X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fexit.c;h=29617024d245a36b90e0f1399366485e3594d74b;hb=refs%2Fheads%2Fvserver;hp=208cbfa0987723699534ede7b6786ea111b0c53a;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/kernel/exit.c b/kernel/exit.c index 208cbfa09..29617024d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -4,7 +4,6 @@ * Copyright (C) 1991, 1992 Linus Torvalds */ -#include #include #include #include @@ -14,27 +13,41 @@ #include #include #include -#include +#include #include #include #include #include +#include #include #include +#include +#include +#include #include #include #include #include #include +#include +#include #include #include #include +#include #include #include +#include +#include +#include +#include /* for audit_free() */ +#include +#include #include #include #include -#include +#include +#include #include #include @@ -42,9 +55,6 @@ #include extern void sem_exit (void); -extern struct task_struct *child_reaper; - -int getrusage(struct task_struct *, int, struct rusage __user *); static void exit_mm(struct task_struct * tsk); @@ -52,38 +62,99 @@ static void __unhash_process(struct task_struct *p) { nr_threads--; detach_pid(p, PIDTYPE_PID); - detach_pid(p, PIDTYPE_TGID); if (thread_group_leader(p)) { detach_pid(p, PIDTYPE_PGID); detach_pid(p, PIDTYPE_SID); - if (p->pid) - __get_cpu_var(process_counts)--; + + 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. */ } - REMOVE_LINKS(p); + __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; - task_t *leader; - struct dentry *proc_dentry; - -repeat: + int inhibited_leader; +repeat: + tracehook_release_task(p); atomic_dec(&p->user->processes); - spin_lock(&p->proc_lock); - proc_dentry = proc_pid_unhash(p); write_lock_irq(&tasklist_lock); - if (unlikely(p->ptrace)) - __ptrace_unlink(p); - BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); + BUG_ON(tracehook_check_released(p)); __exit_signal(p); - /* - * Note that the fastpath in sys_times depends on __exit_signal having - * updated the counters before a task is removed from the tasklist of - * the process by __unhash_process. - */ - __unhash_process(p); /* * If we are the last non-leader member of the thread @@ -91,10 +162,14 @@ repeat: * group leader's parent process. (if it wants notification.) */ zap_leader = 0; + inhibited_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 (tracehook_inhibit_wait_zombie(leader)) + inhibited_leader = 1; + else + 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, @@ -108,29 +183,20 @@ repeat: sched_exit(p); write_unlock_irq(&tasklist_lock); - spin_unlock(&p->proc_lock); - proc_pid_flush(proc_dentry); + proc_flush_task(p); release_thread(p); - put_task_struct(p); + call_rcu(&p->rcu, delayed_put_task_struct); p = leader; if (unlikely(zap_leader)) goto repeat; -} -/* we are using it only for SMP init */ - -void unhash_process(struct task_struct *p) -{ - struct dentry *proc_dentry; - - spin_lock(&p->proc_lock); - proc_dentry = proc_pid_unhash(p); - write_lock_irq(&tasklist_lock); - __unhash_process(p); - write_unlock_irq(&tasklist_lock); - spin_unlock(&p->proc_lock); - proc_pid_flush(proc_dentry); + /* + * If tracing usurps normal reaping of the leader, tracing needs + * to be notified it would normally be reapable now. + */ + if (unlikely(inhibited_leader)) + tracehook_report_delayed_group_leader(leader); } /* @@ -141,21 +207,18 @@ void unhash_process(struct task_struct *p) int session_of_pgrp(int pgrp) { struct task_struct *p; - int sid = -1; + int sid = 0; read_lock(&tasklist_lock); - do_each_task_pid(pgrp, PIDTYPE_PGID, p) { - if (p->signal->session > 0) { - sid = p->signal->session; - goto out; - } - } while_each_task_pid(pgrp, PIDTYPE_PGID, p); - p = find_task_by_pid(pgrp); - if (p) - sid = p->signal->session; -out: + + 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; } @@ -167,7 +230,7 @@ out: * * "I ask you, have you ever known what it is to be an orphan?" */ -static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task) +static int will_become_orphaned_pgrp(int pgrp, struct task_struct *ignored_task) { struct task_struct *p; int ret = 1; @@ -175,10 +238,10 @@ static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task) do_each_task_pid(pgrp, PIDTYPE_PGID, p) { if (p == ignored_task || p->exit_state - || p->real_parent->pid == 1) + || is_init(p->parent)) continue; - if (process_group(p->real_parent) != pgrp - && p->real_parent->signal->session == p->signal->session) { + if (process_group(p->parent) != pgrp && + process_session(p->parent) == process_session(p)) { ret = 0; break; } @@ -205,17 +268,6 @@ static int has_stopped_jobs(int pgrp) do_each_task_pid(pgrp, PIDTYPE_PGID, p) { if (p->state != TASK_STOPPED) continue; - - /* If p is stopped by a debugger on a signal that won't - stop it, then don't count p as stopped. This isn't - perfect but it's a good approximation. */ - if (unlikely (p->ptrace) - && p->exit_code != SIGSTOP - && p->exit_code != SIGTSTP - && p->exit_code != SIGTTOU - && p->exit_code != SIGTTIN) - continue; - retval = 1; break; } while_each_task_pid(pgrp, PIDTYPE_PGID, p); @@ -223,7 +275,8 @@ static int has_stopped_jobs(int pgrp) } /** - * reparent_to_init - Reparent the calling kernel thread to the init task. + * 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 @@ -238,19 +291,15 @@ static void reparent_to_init(void) { write_lock_irq(&tasklist_lock); - ptrace_unlink(current); /* Reparent to init */ - REMOVE_LINKS(current); - current->parent = child_reaper; - current->real_parent = child_reaper; - SET_LINKS(current); + remove_parent(current); + current->parent = child_reaper(current); + add_parent(current); /* Set the exit signal to SIGCHLD so we signal init on exit */ current->exit_signal = SIGCHLD; - if ((current->policy == SCHED_NORMAL || - current->policy == SCHED_BATCH) - && (task_nice(current) < 0)) + if (!has_rt_policy(current) && (task_nice(current) < 0)) set_user_nice(current, 0); /* cpus_allowed? */ /* rt_priority? */ @@ -267,9 +316,9 @@ void __set_special_pids(pid_t session, pid_t pgrp) { struct task_struct *curr = current->group_leader; - if (curr->signal->session != session) { + if (process_session(curr) != session) { detach_pid(curr, PIDTYPE_SID); - curr->signal->session = session; + set_signal_session(curr->signal, session); attach_pid(curr, PIDTYPE_SID, session); } if (process_group(curr) != pgrp) { @@ -279,7 +328,7 @@ void __set_special_pids(pid_t session, pid_t pgrp) } } -void set_special_pids(pid_t session, pid_t pgrp) +static void set_special_pids(pid_t session, pid_t pgrp) { write_lock_irq(&tasklist_lock); __set_special_pids(session, pgrp); @@ -349,9 +398,7 @@ void daemonize(const char *name, ...) exit_mm(current); set_special_pids(1, 1); - down(&tty_sem); - current->signal->tty = NULL; - up(&tty_sem); + proc_clear_tty(current); /* Block and flush all signals */ sigfillset(&blocked); @@ -364,9 +411,11 @@ void daemonize(const char *name, ...) fs = init_task.fs; current->fs = fs; atomic_inc(&fs->count); - exit_namespace(current); - current->namespace = init_task.namespace; - get_namespace(current->namespace); + + 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); @@ -392,7 +441,7 @@ static void close_files(struct files_struct * files) for (;;) { unsigned long set; i = j * __NFDBITS; - if (i >= fdt->max_fdset || i >= fdt->max_fds) + if (i >= fdt->max_fds) break; set = fdt->open_fds->fds_bits[j++]; while (set) { @@ -404,6 +453,7 @@ static void close_files(struct files_struct * files) } i++; set >>= 1; + cond_resched(); } } } @@ -434,9 +484,7 @@ void fastcall put_files_struct(struct files_struct *files) * you can free files immediately. */ fdt = files_fdtable(files); - if (fdt == &files->fdtab) - fdt->free_files = files; - else + if (fdt != &files->fdtab) kmem_cache_free(files_cachep, files); free_fdtable(fdt); } @@ -444,6 +492,18 @@ void fastcall put_files_struct(struct files_struct *files) 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; @@ -473,6 +533,7 @@ static inline void __put_fs_struct(struct fs_struct *fs) dput(fs->altroot); mntput(fs->altrootmnt); } + atomic_dec(&vs_global_fs); kmem_cache_free(fs_cachep, fs); } } @@ -531,7 +592,7 @@ static void exit_mm(struct task_struct * tsk) down_read(&mm->mmap_sem); } atomic_inc(&mm->mm_count); - if (mm != tsk->active_mm) BUG(); + BUG_ON(mm != tsk->active_mm); /* more a memory barrier than a real lock */ task_lock(tsk); tsk->mm = NULL; @@ -541,61 +602,52 @@ static void exit_mm(struct task_struct * tsk) mmput(mm); } -static inline void choose_new_parent(task_t *p, task_t *reaper) +static inline void +choose_new_parent(struct task_struct *p, struct task_struct *reaper) { /* check for reaper context */ - vxwprintk((p->xid != reaper->xid) && (reaper != child_reaper), + vxwprintk((p->xid != reaper->xid) && (reaper != child_reaper(p)), "rogue reaper: %p[%d,#%u] <> %p[%d,#%u]", p, p->pid, p->xid, reaper, reaper->pid, reaper->xid); + if (p == reaper) + reaper = vx_child_reaper(p); + /* * Make sure we're not reparenting to ourselves and that * the parent is not a zombie. */ - BUG_ON(p == reaper || reaper->exit_state >= EXIT_ZOMBIE); - p->real_parent = reaper; + BUG_ON(p == reaper || reaper->exit_state); + p->parent = reaper; } -static void reparent_thread(task_t *p, task_t *father, int traced) +static void +reparent_thread(struct task_struct *p, struct task_struct *father) { - /* 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; - list_del_init(&p->sibling); - p->parent = p->real_parent; - list_add_tail(&p->sibling, &p->parent->children); + list_move_tail(&p->sibling, &p->parent->children); - /* 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); - } - } + /* If this is a threaded reparent there is no need to + * notify anyone anything has happened. + */ + if (p->parent->group_leader == father->group_leader) + return; + + /* We don't want people slaying init. */ + if (p->exit_signal != -1) + p->exit_signal = SIGCHLD; + + /* If we'd notified the old parent about this child's death, + * also notify the new parent. + */ + if (!tracehook_inhibit_wait_zombie(p) && + p->exit_state == EXIT_ZOMBIE && + p->exit_signal != -1 && thread_group_empty(p)) + do_notify_parent(p, p->exit_signal); /* * process group orphan check @@ -604,10 +656,11 @@ static void reparent_thread(task_t *p, task_t *father, int traced) * outside, so the child pgrp is now orphaned. */ if ((process_group(p) != process_group(father)) && - (p->signal->session == father->signal->session)) { + (process_session(p) == process_session(father))) { int pgrp = process_group(p); - if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) { + 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); } @@ -618,10 +671,11 @@ static void reparent_thread(task_t *p, task_t *father, int traced) * 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 global child reaper process (ie "init") + * the child reaper process (ie "init") in our pid + * space. */ -static void forget_original_parent(struct task_struct * father, - struct list_head *to_release) +static void +forget_original_parent(struct task_struct *father) { struct task_struct *p, *reaper = father; struct list_head *_p, *_n; @@ -629,54 +683,16 @@ static void forget_original_parent(struct task_struct * father, do { reaper = next_thread(reaper); if (reaper == father) { + // reaper = child_reaper(father); reaper = vx_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, vx_child_reaper(p)); - 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); - + p = list_entry(_p, struct task_struct, sibling); choose_new_parent(p, reaper); - reparent_thread(p, father, 1); + reparent_thread(p, father); } } @@ -688,7 +704,8 @@ static void exit_notify(struct task_struct *tsk) { int state; struct task_struct *t; - struct list_head ptrace_dead, *_p, *_n; + int noreap; + void *cookie; if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT) && !thread_group_empty(tsk)) { @@ -724,10 +741,8 @@ static void exit_notify(struct task_struct *tsk) * 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); + forget_original_parent(tsk); BUG_ON(!list_empty(&tsk->children)); - BUG_ON(!list_empty(&tsk->ptrace_children)); /* * Check to see if any process groups have become orphaned @@ -739,10 +754,10 @@ static void exit_notify(struct task_struct *tsk) * is about to become orphaned. */ - t = tsk->real_parent; + t = tsk->parent; if ((process_group(t) != process_group(tsk)) && - (t->signal->session == tsk->signal->session) && + (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)); @@ -771,32 +786,18 @@ static void exit_notify(struct task_struct *tsk) && !