might |
| * already be zero here if it resumed and did _exit(0). |
| * The task itself is dead and won't touch exit_code again; |
| * other processors in this function are locked out. |
| */ |
| p->exit_code = exit_code; |
| exit_code = 0; |
| } |
| if (unlikely(exit_code == 0)) { |
| /* |
| * Another thread in this function got to it first, or it |
| * resumed, or it resumed and then died. |
| */ |
| write_unlock_irq(&tasklist_lock); |
| bail_ref: |
| put_task_struct(p); |
| /* |
| * We are returning to the wait loop without having successfully |
| * removed the process and having released the lock. We cannot |
| * continue, since the "p" task pointer is potentially stale. |
| * |
| * Return -EAGAIN, and do_wait() will restart the loop from the |
| * beginning. Do _not_ re-acquire the lock. |
| */ |
| return -EAGAIN; |
| } |
| |
| /* move to end of parent's list to avoid starvation */ |
| remove_parent(p); |
| add_parent(p); |
| |
| write_unlock_irq(&tasklist_lock); |
| |
| retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| if (!retval && stat_addr) |
| retval = put_user((exit_code << 8) | 0x7f, stat_addr); |
| if (!retval && infop) |
| retval = put_user(SIGCHLD, &infop->si_signo); |
| if (!retval && infop) |
| retval = put_user(0, &infop->si_errno); |
| if (!retval && infop) |
| retval = put_user((short)((p->ptrace & PT_PTRACED) |
| ? CLD_TRAPPED : CLD_STOPPED), |
| &infop->si_code); |
| if (!retval && infop) |
| retval = put_user(exit_code, &infop->si_status); |
| if (!retval && infop) |
| retval = put_user(p->pid, &infop->si_pid); |
| if (!retval && infop) |
| retval = put_user(p->uid, &infop->si_uid); |
| if (!retval) |
| retval = p->pid; |
| put_task_struct(p); |
| |
| BUG_ON(!retval); |
| return retval; |
| } |
| |
| /* |
| * Handle do_wait work for one task in a live, non-stopped state. |
| * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| * the lock and this task is uninteresting. If we return nonzero, we have |
| * released the lock and the system call should return. |
| */ |
| static int wait_task_continued(struct task_struct *p, int noreap, |
| struct siginfo __user *infop, |
| int __user *stat_addr, struct rusage __user *ru) |
| { |
| int retval; |
| pid_t pid; |
| uid_t uid; |
| |
| if (unlikely(!p->signal)) |
| return 0; |
| |
| if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
| return 0; |
| |
| spin_lock_irq(&p->sighand->siglock); |
| /* Re-check with the lock held. */ |
| if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { |
| spin_unlock_irq(&p->sighand->siglock); |
| return 0; |
| } |
| if (!noreap) |
| p->signal->flags &= ~SIGNAL_STOP_CONTINUED; |
| spin_unlock_irq(&p->sighand->siglock); |
| |
| pid = p->pid; |
| uid = p->uid; |
| get_task_struct(p); |
| read_unlock(&tasklist_lock); |
| |
| if (!infop) { |
| retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| put_task_struct(p); |
| if (!retval && stat_addr) |
| retval = put_user(0xffff, stat_addr); |
| if (!retval) |
| retval = p->pid; |
| } else { |
| retval = wait_noreap_copyout(p, pid, uid, |
| CLD_CONTINUED, SIGCONT, |
| infop, ru); |
| BUG_ON(retval == 0); |
| } |
| |
| return retval; |
| } |
| |
| |
| static inline int my_ptrace_child(struct task_struct *p) |
| { |
| if (!(p->ptrace & PT_PTRACED)) |
| return 0; |
| if (!(p->ptrace & PT_ATTACHED)) |
| return 1; |
| /* |
| * This child was PTRACE_ATTACH'd. We should be seeing it only if |
| * we are the attacher. If we are the real parent, this is a race |
| * inside ptrace_attach. It is waiting for the tasklist_lock, |
| * which we have to switch the parent links, but has already set |
| * the flags in p->ptrace. |
| */ |
| return (p->parent != p->real_parent); |
| } |
| |
| static long do_wait(pid_t pid, int options, struct siginfo __user *infop, |
| int __user *stat_addr, struct rusage __user *ru) |
| { |
| DECLARE_WAITQUEUE(wait, current); |
| struct task_struct *tsk; |
| int flag, retval; |
| |
| add_wait_queue(¤t->signal->wait_chldexit,&wait); |
| repeat: |
| /* |
| * We will set this flag if we see any child that might later |
| * match our criteria, even if we are not able to reap it yet. |
| */ |
| flag = 0; |
| current->state = TASK_INTERRUPTIBLE; |
| read_lock(&tasklist_lock); |
| tsk = current; |
| do { |
| struct task_struct *p; |
| struct list_head *_p; |
| int ret; |
| |
| list_for_each(_p,&tsk->children) { |
| p = list_entry(_p, struct task_struct, sibling); |
| |
| ret = eligible_child(pid, options, p); |
