[patch V5 02/26] signal: Cleanup flush_sigqueue_mask()

[Thomas Gleixner]

Mop up the stale return value comment and add a lockdep check instead of
commenting on the locking requirement.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 kernel/signal.c |   27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -704,17 +704,14 @@ void signal_wake_up_state(struct task_st
 		kick_process(t);
 }
 
-/*
- * Remove signals in mask from the pending set and queue.
- * Returns 1 if any signals were found.
- *
- * All callers must be holding the siglock.
- */
-static void flush_sigqueue_mask(sigset_t *mask, struct sigpending *s)
+/* Remove signals in mask from the pending set and queue. */
+static void flush_sigqueue_mask(struct task_struct *p, sigset_t *mask, struct sigpending *s)
 {
 	struct sigqueue *q, *n;
 	sigset_t m;
 
+	lockdep_assert_held(&p->sighand->siglock);
+
 	sigandsets(&m, mask, &s->signal);
 	if (sigisemptyset(&m))
 		return;
@@ -848,18 +845,18 @@ static bool prepare_signal(int sig, stru
 		 * This is a stop signal.  Remove SIGCONT from all queues.
 		 */
 		siginitset(&flush, sigmask(SIGCONT));
-		flush_sigqueue_mask(&flush, &signal->shared_pending);
+		flush_sigqueue_mask(p, &flush, &signal->shared_pending);
 		for_each_thread(p, t)
-			flush_sigqueue_mask(&flush, &t->pending);
+			flush_sigqueue_mask(p, &flush, &t->pending);
 	} else if (sig == SIGCONT) {
 		unsigned int why;
 		/*
 		 * Remove all stop signals from all queues, wake all threads.
 		 */
 		siginitset(&flush, SIG_KERNEL_STOP_MASK);
-		flush_sigqueue_mask(&flush, &signal->shared_pending);
+		flush_sigqueue_mask(p, &flush, &signal->shared_pending);
 		for_each_thread(p, t) {
-			flush_sigqueue_mask(&flush, &t->pending);
+			flush_sigqueue_mask(p, &flush, &t->pending);
 			task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
 			if (likely(!(t->ptrace & PT_SEIZED))) {
 				t->jobctl &= ~JOBCTL_STOPPED;
@@ -4114,8 +4111,8 @@ void kernel_sigaction(int sig, __sighand
 		sigemptyset(&mask);
 		sigaddset(&mask, sig);
 
-		flush_sigqueue_mask(&mask, &current->signal->shared_pending);
-		flush_sigqueue_mask(&mask, &current->pending);
+		flush_sigqueue_mask(current, &mask, &current->signal->shared_pending);
+		flush_sigqueue_mask(current, &mask, &current->pending);
 		recalc_sigpending();
 	}
 	spin_unlock_irq(&current->sighand->siglock);
@@ -4182,9 +4179,9 @@ int do_sigaction(int sig, struct k_sigac
 		if (sig_handler_ignored(sig_handler(p, sig), sig)) {
 			sigemptyset(&mask);
 			sigaddset(&mask, sig);
-			flush_sigqueue_mask(&mask, &p->signal->shared_pending);
+			flush_sigqueue_mask(p, &mask, &p->signal->shared_pending);
 			for_each_thread(p, t)
-				flush_sigqueue_mask(&mask, &t->pending);
+				flush_sigqueue_mask(p, &mask, &t->pending);
 		}
 	}