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Dyninst API Work:
The
Dyninst API is a platform independent API for dynamically
instrumenting an
executing binary. Dynamic instrumentation has
been used to do runtime performance
analysis of
applications, computational steering and dynamic program
analysis.
The
model for using the Dyninst API has been to write a tool (the
mutator) using the
API to attach to a running process and
insert instrumentation into that process. Only
the mutatee's
process image in memory is updated with the instrumentation
code;
therefore the mutations are lost when the mutatee
process terminates.
Starting
a mutator process, parsing the symbol table of the mutatee and
inserting
(possibly) large amounts of instrumentation code can
have a significant cost. My
work for this project
implements a technique that allows users to save a copy of
the
mutatee, with all the mutations in place, back to disk as a
runnable executable
file. The new executable can then be run
as a stand alone application, without
the need for a mutator
process to recreate and reinsert the mutations. If the
user
wants to run the same mutator/mutatee pair multiple
times with exactly the same
mutations, producing a mutated
executable will save this initial setup cost for the
subsequent
runs. Moreover, the mutated executable is more suitable for
batch
processing environments than the mutator/mutatee
model. The executable
saving mechanism is currently
implemented in the Dyninst API for Solaris, Linux
and AIX.
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