[ARM] 3448/1: [S3C2410] Settle delay when _enabling_ USB PLL
[safe/jmp/linux-2.6] / kernel / exit.c
index 2d39ccc..6c2eeb8 100644 (file)
@@ -10,6 +10,7 @@
 #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/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 <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -45,15 +51,85 @@ 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_init(&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;
 
-       REMOVE_LINKS(p);
+       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);
+               __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)
@@ -62,22 +138,14 @@ void release_task(struct task_struct * p)
        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);
-       __exit_sighand(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
@@ -105,28 +173,13 @@ repeat:
        spin_unlock(&p->proc_lock);
        proc_pid_flush(proc_dentry);
        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
@@ -191,7 +244,7 @@ int is_orphaned_pgrp(int pgrp)
        return retval;
 }
 
-static inline int has_stopped_jobs(int pgrp)
+static int has_stopped_jobs(int pgrp)
 {
        int retval = 0;
        struct task_struct *p;
@@ -228,21 +281,23 @@ static inline int has_stopped_jobs(int pgrp)
  *
  * NOTE that reparent_to_init() gives the caller full capabilities.
  */
-static inline void reparent_to_init(void)
+static void reparent_to_init(void)
 {
        write_lock_irq(&tasklist_lock);
 
        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) && (task_nice(current) < 0))
+       if ((current->policy == SCHED_NORMAL ||
+                       current->policy == SCHED_BATCH)
+                               && (task_nice(current) < 0))
                set_user_nice(current, 0);
        /* cpus_allowed? */
        /* rt_priority? */
@@ -257,7 +312,7 @@ static inline void reparent_to_init(void)
 
 void __set_special_pids(pid_t session, pid_t pgrp)
 {
-       struct task_struct *curr = current;
+       struct task_struct *curr = current->group_leader;
 
        if (curr->signal->session != session) {
                detach_pid(curr, PIDTYPE_SID);
@@ -341,9 +396,9 @@ 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);
@@ -356,6 +411,9 @@ 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_files(current);
        current->files = init_task.files;
        atomic_inc(&current->files->count);
@@ -365,7 +423,7 @@ void daemonize(const char *name, ...)
 
 EXPORT_SYMBOL(daemonize);
 
-static inline void close_files(struct files_struct * files)
+static void close_files(struct files_struct * files)
 {
        int i, j;
        struct fdtable *fdt;
@@ -529,17 +587,17 @@ 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(task_t *p, task_t *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 inline void reparent_thread(task_t *p, task_t *father, int traced)
+static void reparent_thread(task_t *p, task_t *father, int traced)
 {
        /* We don't want people slaying init.  */
        if (p->exit_signal != -1)
@@ -547,7 +605,7 @@ static inline void reparent_thread(task_t *p, task_t *father, int traced)
 
        if (p->pdeath_signal)
                /* We already hold the tasklist_lock here.  */
-               group_send_sig_info(p->pdeath_signal, (void *) 0, p);
+               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)) {
@@ -560,9 +618,9 @@ static inline 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.
@@ -591,8 +649,8 @@ static inline void reparent_thread(task_t *p, task_t *father, int traced)
                int pgrp = process_group(p);
 
