signal: Pass pid and pid type into send_sigqueue

Make the code more maintainable by performing more of the signal
related work in send_sigqueue.

A quick inspection of do_timer_create will show that this code path
does not lookup a thread group by a thread's pid.  Making it safe
to find the task pointed to by it_pid with "pid_task(it_pid, type)";

This supports the changes needed in fork to tell if a signal was sent
to a single process or a group of processes.

Having the pid to task transition in signal.c will also make it easier
to sort out races with de_thread and and the thread group leader
exiting when it comes time to address that.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 2bdf08a2bae9..2d2e739fbc57 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -332,8 +332,8 @@ void posixtimer_rearm(struct siginfo *info)
 
 int posix_timer_event(struct k_itimer *timr, int si_private)
 {
-	struct task_struct *task;
-	int shared, ret = -1;
+	enum pid_type type;
+	int ret = -1;
 	/*
 	 * FIXME: if ->sigq is queued we can race with
 	 * dequeue_signal()->posixtimer_rearm().
@@ -347,13 +347,8 @@ int posix_timer_event(struct k_itimer *timr, int si_private)
 	 */
 	timr->sigq->info.si_sys_private = si_private;
 
-	rcu_read_lock();
-	task = pid_task(timr->it_pid, PIDTYPE_PID);
-	if (task) {
-		shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
-		ret = send_sigqueue(timr->sigq, task, shared);
-	}
-	rcu_read_unlock();
+	type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID;
+	ret = send_sigqueue(timr->sigq, timr->it_pid, type);
 	/* If we failed to send the signal the timer stops. */
 	return ret > 0;
 }