forceredfine

ForceRedefine is a JVMTI agent designed for testing how redefiniton affects running processes. It allows one to force classes to be redefined by writing to a fifo or give a process a list of classes to try redefining. Currently the redefinition is limited to adding (or removing) a single NOP at the beginning of every function in the class.

Usage

Build

m libforceredefine

The libraries will be built for 32-bit, 64-bit, host and target. Below examples assume you want to use the 64-bit version.

ART

adb shell setenforce 0

adb push $ANDROID_PRODUCT_OUT/system/lib64/libforceredefine.so /data/local/tmp/

echo java/util/ArrayList > /tmp/classlist echo java/util/Arrays >> /tmp/classlist adb push /tmp/classlist /data/local/tmp/

adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist

Since the agent has no static state it can be attached multiple times to the same process.

adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist2 adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist

One can also use fifos to send classes interactively to the process. (TODO: Have the agent continue reading from the fifo even after it gets an EOF.)