[PATCH] signal: cleanup the .si_signo checks in dequeue_synchronous_signal()

[Oleg Nesterov]

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
 kernel/signal.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 7386b9552dc3..9cfd4d03cad4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -676,21 +676,24 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info)
 	struct task_struct *tsk = current;
 	struct sigpending *pending = &tsk->pending;
 	struct sigqueue *q, *sync = NULL;
+	unsigned long mask;
+	sigset_t xxx;
 
 	/*
 	 * Might a synchronous signal be in the queue?
 	 */
-	if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK))
+	mask = (pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK;
+	if (!mask)
 		return 0;
 
+	siginitset(&xxx, mask);
 	/*
 	 * Return the first synchronous signal in the queue.
 	 */
 	list_for_each_entry(q, &pending->list, list) {
 		/* Synchronous signals have a positive si_code */
-		if ((q->info.si_code > SI_USER) &&
-		    (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK) &&
-		    !sigismember(&tsk->blocked, q->info.si_signo)) {
+		if (SI_FROMKERNEL(&q->info) &&
+		    sigismember(&xxx, q->info.si_signo)) {
 			sync = q;
 			goto next;
 		}
-- 
2.55.0