[PATCH] move __exit_signal() to kernel/exit.c

__exit_signal() is private to release_task() now.  I think it is better to
make it static in kernel/exit.c and export flush_sigqueue() instead - this
function is much more simple and straightforward.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 77c35ef..3823ec8 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -29,6 +29,7 @@
 #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>
@@ -62,6 +63,68 @@ static void __unhash_process(struct task_struct *p)
 	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. */
+	}
+
+	tsk->signal = NULL;
+	cleanup_sighand(tsk);
+	spin_unlock(&sighand->siglock);
+	rcu_read_unlock();
+
+	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)
 {
 	int zap_leader;