1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 9a32bc2088c9..811b5d440617 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2735,6 +2735,51 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
 }
 EXPORT_SYMBOL(sigprocmask);
 
+/*
+ * The api helps set app-provided sigmasks.
+ *
+ * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
+ * epoll_pwait where a new sigmask is passed from userland for the syscalls.
+ */
+int set_user_sigmask(const sigset_t __user *usigmask, sigset_t *set,
+		     sigset_t *oldset, size_t sigsetsize)
+{
+	if (!usigmask)
+		return 0;
+
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+	if (copy_from_user(set, usigmask, sizeof(sigset_t)))
+		return -EFAULT;
+
+	*oldset = current->blocked;
+	set_current_blocked(set);
+
+	return 0;
+}
+EXPORT_SYMBOL(set_user_sigmask);
+
+#ifdef CONFIG_COMPAT
+int set_compat_user_sigmask(const compat_sigset_t __user *usigmask,
+			    sigset_t *set, sigset_t *oldset,
+			    size_t sigsetsize)
+{
+	if (!usigmask)
+		return 0;
+
+	if (sigsetsize != sizeof(compat_sigset_t))
+		return -EINVAL;
+	if (get_compat_sigset(set, usigmask))
+		return -EFAULT;
+
+	*oldset = current->blocked;
+	set_current_blocked(set);
+
+	return 0;
+}
+EXPORT_SYMBOL(set_compat_user_sigmask);
+#endif
+
 /**
  *  sys_rt_sigprocmask - change the list of currently blocked signals
  *  @how: whether to add, remove, or set signals