| if (!ret) |
| continue; |
| |
| switch (p->state) { |
| case TASK_TRACED: |
| /* |
| * When we hit the race with PTRACE_ATTACH, |
| * we will not report this child. But the |
| * race means it has not yet been moved to |
| * our ptrace_children list, so we need to |
| * set the flag here to avoid a spurious ECHILD |
| * when the race happens with the only child. |
| */ |
| flag = 1; |
| if (!my_ptrace_child(p)) |
| continue; |
| /*FALLTHROUGH*/ |
| case TASK_STOPPED: |
| /* |
| * It's stopped now, so it might later |
| * continue, exit, or stop again. |
| */ |
| flag = 1; |
| if (!(options & WUNTRACED) && |
| !my_ptrace_child(p)) |
| continue; |
| retval = wait_task_stopped(p, ret == 2, |
| (options & WNOWAIT), |
| infop, |
| stat_addr, ru); |
| if (retval == -EAGAIN) |
| goto repeat; |
| if (retval != 0) /* He released the lock. */ |
| goto end; |
| break; |
| default: |
| // case EXIT_DEAD: |
| if (p->exit_state == EXIT_DEAD) |
| continue; |
| // case EXIT_ZOMBIE: |
| if (p->exit_state == EXIT_ZOMBIE) { |
| /* |
| * Eligible but we cannot release |
| * it yet: |
| */ |
| if (ret == 2) |
| goto check_continued; |
| if (!likely(options & WEXITED)) |
| continue; |
| retval = wait_task_zombie( |
| p, (options & WNOWAIT), |
| infop, stat_addr, ru); |
| /* He released the lock. */ |
| if (retval != 0) |
| goto end; |
| break; |
| } |
| check_continued: |
| /* |
| * It's running now, so it might later |
| * exit, stop, or stop and then continue. |
| */ |
| flag = 1; |
| if (!unlikely(options & WCONTINUED)) |
| continue; |
| retval = wait_task_continued( |
| p, (options & WNOWAIT), |
| infop, stat_addr, ru); |
| if (retval != 0) /* He released the lock. */ |
| goto end; |
| break; |
| } |
| } |
| if (!flag) { |
| list_for_each(_p, &tsk->ptrace_children) { |
| p = list_entry(_p, struct task_struct, |
| ptrace_list); |
| if (!eligible_child(pid, options, p)) |
| continue; |
| flag = 1; |
| break; |
| } |
| } |
| if (options & __WNOTHREAD) |
| break; |
| tsk = next_thread(tsk); |
| BUG_ON(tsk->signal != current->signal); |
| } while (tsk != current); |
| |
| read_unlock(&tasklist_lock); |
| if (flag) { |
| retval = 0; |
| if (options & WNOHANG) |
| goto end; |
| retval = -ERESTARTSYS; |
| if (signal_pending(current)) |
| goto end; |
| schedule(); |
| goto repeat; |
| } |
| retval = -ECHILD; |
| end: |
| current->state = TASK_RUNNING; |
| remove_wait_queue(¤t->signal->wait_chldexit,&wait); |
| if (infop) { |
| if (retval > 0) |
| retval = 0; |
| else { |
| /* |
| * For a WNOHANG return, clear out all the fields |
| * we would set so the user can easily tell the |
| * difference. |
| */ |
| if (!retval) |
| retval = put_user(0, &infop->si_signo); |
| if (!retval) |
| retval = put_user(0, &infop->si_errno); |
| if (!retval) |
| retval = put_user(0, &infop->si_code); |
| if (!retval) |
| retval = put_user(0, &infop->si_pid); |
| if (!retval) |
| retval = put_user(0, &infop->si_uid); |
| if (!retval) |
| retval = put_user(0, &infop->si_status); |
| } |
| } |
| return retval; |
| } |
| |
| asmlinkage long sys_waitid(int which, pid_t pid, |
| struct siginfo __user *infop, int options, |
| struct rusage __user *ru) |
| { |
| long ret; |
| |
| if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) |
| return -EINVAL; |
| if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) |
| return -EINVAL; |
| |
| switch (which) { |
| case P_ALL: |
| pid = -1; |
| break; |
| case P_PID: |
| if (pid <= 0) |
| return -EINVAL; |
| break; |
| case P_PGID: |
| if (pid <= 0) |
| return -EINVAL; |
| pid = -pid; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| ret = do_wait(pid, options, infop, NULL, ru); |
| |
| /* avoid REGPARM breakage on x86: */ |
| prevent_tail_call(ret); |
| return ret; |
| } |
| |
| asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr, |
| int options, struct rusage __user *ru) |
| { |
| long ret; |
| |
| if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| |
| __WNOTHREAD|__WCLONE|__WALL)) |
| return -EINVAL; |
| ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru); |
| |
| /* avoid REGPARM breakage on x86: */ |
| prevent_tail_call(ret); |
| return ret; |
| } |
| |
| #ifdef __ARCH_WANT_SYS_WAITPID |
| |
| /* |
| * sys_waitpid() remains for compatibility. waitpid() should be |
| * implemented by calling sys_wait4() from libc.a. |
| */ |
| asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) |
| { |
| return sys_wait4(pid, stat_addr, options, NULL); |
| } |
| |
| #endif |