Add MemTagSanitizer documentation.

Summary: A lot of this is work in progress...

Reviewers: kcc, pcc

Subscribers: cryptoad, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69289
diff --git a/llvm/docs/Reference.rst b/llvm/docs/Reference.rst
index 4c421a20..8aef4ee 100644
--- a/llvm/docs/Reference.rst
+++ b/llvm/docs/Reference.rst
@@ -36,6 +36,7 @@
    ORCv2

    PDB/index

    ScudoHardenedAllocator

+   MemTagSanitizer

    SegmentedStacks

    StackMaps

    SpeculativeLoadHardening

@@ -187,6 +188,10 @@
 :doc:`ScudoHardenedAllocator`

   A library that implements a security-hardened `malloc()`.

 

+:doc:`MemTagSanitizer`

+  Security hardening for production code aiming to mitigate memory

+  related vulnerabilities. Based on ARMv9 Memory Tagging Extension.

+

 :doc:`Dependence Graphs <DependenceGraphs/index>`

   A description of the design of the various dependence graphs such as

   the DDG (Data Dependence Graph).