+#ifdef TIF_RESTORE_SIGMASK
+/*
+ * Legacy restore_sigmask accessors. These are inefficient on
+ * SMP architectures because they require atomic operations.
+ */
+
+/**
+ * set_restore_sigmask() - make sure saved_sigmask processing gets done
+ *
+ * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
+ * will run before returning to user mode, to process the flag. For
+ * all callers, TIF_SIGPENDING is already set or it's no harm to set
+ * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
+ * arch code will notice on return to user mode, in case those bits
+ * are scarce. We set TIF_SIGPENDING here to ensure that the arch
+ * signal code always gets run when TIF_RESTORE_SIGMASK is set.
+ */
+static inline void set_restore_sigmask(void)
+{
+ set_thread_flag(TIF_RESTORE_SIGMASK);
+ WARN_ON(!test_thread_flag(TIF_SIGPENDING));
+}
+static inline void clear_restore_sigmask(void)
+{
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_restore_sigmask(void)
+{
+ return test_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+ return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+
+#else /* TIF_RESTORE_SIGMASK */
+
+/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
+static inline void set_restore_sigmask(void)
+{
+ current->restore_sigmask = true;
+ WARN_ON(!test_thread_flag(TIF_SIGPENDING));
+}
+static inline void clear_restore_sigmask(void)
+{
+ current->restore_sigmask = false;
+}
+static inline bool test_restore_sigmask(void)
+{
+ return current->restore_sigmask;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+ if (!current->restore_sigmask)
+ return false;
+ current->restore_sigmask = false;
+ return true;
+}
+#endif
+