]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/exit.c
[POWERPC] Consolidate cuboot initialization code
[linux-2.6-omap-h63xx.git] / kernel / exit.c
index 92369240d91d3a9582b490da701be24a6f81795f..5c8ecbaa19a530cc4d417a897457b0d0318bc39b 100644 (file)
@@ -7,7 +7,6 @@
 #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/pid_namespace.h>
 #include <linux/ptrace.h>
 #include <linux/profile.h>
+#include <linux/signalfd.h>
 #include <linux/mount.h>
 #include <linux/proc_fs.h>
+#include <linux/kthread.h>
 #include <linux/mempolicy.h>
 #include <linux/taskstats_kern.h>
 #include <linux/delayacct.h>
@@ -42,6 +43,7 @@
 #include <linux/audit.h> /* for audit_free() */
 #include <linux/resource.h>
 #include <linux/blkdev.h>
+#include <linux/task_io_accounting_ops.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -82,6 +84,14 @@ static void __exit_signal(struct task_struct *tsk)
        sighand = rcu_dereference(tsk->sighand);
        spin_lock(&sighand->siglock);
 
+       /*
+        * Notify that this sighand has been detached. This must
+        * be called with the tsk->sighand lock held. Also, this
+        * access tsk->sighand internally, so it must be called
+        * before tsk->sighand is reset.
+        */
+       signalfd_detach_locked(tsk);
+
        posix_cpu_timers_exit(tsk);
        if (atomic_dec_and_test(&sig->count))
                posix_cpu_timers_exit_group(tsk);
@@ -113,6 +123,8 @@ static void __exit_signal(struct task_struct *tsk)
                sig->nvcsw += tsk->nvcsw;
                sig->nivcsw += tsk->nivcsw;
                sig->sched_time += tsk->sched_time;
+               sig->inblock += task_io_get_inblock(tsk);
+               sig->oublock += task_io_get_oublock(tsk);
                sig = NULL; /* Marker for below. */
        }
 
@@ -255,26 +267,25 @@ static int has_stopped_jobs(struct pid *pgrp)
 }
 
 /**
- * reparent_to_init - Reparent the calling kernel thread to the init task of the pid space that the thread belongs to.
+ * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
  *
  * 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.
+ * it ever exits, it should generally reparent itself to kthreadd so it
+ * isn't in the way of other processes and 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.
+ * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
  */
-static void reparent_to_init(void)
+static void reparent_to_kthreadd(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);
+       current->real_parent = current->parent = kthreadd_task;
        add_parent(current);
 
        /* Set the exit signal to SIGCHLD so we signal init on exit */
@@ -300,12 +311,12 @@ void __set_special_pids(pid_t session, pid_t pgrp)
        if (process_session(curr) != session) {
                detach_pid(curr, PIDTYPE_SID);
                set_signal_session(curr->signal, session);
-               attach_pid(curr, PIDTYPE_SID, session);
+               attach_pid(curr, PIDTYPE_SID, find_pid(session));
        }
        if (process_group(curr) != pgrp) {
                detach_pid(curr, PIDTYPE_PGID);
                curr->signal->pgrp = pgrp;
-               attach_pid(curr, PIDTYPE_PGID, pgrp);
+               attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
        }
 }
 
@@ -348,7 +359,7 @@ int disallow_signal(int sig)
                return -EINVAL;
 
        spin_lock_irq(&current->sighand->siglock);
-       sigaddset(&current->blocked, sig);
+       current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
        return 0;
@@ -401,7 +412,7 @@ void daemonize(const char *name, ...)
        current->files = init_task.files;
        atomic_inc(&current->files->count);
 
-       reparent_to_init();
+       reparent_to_kthreadd();
 }
 
 EXPORT_SYMBOL(daemonize);
@@ -751,11 +762,8 @@ static void exit_notify(struct task_struct *tsk)
                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);
-                       }
+                       if (!signal_pending(t) && !(t->flags & PF_EXITING))
+                               recalc_sigpending_and_wake(t);
                spin_unlock_irq(&tsk->sighand->siglock);
                read_unlock(&tasklist_lock);
        }
@@ -884,13 +892,29 @@ 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");
+               /*
+                * We can do this unlocked here. The futex code uses
+                * this flag just to verify whether the pi state
+                * cleanup has been done or not. In the worst case it
+                * loops once more. We pretend that the cleanup was
+                * done as there is no way to return. Either the
+                * OWNER_DIED bit is set by now or we push the blocked
+                * task into the wait for ever nirwana as well.
+                */
+               tsk->flags |= PF_EXITPIDONE;
                if (tsk->io_context)
                        exit_io_context();
                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule();
        }
 
+       /*
+        * tsk->flags are checked in the futex code to protect against
+        * an exiting task cleaning up the robust pi futexes.
+        */
+       spin_lock_irq(&tsk->pi_lock);
        tsk->flags |= PF_EXITING;
+       spin_unlock_irq(&tsk->pi_lock);
 
        if (unlikely(in_atomic()))
                printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
@@ -904,7 +928,7 @@ fastcall NORET_TYPE void do_exit(long code)
        }
        group_dead = atomic_dec_and_test(&tsk->signal->live);
        if (group_dead) {
-               hrtimer_cancel(&tsk->signal->real_timer);
+               hrtimer_cancel(&tsk->signal->real_timer);
                exit_itimers(tsk->signal);
        }
        acct_collect(code, group_dead);
@@ -957,6 +981,12 @@ fastcall NORET_TYPE void do_exit(long code)
         * Make sure we are holding no locks:
         */
        debug_check_no_locks_held(tsk);
+       /*
+        * We can do this unlocked here. The futex code uses this flag
+        * just to verify whether the pi state cleanup has been done
+        * or not. In the worst case it loops once more.
+        */
+       tsk->flags |= PF_EXITPIDONE;
 
        if (tsk->io_context)
                exit_io_context();
@@ -1194,6 +1224,12 @@ static int wait_task_zombie(struct task_struct *p, int noreap,
                        p->nvcsw + sig->nvcsw + sig->cnvcsw;
                psig->cnivcsw +=
                        p->nivcsw + sig->nivcsw + sig->cnivcsw;
+               psig->cinblock +=
+                       task_io_get_inblock(p) +
+                       sig->inblock + sig->cinblock;
+               psig->coublock +=
+                       task_io_get_oublock(p) +
+                       sig->oublock + sig->coublock;
                spin_unlock_irq(&p->parent->sighand->siglock);
        }