1# forceredfine
2
3ForceRedefine is a JVMTI agent designed for testing how redefiniton affects running processes. It
4allows one to force classes to be redefined by writing to a fifo or give a process a list of
5classes to try redefining. Currently the redefinition is limited to adding (or removing) a single
6NOP at the beginning of every function in the class.
7
8# Usage
9### Build
10>    `make libforceredefine`
11
12The libraries will be built for 32-bit, 64-bit, host and target. Below examples
13assume you want to use the 64-bit version.
14
15#### ART
16>    `adb shell setenforce 0`
17>
18>    `adb push $ANDROID_PRODUCT_OUT/system/lib64/libforceredefine.so /data/local/tmp/`
19>
20>    `echo java/util/ArrayList > /tmp/classlist`
21>    `echo java/util/Arrays >> /tmp/classlist`
22>    `adb push /tmp/classlist /data/local/tmp/`
23>
24>    `adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist`
25
26Since the agent has no static state it can be attached multiple times to the same process.
27
28>    `adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist`
29>    `adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist2`
30>    `adb shell am attach-agent $(adb shell pidof some.deubggable.app) /data/local/tmp/libforceredefine.so=/data/local/tmp/classlist`
31
32One can also use fifos to send classes interactively to the process. (TODO: Have the agent
33continue reading from the fifo even after it gets an EOF.)