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android / platform / external / rust / crates / libfuzzer-sys / 3b365827d2893f2662aefe03a1e1c8a42bdd92f0
commit3b365827d2893f2662aefe03a1e1c8a42bdd92f0[log] [tgz]
authorJames Farrell <[email protected]>Thu May 09 20:27:31 2024 +0000
committerAutomerger Merge Worker <[email protected]>Thu May 09 20:27:31 2024 +0000
tree2e650cadd121db07a3e4005c074542b1f898c4a0
parent9b8e31b23281356965d73a5b39f86b2c212b623c [diff]
parentd7cb33803b35b5329ebbf5215e804d3a0804c68c [diff]
Update Android.bp by running cargo_embargo am: c877c6d0bb am: d7cb33803b

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libfuzzer-sys/+/3080534

Change-Id: Ia1e75c9209c04fef862a71495a0a36c2079ac3bc
Signed-off-by: Automerger Merge Worker <[email protected]>
tree: 2e650cadd121db07a3e4005c074542b1f898c4a0
  1. .github/
  2. ci/
  3. libfuzzer/
  4. src/
  5. NOTICE ⇨ LICENSE
  6. .cargo_vcs_info.json
  7. .gitignore
  8. Android.bp
  9. build.rs
  10. Cargo.toml
  11. Cargo.toml.orig
  12. cargo_embargo.json
  13. CHANGELOG.md
  14. LICENSE
  15. LICENSE-APACHE
  16. LICENSE-MIT
  17. METADATA
  18. MODULE_LICENSE_APACHE2
  19. MODULE_LICENSE_MIT
  20. OWNERS
  21. README.md
  22. rust-toolchain
  23. update-libfuzzer.sh
README.md

The libfuzzer-sys Crate

Barebones wrapper around LLVM's libFuzzer runtime library.

The CPP parts are extracted from compiler-rt git repository with git filter-branch.

libFuzzer relies on LLVM sanitizer support. The Rust compiler has built-in support for LLVM sanitizer support, for now, it's limited to Linux. As a result, libfuzzer-sys only works on Linux.

Usage

Use cargo fuzz!

The recommended way to use this crate with cargo fuzz!.

Manual Usage

This crate can also be used manually as following:

First create a new cargo project:

$ cargo new --bin fuzzed
$ cd fuzzed

Then add a dependency on the fuzzer-sys crate and your own crate:

[dependencies]
libfuzzer-sys = "0.4.0"
your_crate = { path = "../path/to/your/crate" }

Change the fuzzed/src/main.rs to fuzz your code:

#![no_main]

use libfuzzer_sys::fuzz_target;

fuzz_target!(|data: &[u8]| {
    // code to fuzz goes here
});

Build by running the following command:

$ cargo rustc -- \
    -C passes='sancov' \
    -C llvm-args='-sanitizer-coverage-level=3' \
    -C llvm-args='-sanitizer-coverage-inline-8bit-counters' \
    -Z sanitizer=address

And finally, run the fuzzer:

$ ./target/debug/fuzzed

Linking to a local libfuzzer

When using libfuzzer-sys, you can provide your own libfuzzer runtime in two ways.

If you are developing a fuzzer, you can set the CUSTOM_LIBFUZZER_PATH environment variable to the path of your local libfuzzer runtime, which will then be linked instead of building libfuzzer as part of the build stage of libfuzzer-sys. For an example, to link to a prebuilt LLVM 16 libfuzzer, you could use:

$ export CUSTOM_LIBFUZZER_PATH=/usr/lib64/clang/16/lib/libclang_rt.fuzzer-x86_64.a
$ cargo fuzz run ...

Alternatively, you may also disable the default link_libfuzzer feature:

In Cargo.toml:

[dependencies]
libfuzzer-sys = { path = "../../libfuzzer", default-features = false }

Then link to your own runtime in your build.rs.

Updating libfuzzer from upstream

./update-libfuzzer.sh <github.com/llvm-mirror/llvm-project SHA1>

License

All files in libfuzzer directory are licensed NCSA.

Everything else is dual-licensed Apache 2.0 and MIT.