                if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
-                       __kill_pg_info(SIGHUP, (void *)1, pgrp);
-                       __kill_pg_info(SIGCONT, (void *)1, pgrp);
+                       __kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+                       __kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp);
                }
        }
 }
@@ -603,7 +661,7 @@ static inline 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 inline void forget_original_parent(struct task_struct * father,
+static void forget_original_parent(struct task_struct * father,
                                          struct list_head *to_release)
 {
        struct task_struct *p, *reaper = father;
@@ -636,7 +694,7 @@ static inline 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 */
@@ -657,7 +715,7 @@ static inline void forget_original_parent(struct task_struct * father,
        }
        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);
+               choose_new_parent(p, reaper);
                reparent_thread(p, father, 1);
        }
 }
@@ -727,8 +785,8 @@ static void exit_notify(struct task_struct *tsk)
            (t->signal->session == tsk->signal->session) &&
            will_become_orphaned_pgrp(process_group(tsk), tsk) &&
            has_stopped_jobs(process_group(tsk))) {
-               __kill_pg_info(SIGHUP, (void *)1, process_group(tsk));
-               __kill_pg_info(SIGCONT, (void *)1, 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 
@@ -798,10 +856,8 @@ 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;
@@ -815,6 +871,8 @@ 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();
        }
@@ -841,10 +899,16 @@ fastcall NORET_TYPE void do_exit(long code)
        }
        group_dead = atomic_dec_and_test(&tsk->signal->live);
        if (group_dead) {
-               del_timer_sync(&tsk->signal->real_timer);
+               hrtimer_cancel(&tsk->signal->real_timer);
                exit_itimers(tsk->signal);
                acct_process(code);
        }
+       if (unlikely(tsk->robust_list))
+               exit_robust_list(tsk);
+#ifdef CONFIG_COMPAT
+       if (unlikely(tsk->compat_robust_list))
+               compat_exit_robust_list(tsk);
+#endif
        exit_mm(tsk);
 
        exit_sem(tsk);
@@ -858,16 +922,24 @@ fastcall NORET_TYPE void do_exit(long code)
        if (group_dead && tsk->signal->leader)
                disassociate_ctty(1);
 
-       module_put(tsk->thread_info->exec_domain->module);
+       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);
 #ifdef CONFIG_NUMA
        mpol_free(tsk->mempolicy);
        tsk->mempolicy = NULL;
 #endif
+       /*
+        * If DEBUG_MUTEXES is on, make sure we are holding no locks:
+        */
+       mutex_debug_check_no_locks_held(tsk);
+
+       if (tsk->io_context)
+               exit_io_context();
 
        /* PF_DEAD causes final put_task_struct after we schedule. */
        preempt_disable();
@@ -897,13 +969,6 @@ 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).
@@ -918,18 +983,15 @@ 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.  */
                        exit_code = sig->group_exit_code;
                else {
-                       sig->flags = SIGNAL_GROUP_EXIT;
                        sig->group_exit_code = exit_code;
                        zap_other_threads(current);
                }
                spin_unlock_irq(&sighand->siglock);
-               read_unlock(&tasklist_lock);
        }
 
        do_exit(exit_code);
@@ -1066,6 +1128,9 @@ static int wait_task_zombie(task_t *p, int noreap,
        }
 
        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
@@ -1082,24 +1147,26 @@ static int wait_task_zombie(task_t *p, int noreap,
                 * here reaping other children at the same time.
                 */
                spin_lock_irq(&p->parent->sighand->siglock);
-               p->parent->signal->cutime =
-                       cputime_add(p->parent->signal->cutime,
+               psig = p->parent->signal;
+               sig = p->signal;
+               psig->cutime =
+                       cputime_add(psig->cutime,
                        cputime_add(p->utime,
-                       cputime_add(p->signal->utime,
-                                   p->signal->cutime)));
-               p->parent->signal->cstime =
-                       cputime_add(p->parent->signal->cstime,
+                       cputime_add(sig->utime,
+                                   sig->cutime)));
+               psig->cstime =
+                       cputime_add(psig->cstime,
                        cputime_add(p->stime,
-                       cputime_add(p->signal->stime,
-                                   p->signal->cstime)));
-               p->parent->signal->cmin_flt +=
-                       p->min_flt + p->signal->min_flt + p->signal->cmin_flt;
-               p->parent->signal->cmaj_flt +=
-                       p->maj_flt + p->signal->maj_flt + p->signal->cmaj_flt;
-               p->parent->signal->cnvcsw +=
-                       p->nvcsw + p->signal->nvcsw + p->signal->cnvcsw;
-               p->parent->signal->cnivcsw +=
-                       p->nivcsw + p->signal->nivcsw + p->signal->cnivcsw;
+                       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);
        }
 
@@ -1254,7 +1321,7 @@ 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);