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); - } + if (!tracehook_notify_death(tsk, &noreap, &cookie) + && tsk->exit_signal != -1 && thread_group_empty(tsk)) + do_notify_parent(tsk, tsk->exit_signal); state = EXIT_ZOMBIE; - if (tsk->exit_signal == -1 && - (likely(tsk->ptrace == 0) || - unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT))) + if (tsk->exit_signal == -1 && !noreap) 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); - } + tracehook_report_death(tsk, state, cookie); /* If the process is dead, release it - nobody will wait for it */ if (state == EXIT_DEAD) @@ -816,16 +817,16 @@ fastcall NORET_TYPE void do_exit(long code) panic("Aiee, killing interrupt handler!"); if (unlikely(!tsk->pid)) panic("Attempted to kill the idle task!"); - if (unlikely(tsk->pid == 1)) - panic("Attempted to kill init!"); - if (tsk->io_context) - exit_io_context(); - - if (unlikely(current->ptrace & PT_TRACE_EXIT)) { - current->ptrace_message = code; - ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); + 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!"); } + + tracehook_report_exit(&code); + /* * We're taking recursive faults here in do_exit. Safest is to just * leave this task alone and wait for reboot. @@ -833,12 +834,16 @@ fastcall NORET_TYPE void do_exit(long code) 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; + ptrace_exit(tsk); + if (unlikely(in_atomic())) printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", current->comm, current->pid, @@ -853,14 +858,26 @@ fastcall NORET_TYPE void do_exit(long code) if (group_dead) { hrtimer_cancel(&tsk->signal->real_timer); exit_itimers(tsk->signal); - acct_process(code); } + 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_namespace(tsk); exit_thread(); cpuset_exit(tsk); exit_keys(tsk); @@ -874,31 +891,48 @@ fastcall NORET_TYPE void do_exit(long code) tsk->exit_code = code; proc_exit_connector(tsk); + exit_task_namespaces(tsk); + // ns = exit_task_namespaces_early(tsk); /* needs to stay before exit_notify() */ exit_vx_info_early(tsk, code); exit_notify(tsk); + // exit_task_namespaces(tsk, ns); #ifdef CONFIG_NUMA mpol_free(tsk->mempolicy); tsk->mempolicy = NULL; #endif /* - * If DEBUG_MUTEXES is on, make sure we are holding no locks: + * This must happen late, after the PID is not + * hashed anymore: */ - mutex_debug_check_no_locks_held(tsk); + 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); /* needs to stay after exit_notify() */ exit_vx_info(tsk, code); exit_nx_info(tsk); - /* PF_DEAD causes final put_task_struct after we schedule. */ preempt_disable(); - BUG_ON(tsk->flags & PF_DEAD); - tsk->flags |= PF_DEAD; + /* causes final put_task_struct in finish_task_switch(). */ + tsk->state = TASK_DEAD; schedule(); BUG(); /* Avoid "noreturn function does return". */ - for (;;) ; + for (;;) + cpu_relax(); /* For when BUG is null */ } EXPORT_SYMBOL_GPL(do_exit); @@ -907,7 +941,7 @@ NORET_TYPE void complete_and_exit(struct completion *comp, long code) { if (comp) complete(comp); - + do_exit(code); } @@ -918,13 +952,6 @@ asmlinkage long sys_exit(int error_code) do_exit((error_code&0xff)<<8); } -task_t fastcall *next_thread(const task_t *p) -{ - return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID); -} - -EXPORT_SYMBOL(next_thread); - /* * Take down every thread in the group. This is called by fatal signals * as well as by sys_exit_group (below). @@ -939,7 +966,6 @@ do_group_exit(int exit_code) else if (!thread_group_empty(current)) { struct signal_struct *const sig = current->signal; struct sighand_struct *const sighand = current->sighand; - read_lock(&tasklist_lock); spin_lock_irq(&sighand->siglock); if (sig->flags & SIGNAL_GROUP_EXIT) /* Another thread got here before we took the lock. */ @@ -949,7 +975,6 @@ do_group_exit(int exit_code) zap_other_threads(current); } spin_unlock_irq(&sighand->siglock); - read_unlock(&tasklist_lock); } do_exit(exit_code); @@ -966,7 +991,7 @@ asmlinkage void sys_exit_group(int error_code) do_group_exit((error_code & 0xff) << 8); } -static int eligible_child(pid_t pid, int options, task_t *p) +static int eligible_child(pid_t pid, int options, struct task_struct *p) { if (pid > 0) { if (p->pid != pid) @@ -980,10 +1005,9 @@ static int eligible_child(pid_t pid, int options, task_t *p) } /* - * Do not consider detached threads that are - * not ptraced: + * Do not consider detached threads. */ - if (p->exit_signal == -1 && !p->ptrace) + if (p->exit_signal == -1) return 0; /* Wait for all children (clone and not) if __WALL is set; @@ -998,7 +1022,7 @@ static int eligible_child(pid_t pid, int options, task_t *p) * Do not consider thread group leaders that are * in a non-empty thread group: */ - if (current->tgid != p->tgid && delay_group_leader(p)) + if (delay_group_leader(p)) return 2; if (security_task_wait(p)) @@ -1007,12 +1031,13 @@ static int eligible_child(pid_t pid, int options, task_t *p) return 1; } -static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid, +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); @@ -1037,7 +1062,7 @@ static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid, * 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(task_t *p, int noreap, +static int wait_task_zombie(struct task_struct *p, int noreap, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { @@ -1053,7 +1078,7 @@ static int wait_task_zombie(task_t *p, int noreap, if (unlikely(p->exit_state != EXIT_ZOMBIE)) return 0; - if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) + if (unlikely(p->exit_signal == -1)) return 0; get_task_struct(p); read_unlock(&tasklist_lock); @@ -1077,15 +1102,9 @@ static int wait_task_zombie(task_t *p, int noreap, 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; - } + BUG_ON(p->exit_signal == -1); - if (likely(p->real_parent == p->parent) && likely(p->signal)) { + if (likely(p->signal)) { struct signal_struct *psig; struct signal_struct *sig; @@ -1167,28 +1186,8 @@ static int wait_task_zombie(task_t *p, int noreap, 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); + release_task(p); + BUG_ON(!retval); return retval; } @@ -1199,15 +1198,15 @@ static int wait_task_zombie(task_t *p, int noreap, * 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(task_t *p, int delayed_group_leader, int noreap, - struct siginfo __user *infop, +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) && + if (delayed_group_leader && p->signal && p->signal->group_stop_count > 0) /* * A group stop is in progress and this is the group leader. @@ -1228,14 +1227,13 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader, int noreap, 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, + return wait_noreap_copyout(p, pid, uid, CLD_STOPPED, + (exit_code << 8) | 0x7f, infop, ru); } @@ -1279,7 +1277,7 @@ bail_ref: /* move to end of parent's list to avoid starvation */ remove_parent(p); - add_parent(p, p->parent); + add_parent(p); write_unlock_irq(&tasklist_lock); @@ -1291,9 +1289,7 @@ bail_ref: 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); + retval = put_user((short)CLD_STOPPED, &infop->si_code); if (!retval && infop) retval = put_user(exit_code, &infop->si_status); if (!retval && infop) @@ -1314,7 +1310,7 @@ bail_ref: * 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(task_t *p, int noreap, +static int wait_task_continued(struct task_struct *p, int noreap, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { @@ -1361,22 +1357,6 @@ static int wait_task_continued(task_t *p, int noreap, } -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) { @@ -1400,7 +1380,7 @@ repeat: int ret; list_for_each(_p,&tsk->children) { - p = list_entry(_p,struct task_struct,sibling); + p = list_entry(_p, struct task_struct, sibling); ret = eligible_child(pid, options, p); if (!ret) @@ -1408,26 +1388,17 @@ repeat: 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*/ + continue; 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)) + if (!(options & WUNTRACED)) + continue; + if (tracehook_inhibit_wait_stopped(p)) continue; retval = wait_task_stopped(p, ret == 2, (options & WNOWAIT), @@ -1452,6 +1423,10 @@ repeat: goto check_continued; if (!likely(options & WEXITED)) continue; + if (tracehook_inhibit_wait_zombie(p)) { + flag = 1; + continue; + } retval = wait_task_zombie( p, (options & WNOWAIT), infop, stat_addr, ru); @@ -1468,6 +1443,8 @@ check_continued: flag = 1; if (!unlikely(options & WCONTINUED)) continue; + if (tracehook_inhibit_wait_continued(p)) + continue; retval = wait_task_continued( p, (options & WNOWAIT), infop, stat_addr, ru); @@ -1476,21 +1453,19 @@ check_continued: 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; - } + + retval = ptrace_do_wait(tsk, pid, options, + infop, stat_addr, ru); + if (retval != -ECHILD) { + flag = 1; + if (retval != 0) /* He released the lock. */ + goto end; } + if (options & __WNOTHREAD) break; tsk = next_thread(tsk); - if (tsk->signal != current->signal) - BUG(); + BUG_ON(tsk->signal != current->signal); } while (tsk != current); read_unlock(&tasklist_lock); @@ -1510,7 +1485,7 @@ end: remove_wait_queue(¤t->signal->wait_chldexit,&wait); if (infop) { if (retval > 0) - retval = 0; + retval = 0; else { /* * For a WNOHANG return, clear out all the fields