Make unicornafl more Rust-friendly and sync with newest unicorn-engine Rust crate

[Evian-Zhang]

In this PR, there are two closely-related changes (it should be noted that the functionality and logic are never changed and everything would just work fine, no breaking changes.):

• Current code is synced with newest unicorn-engine Rust crate.

  Since the unicorn-engine binding and wrapper have been greatly refactored and improved.

• Some APIs and internal structures are refactored to be more Rust-friendly.

  The ultimate entrypoint is refactored into four functions in lib.rs: afl_fuzz_custom, afl_fuzz, uc_afl_fuzz, uc_afl_fuzz_custom. The first two are for Rust-users, and the last two are for FFI users (The real implementation is still the child_fuzz in target.rs, those four are just some wrappers).

  Since we can only expose fuzzing entrypoint to FFI users, the internal design, as a result, can be pure Rust, and no extern "C", no c_void, no *mut. This could not only improve the maintenance of this library, but also potentially improve the performance for both Rust users and FFI users.

[wtdcode]

Could you try cargo miri on the sample?

*I should also add a CI for that.

[Evian-Zhang]

Sure, I'll test it tomorrow.

[wtdcode]

Also we now further depend on unicorn@dev. We should reflect that in the Cargo.toml

[Evian-Zhang]

Could you trycargo miri on the sample?

I tried cargo +nightly miri run --example sample, but it does not support FFI function calls (BTW, the compilation for libafl_targets took forever):

error: unsupported operation: can't call foreign function `uc_open` on OS `linux`
   --> /home/aota/.cargo/git/checkouts/unicorn-a201e6327e516c06/89a1422/bindings/rust/src/lib.rs:191:18
    |
191 |         unsafe { uc_open(arch, mode, &mut handle) }.and_then(|| {
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't call foreign function `uc_open` on OS `linux`
    |
    = help: if this is a basic API commonly used on this target, please report an issue with Miri
    = help: however, note that Miri does not aim to support every FFI function out there; for instance, we will not support APIs for things such as GUIs, scripting languages, or databases
    = note: BACKTRACE:
    = note: inside `unicorn_engine::Unicorn::<'_, unicornafl::executor::UnicornFuzzData<()>>::new_with_data` at /home/aota/.cargo/git/checkouts/unicorn-a201e6327e516c06/89a1422/bindings/rust/src/lib.rs:191:18: 191:50
note: inside `main`
   --> examples/sample.rs:27:18
    |
27  |     let mut uc = Unicorn::new_with_data(Arch::X86, Mode::MODE_64, UnicornFuzzData::default())
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

And you should also patch your libafl to add not(miri) here. (BTW, would you mind telling why maintaining a separate fork instead of pushing to LibAFL mainstream repo?)

Also we now further depend on unicorn@dev. We should reflect that in the Cargo.toml

Currently in Cargo.toml, it has already in there:

unicorn-engine = { git = "https://github.com/unicorn-engine/unicorn", branch = "dev"}

[wtdcode]

Could you trycargo miri on the sample?

I tried cargo +nightly miri run --example sample, but it does not support FFI function calls (BTW, the compilation for libafl_targets took forever):

error: unsupported operation: can't call foreign function `uc_open` on OS `linux`
   --> /home/aota/.cargo/git/checkouts/unicorn-a201e6327e516c06/89a1422/bindings/rust/src/lib.rs:191:18
    |
191 |         unsafe { uc_open(arch, mode, &mut handle) }.and_then(|| {
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't call foreign function `uc_open` on OS `linux`
    |
    = help: if this is a basic API commonly used on this target, please report an issue with Miri
    = help: however, note that Miri does not aim to support every FFI function out there; for instance, we will not support APIs for things such as GUIs, scripting languages, or databases
    = note: BACKTRACE:
    = note: inside `unicorn_engine::Unicorn::<'_, unicornafl::executor::UnicornFuzzData<()>>::new_with_data` at /home/aota/.cargo/git/checkouts/unicorn-a201e6327e516c06/89a1422/bindings/rust/src/lib.rs:191:18: 191:50
note: inside `main`
   --> examples/sample.rs:27:18
    |
27  |     let mut uc = Unicorn::new_with_data(Arch::X86, Mode::MODE_64, UnicornFuzzData::default())
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I use MIRIFLAGS="-Zmiri-disable-isolation" locally.

And you should also patch your libafl to add not(miri) here. (BTW, would you mind telling why maintaining a separate fork instead of pushing to LibAFL mainstream repo?)

It is just not ready and the code need some cleanup

AFLplusplus/LibAFL#3087

Also we now further depend on unicorn@dev. We should reflect that in the Cargo.toml

Currently in Cargo.toml, it has already in there:

unicorn-engine = { git = "https://github.com/unicorn-engine/unicorn", branch = "dev"}

Okay I see.

[Evian-Zhang]

Setting MIRIFLAGS="-Zmiri-disable-isolation" still turns out the same error in my local machine (latest rustc nightly in Ubuntu).

[wtdcode]

I see, miri always fails =(.