X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fexit.c;h=c189de2927ab6b55ab47baf199d347d65481e906;hb=7b0de42d7c5a471741ede4e71727d88000e6ea59;hp=531aadca553030543b643a0553f6144785d02bb5;hpb=5914811acf36c3ff091f860a6964808f668f27d0;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/exit.c b/kernel/exit.c index 531aadc..c189de2 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -4,7 +4,6 @@ * Copyright (C) 1991, 1992 Linus Torvalds */ -#include #include #include #include @@ -26,11 +25,20 @@ #include #include #include +#include +#include #include #include #include +#include #include #include +#include +#include +#include +#include /* for audit_free() */ +#include +#include #include #include @@ -40,46 +48,103 @@ 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); 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); + __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: +repeat: 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); + ptrace_unlink(p); BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); __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 @@ -104,31 +169,15 @@ 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); -} - /* * 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 @@ -163,7 +212,7 @@ 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; @@ -171,7 +220,7 @@ 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->real_parent)) continue; if (process_group(p->real_parent) != pgrp && p->real_parent->signal->session == p->signal->session) { @@ -201,17 +250,6 @@ 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); @@ -236,17 +274,15 @@ static void reparent_to_init(void) ptrace_unlink(current); /* Reparent to init */ - REMOVE_LINKS(current); + remove_parent(current); current->parent = child_reaper; current->real_parent = child_reaper; - SET_LINKS(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? */ @@ -345,9 +381,9 @@ void daemonize(const char *name, ...) exit_mm(current); set_special_pids(1, 1); - down(&tty_sem); + mutex_lock(&tty_mutex); current->signal->tty = NULL; - up(&tty_sem); + mutex_unlock(&tty_mutex); /* Block and flush all signals */ sigfillset(&blocked); @@ -439,6 +475,18 @@ 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; @@ -526,7 +574,7 @@ 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; @@ -536,17 +584,19 @@ static void exit_mm(struct task_struct * tsk) mmput(mm); } -static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_reaper) +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 >= EXIT_ZOMBIE); + BUG_ON(p == reaper || reaper->exit_state); p->real_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, int traced) { /* We don't want people slaying init. */ if (p->exit_signal != -1) @@ -567,9 +617,9 @@ static void reparent_thread(task_t *p, task_t *father, int traced) * anyway, so let go of it. */ p->ptrace = 0; - list_del_init(&p->sibling); + remove_parent(p); p->parent = p->real_parent; - list_add_tail(&p->sibling, &p->parent->children); + add_parent(p); /* If we'd notified the old parent about this child's death, * also notify the new parent. @@ -610,8 +660,8 @@ static void reparent_thread(task_t *p, task_t *father, int traced) * group, and if no such member exists, give it to * the global child reaper process (ie "init") */ -static void forget_original_parent(struct task_struct * father, - struct list_head *to_release) +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; @@ -634,7 +684,7 @@ static void forget_original_parent(struct task_struct * father, */ list_for_each_safe(_p, _n, &father->children) { int ptrace; - p = list_entry(_p,struct task_struct,sibling); + p = list_entry(_p, struct task_struct, sibling); ptrace = p->ptrace; @@ -643,7 +693,7 @@ static void forget_original_parent(struct task_struct * father, if (father == p->real_parent) { /* reparent with a reaper, real father it's us */ - choose_new_parent(p, reaper, child_reaper); + choose_new_parent(p, reaper); reparent_thread(p, father, 0); } else { /* reparent ptraced task to its real parent */ @@ -663,8 +713,8 @@ static void forget_original_parent(struct task_struct * father, 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, child_reaper); + p = list_entry(_p, struct task_struct, ptrace_list); + choose_new_parent(p, reaper); reparent_thread(p, father, 1); } } @@ -783,7 +833,7 @@ static void exit_notify(struct task_struct *tsk) list_for_each_safe(_p, _n, &ptrace_dead) { list_del_init(_p); - t = list_entry(_p,struct task_struct,ptrace_list); + t = list_entry(_p, struct task_struct, ptrace_list); release_task(t); } @@ -795,7 +845,9 @@ static void exit_notify(struct task_struct *tsk) fastcall NORET_TYPE void do_exit(long code) { struct task_struct *tsk = current; + struct taskstats *tidstats; int group_dead; + unsigned int mycpu; profile_task_exit(tsk); @@ -805,10 +857,8 @@ 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)) + if (unlikely(tsk == child_reaper)) panic("Attempted to kill init!"); - if (tsk->io_context) - exit_io_context(); if (unlikely(current->ptrace & PT_TRACE_EXIT)) { current->ptrace_message = code; @@ -822,25 +872,21 @@ 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; - /* - * Make sure we don't try to process any timer firings - * while we are already exiting. - */ - tsk->it_virt_expires = cputime_zero; - tsk->it_prof_expires = cputime_zero; - tsk->it_sched_expires = 0; - if (unlikely(in_atomic())) printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", current->comm, current->pid, preempt_count()); + taskstats_exit_alloc(&tidstats, &mycpu); + acct_update_integrals(tsk); if (tsk->mm) { update_hiwater_rss(tsk->mm); @@ -850,10 +896,23 @@ 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_send(tsk, tidstats, group_dead, mycpu); + taskstats_exit_free(tidstats); + exit_mm(tsk); + if (group_dead) + acct_process(); exit_sem(tsk); __exit_files(tsk); __exit_fs(tsk); @@ -877,19 +936,33 @@ fastcall NORET_TYPE void do_exit(long code) 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: + */ + 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: */ - mutex_debug_check_no_locks_held(tsk); + debug_check_no_locks_held(tsk); + + if (tsk->io_context) + exit_io_context(); + + if (tsk->splice_pipe) + __free_pipe_info(tsk->splice_pipe); - /* 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); @@ -898,7 +971,7 @@ NORET_TYPE void complete_and_exit(struct completion *comp, long code) { if (comp) complete(comp); - + do_exit(code); } @@ -909,13 +982,6 @@ 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). @@ -930,7 +996,6 @@ 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. */ @@ -940,7 +1005,6 @@ do_group_exit(int exit_code) zap_other_threads(current); } spin_unlock_irq(&sighand->siglock); - read_unlock(&tasklist_lock); } do_exit(exit_code); @@ -957,7 +1021,7 @@ 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) @@ -989,7 +1053,7 @@ 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)) @@ -998,12 +1062,13 @@ 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); @@ -1028,7 +1093,7 @@ 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) { @@ -1190,8 +1255,8 @@ 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; @@ -1270,7 +1335,7 @@ 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); @@ -1305,7 +1370,7 @@ 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) { @@ -1391,7 +1456,7 @@ 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) @@ -1480,8 +1545,7 @@ check_continued: 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);