Index: cfe/trunk/docs/ReleaseNotes.rst
===================================================================
--- cfe/trunk/docs/ReleaseNotes.rst
+++ cfe/trunk/docs/ReleaseNotes.rst
@@ -229,7 +229,10 @@
 Undefined Behavior Sanitizer (UBSan)
 ------------------------------------
 
-...
+* A minimal runtime is now available. It is suitable for use in production
+  environments, and has a small attack surface. It only provides very basic
+  issue logging and deduplication, and does not support ``-fsanitize=vptr``
+  checking.
 
 Core Analysis Improvements
 ==========================
Index: cfe/trunk/docs/UndefinedBehaviorSanitizer.rst
===================================================================
--- cfe/trunk/docs/UndefinedBehaviorSanitizer.rst
+++ cfe/trunk/docs/UndefinedBehaviorSanitizer.rst
@@ -155,6 +155,19 @@
 The ``null``, ``alignment``, ``object-size``, and ``vptr`` checks do not apply
 to pointers to types with the ``volatile`` qualifier.
 
+Minimal Runtime
+===============
+
+There is a minimal UBSan runtime available suitable for use in production
+environments. This runtime has a small attack surface. It only provides very
+basic issue logging and deduplication, and does not support ``-fsanitize=vptr``
+checking.
+
+To use the minimal runtime, add ``-fsanitize-minimal-runtime`` to the clang
+command line options. For example, if you're used to compiling with
+``-fsanitize=undefined``, you could enable the minimal runtime with
+``-fsanitize=undefined -fsanitize-minimal-runtime``.
+
 Stack traces and report symbolization
 =====================================
 If you want UBSan to print symbolized stack trace for each error report, you