1 files changed, 90 insertions, 47 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 8037405..bc0ec67 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -29,8 +29,11 @@
 #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>
@@ -48,15 +51,80 @@ 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);
+}
 
-	REMOVE_LINKS(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);
+		__cleanup_signal(sig);
+	}
 }
 
 void release_task(struct task_struct * p)
@@ -65,21 +133,14 @@ 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);
-	/*
-	 * 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
@@ -114,21 +175,6 @@ repeat:
 		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
@@ -236,10 +282,10 @@ 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;
@@ -536,13 +582,13 @@ 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;
 }
 
@@ -567,9 +613,9 @@ 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.
@@ -643,7 +689,7 @@ 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 */
@@ -664,7 +710,7 @@ static 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);
 	}
 }
@@ -805,7 +851,7 @@ 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 (unlikely(current->ptrace & PT_TRACE_EXIT)) {
@@ -852,6 +898,12 @@ fastcall NORET_TYPE void do_exit(long code)
 		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);
@@ -912,13 +964,6 @@ 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).
@@ -933,7 +978,6 @@ 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.  */
@@ -943,7 +987,6 @@ do_group_exit(int exit_code)
 			zap_other_threads(current);
 		}
 		spin_unlock_irq(&sighand->siglock);
-		read_unlock(&tasklist_lock);
 	}
 
 	do_exit(exit_code);
@@ -1273,7 +1316,7 @@ 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);