1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index be3f2bb6fcf3..fad7ff17e468 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -157,6 +157,19 @@ extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
  */
 #define NOTIFY_STOP             (NOTIFY_OK|NOTIFY_STOP_MASK)
 
+/* Encapsulate (negative) errno value (in particular, NOTIFY_BAD <=> EPERM). */
+static inline int notifier_from_errno(int err)
+{
+        return NOTIFY_STOP_MASK | (NOTIFY_OK - err);
+}
+
+/* Restore (negative) errno value from notify return value. */
+static inline int notifier_to_errno(int ret)
+{
+        ret &= ~NOTIFY_STOP_MASK;
+        return ret > NOTIFY_OK ? NOTIFY_OK - ret : 0;
+}
+
 /*
  *      Declared notifiers so far. I can imagine quite a few more chains
  *      over time (eg laptop power reset chains, reboot chain (to clean