SIGSEGV compiling afl-coverage for examples/hello.rs

[tbg]

@bb80fc56f5ba096406c61f1790886d8edce878c9, $(which rustc) == /Users/tschottdorf/rust/rust/x86_64-apple-darwin/stage2/bin/rustc @ 1.0.0-beta-6833-g079f384:

$ cargo build --example hello --verbose
       Fresh gcc v0.3.19
       Fresh byteorder v0.3.13
   Compiling afl-coverage v0.0.1 (file:///Users/tschottdorf/rust/afl.rs)
     Running `/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/build-script-build`
       Fresh afl-coverage-plugin v0.0.1 (file:///Users/tschottdorf/rust/afl.rs)
     Running `rustc src/lib.rs --crate-name afl_coverage --crate-type lib -g --out-dir /Users/tschottdorf/rust/afl.rs/target/debug --emit=dep-info,link -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug/deps -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out -l static=afl-llvm-rt`
     Running `rustc examples/hello.rs --crate-name hello --crate-type bin -g --out-dir /Users/tschottdorf/rust/afl.rs/target/debug/examples --emit=dep-info,link -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug/deps --extern byteorder=/Users/tschottdorf/rust/afl.rs/target/debug/deps/libbyteorder-3e27c88aa235985f.rlib --extern afl_coverage_plugin=/Users/tschottdorf/rust/afl.rs/target/debug/deps/libafl_coverage_plugin-a9b7f43301ffb1fc.dylib --extern afl_coverage=/Users/tschottdorf/rust/afl.rs/target/debug/libafl_coverage.rlib -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out`
afl-llvm-pass 1.77b by <lszekeres@google.com>
Could not compile `afl-coverage`.

Caused by:
  Process didn't exit successfully: `rustc examples/hello.rs --crate-name hello --crate-type bin -g --out-dir /Users/tschottdorf/rust/afl.rs/target/debug/examples --emit=dep-info,link -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug -L dependency=/Users/tschottdorf/rust/afl.rs/target/debug/deps --extern byteorder=/Users/tschottdorf/rust/afl.rs/target/debug/deps/libbyteorder-3e27c88aa235985f.rlib --extern afl_coverage_plugin=/Users/tschottdorf/rust/afl.rs/target/debug/deps/libafl_coverage_plugin-a9b7f43301ffb1fc.dylib --extern afl_coverage=/Users/tschottdorf/rust/afl.rs/target/debug/libafl_coverage.rlib -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out -L native=/Users/tschottdorf/rust/afl.rs/target/debug/build/afl-coverage-f64ebee15259fa44/out` (signal: 11)

I've tried lldb to get more info about the segfault as in #11 but I can't just re-run the failing command (it needs the right env, I think) and wasn't versed enough to get lldb to attach to the forked child in cargo build. Pointers appreciated.

[tbg]

ok, complete lie about lldb. Here's something:

Process 70430 launched: '/Users/tschottdorf/rust/rust/x86_64-apple-darwin/stage2/bin/rustc' (x86_64)
afl-llvm-pass 1.77b by <lszekeres@google.com>
Process 70430 stopped
* thread #2: tid = 0x4c764, 0x0000000102f14efe librustc_llvm-bb943c5a.dylib`llvm::PointerType::get(llvm::Type*, unsigned int) + 30, name = 'rustc', stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT)
    frame #0: 0x0000000102f14efe librustc_llvm-bb943c5a.dylib`llvm::PointerType::get(llvm::Type*, unsigned int) + 30
librustc_llvm-bb943c5a.dylib`llvm::PointerType::get:
->  0x102f14efe <+30>: movq   (%rax), %r14
    0x102f14f01 <+33>: testl  %r13d, %r13d
    0x102f14f04 <+36>: je     0x102f14f5a               ; <+122>
    0x102f14f06 <+38>: leaq   0x770(%r14), %rbx

[frewsxcv]

A couple suggestions:

1. Could you try using this revision with rustc? It's the revision I use and it seems to work alright for the time being
2. Alternatively, use my Vagrantfile (with Vagrant) in this PR. It should set up all the dependencies to be in a working state.

I'm working on the documentation and a small tutorial to make this process easier since I know it is not at easy at the moment (mostly thanks to the issue in #11 which I will need to look into eventually). Please report back!

[frewsxcv]

There's no reason to have the Vagrantfile sitting in a PR, so I merged it in. You can find it in the etc folder

https://github.com/frewsxcv/afl.rs/blob/master/etc/Vagrantfile

[tbg]

Thanks @frewsxcv, running it at rust-lang/rust@717e8831b did the trick.
If this is a duplicate of #11, feel free to close this.

[frewsxcv]

Glad to hear it worked out! Hopefully I'll get some better documentation done soon...