[S390] Use block_sigmask()

Use the new helper function introduced in commit 5e6292c
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures.

In the past some architectures got this code wrong, so using this
helper function should stop that from happening again.

Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/compat_signal.c

@@ -581,7 +581,6 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 int handle_signal32(unsigned long sig, struct k_sigaction *ka,
 		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
 {
-	sigset_t blocked;
 	int ret;
 
 	/* Set up the stack frame */
@@ -591,10 +590,7 @@ int handle_signal32(unsigned long sig, struct k_sigaction *ka,
 		ret = setup_frame32(sig, ka, oldset, regs);
 	if (ret)
 		return ret;
-	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
-	if (!(ka->sa.sa_flags & SA_NODEFER))
-		sigaddset(&blocked, sig);
-	set_current_blocked(&blocked);
+	block_sigmask(ka, sig);
 	return 0;
 }
 

arch/s390/kernel/signal.c

@@ -384,7 +384,6 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
 			 siginfo_t *info, sigset_t *oldset,
 			 struct pt_regs *regs)
 {
-	sigset_t blocked;
 	int ret;
 
 	/* Set up the stack frame */
@@ -394,10 +393,7 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
 		ret = setup_frame(sig, ka, oldset, regs);
 	if (ret)
 		return ret;
-	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
-	if (!(ka->sa.sa_flags & SA_NODEFER))
-		sigaddset(&blocked, sig);
-	set_current_blocked(&blocked);
+	block_sigmask(ka, sig);
 	return 0;
 }