avr32: use set_current_blocked() in handle_signal/sys_rt_sigreturn

It is wrong to change ->blocked directly, see e6fa16ab.  Change
handle_signal() and sys_rt_sigreturn() to use the right helper,
set_current_blocked().

Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com>
Reviewed-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/avr32/kernel/signal.c

@@ -87,10 +87,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 		goto badframe;
 
 	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&set);
 
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
@@ -226,6 +223,7 @@ static inline void
 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 	      sigset_t *oldset, struct pt_regs *regs, int syscall)
 {
+	sigset_t blocked;
 	int ret;
 
 	/*
@@ -246,13 +244,10 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 	/*
 	 * Block the signal if we were successful.
 	 */
-	spin_lock_irq(&current->sighand->siglock);
-	sigorsets(&current->blocked, &current->blocked,
-		  &ka->sa.sa_mask);
+	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
 	if (!(ka->sa.sa_flags & SA_NODEFER))
-		sigaddset(&current->blocked, sig);
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+		sigaddset(&blocked, sig);
+	set_current_blocked(&blocked);
 }
 
 /*