Dynamic analyses such as those implemented by compiler sanitizers
and Valgrind are effective at finding and diagnosing challenging
bugs and security vulnerabilities. However, most analyses cannot
be combined on the same program execution, and they incur a
high overhead, which typically prevents them from being used in
production.
This paper addresses the ambitious goal of running concurrently
multiple incompatible stock dynamic analysis tools in production,
without requiring any modifications to the tools themselves or
adding significant runtime overhead to the deployed system. This is
accomplished using multi-version execution, in which the dynamic
analyses are run concurrently with the native version, all on the
same program execution.
We implement our approach in a system called
FreeDA
and show
that it is applicable to several common scenarios, involving network
servers and interactive applications. In particular, we show how
incompatible stock dynamic analyses implemented by Clang’s sani-
tizers and Valgrind can be used to check high-performance servers
such as Memcached, Nginx and Redis, and interactive applications
such as Git, HTop and OpenSSH.