Challenges:

• uprobes only works with VMA's backed by files while the code cache of the (Hotspot) JVM uses an anonymous region
• uprobes apparently doesn't allow the code memory region to be writable
• dynamic unloading of JIT code requires some process to unregister the probe in time
• it would be nice to access variables in a probe but then you need to know the mapping between Java / Bytecode variables and native registers / stack, the JVM tracks this information for various purposes, but it's probably not exposed in JVMTI