signal: cleanup sys_sigprocmask()

Cleanup. Remove the unneeded goto's, we can simply read blocked.sig[0]
unconditionally and then copy-to-user it if oset != NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>

kernel/signal.c

@@ -2889,29 +2889,28 @@ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
 /**
  *  sys_sigprocmask - examine and change blocked signals
  *  @how: whether to add, remove, or set signals
- *  @set: signals to add or remove (if non-null)
+ *  @nset: signals to add or remove (if non-null)
  *  @oset: previous value of signal mask if non-null
  *
  * Some platforms have their own version with special arguments;
  * others support only sys_rt_sigprocmask.
  */
 
-SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set,
+SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset,
 		old_sigset_t __user *, oset)
 {
-	int error;
 	old_sigset_t old_set, new_set;
+	int error;
 
-	if (set) {
-		error = -EFAULT;
-		if (copy_from_user(&new_set, set, sizeof(*set)))
-			goto out;
-		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
+	old_set = current->blocked.sig[0];
 
-		spin_lock_irq(&current->sighand->siglock);
-		old_set = current->blocked.sig[0];
+	if (nset) {
+		if (copy_from_user(&new_set, nset, sizeof(*nset)))
+			return -EFAULT;
+		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
 
 		error = 0;
+		spin_lock_irq(&current->sighand->siglock);
 		switch (how) {
 		default:
 			error = -EINVAL;
@@ -2930,19 +2929,15 @@ SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set,
 		recalc_sigpending();
 		spin_unlock_irq(&current->sighand->siglock);
 		if (error)
-			goto out;
-		if (oset)
-			goto set_old;
-	} else if (oset) {
-		old_set = current->blocked.sig[0];
-	set_old:
-		error = -EFAULT;
+			return error;
+	}
+
+	if (oset) {
 		if (copy_to_user(oset, &old_set, sizeof(*oset)))
-			goto out;
+			return -EFAULT;
 	}
-	error = 0;
-out:
-	return error;
+
+	return 0;
 }
 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */