pyvex

A python interface into Valgrind's VEX IR!

Build

For now, pyvex is tricky to build. First, valgrind needs to be compiled with fPIC:

mkdir ~/valgrind
cd ~/valgrind
wget http://valgrind.org/downloads/valgrind-3.8.1.tar.bz2
tar xvfj valgrind-3.8.1.tar.bz2
cd valgrind-3.8.1
CFLAGS=-fPIC ./configure --prefix=$HOME/valgrind/inst
make
make install

Great! Now you can build pyvex. First, you need to build the stuff in the angr/vex directory. Then, you can build pyvex!

python setup.py build

Sweet!

Use

You can use pyvex pretty easily. For now, it only supports translation and pretty printing:

import pyvex
irsb = pyvex.IRSB(bytes="\x55\xc3") # translates "push ebp; ret" to VEX IR
irsb.pp() # prints the VEX IR

Awesome stuff!

Bugs

• help() is sorely lacking
• pretty-printing an emptyIRSB segfaults
• there is no memory management. VEX is kind of weird with this, so care will have to be taken...
• converting from string to tag is currently very slow (a hastily written consecutive bunch of strcmps)
• IRCallee assumes that addresses are 64-bytes long, and will corrupt memory otherwise. This can be fixed by writing a getter/setter instead of using the macroed ones.
• CCalls are created by creating the IRCallee and manually building the args list, instead of by calling the helper functions. Not sure if this is good or bad. On the other hand, Dirty statements are created through helper functions.
• deepCopying a binder IRExpr seems to crash VEX
• IRDirty's fxState array access is untested
• equality (for those things that easily have it) should be implemented as a rich comparator