v8/test/fuzzer
Jakob Gruber a8c62102e1 [regexp] Further narrow public API and restrict includes to regexp.h
This CL renames jsregexp.{h,cc} to regexp.{h,cc}, hides all non-public
functions of RegExpImpl in the .cc file, and renames the public parts
of RegExpImpl to just RegExp. Include directives from outside the
src/regexp directory are limited to regexp.h, regexp-stack.h, and
regexp-utils.h. We also expose all result codes that can be returned
by irregexp code (including RETRY) on the public header since they
are needed elsewhere, e.g. in builtins.

Bug: v8:9359
Change-Id: Iae1a01ac9f6e1e4dc168f3fbe8fe8679cb6b1259
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1662297
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62240}
2019-06-18 12:23:16 +00:00
..
json Add json fuzzer 2016-02-02 11:29:01 +00:00
multi_return [turbofan] Add fuzzer to test different signatures for multi-returns 2018-01-12 12:20:27 +00:00
parser Add a library suitable for libfuzzer with a small unit test runner shell 2016-01-26 10:39:03 +00:00
regexp [regexp] add fuzzer support for regexp parser and compiler. 2016-02-01 14:00:38 +00:00
regexp_builtins [regexp] Initial go at a builtins fuzzer 2018-01-18 11:02:57 +00:00
wasm [wasm] Cleanup the wasm fuzzer corpus files. 2017-05-19 09:21:16 +00:00
wasm_async [wasm] Avoid executing infinite loops in the wasm fuzzers 2017-09-07 12:35:45 +00:00
wasm_code [wasm] Create a new fuzzer for wasm code. 2016-08-29 13:56:00 +00:00
wasm_compile [wasm] Syntax- and Type-aware Fuzzer 2017-02-17 17:06:29 +00:00
BUILD.gn [fuzzer] Remove the wasm section fuzzers 2019-01-11 15:18:47 +00:00
DEPS Add a library suitable for libfuzzer with a small unit test runner shell 2016-01-26 10:39:03 +00:00
fuzzer-support.cc Move remaining files in src/ 2019-05-24 18:24:36 +00:00
fuzzer-support.h [fuzzer] Use std::unique_ptr for the FuzzerSupport 2017-11-29 16:36:23 +00:00
fuzzer.cc [test/fuzzer] Fix cpplint complaints 2017-09-04 10:45:21 +00:00
fuzzer.status [test] Don't test jitless without embedded-builtins 2019-02-26 14:33:01 +00:00
json.cc [fuzzer] Fix OOM in v8_json_parser_fuzzer due to unnecessary long input. 2018-07-17 14:25:27 +00:00
multi-return.cc Move more relevant files to src/objects 2019-05-23 08:52:30 +00:00
OWNERS Add OWNERS files for src and test 2019-05-30 04:51:21 +00:00
parser.cc Move more relevant files to src/objects 2019-05-23 08:52:30 +00:00
README.md [gyp] move build targets for tests to gypfiles. 2018-01-30 06:31:00 +00:00
regexp-builtins.cc [regexp] Further narrow public API and restrict includes to regexp.h 2019-06-18 12:23:16 +00:00
regexp.cc [regexp] Further narrow public API and restrict includes to regexp.h 2019-06-18 12:23:16 +00:00
testcfg.py Reland "Reland "[test] refactor testsuite configuration"" 2019-02-06 09:02:09 +00:00
wasm_corpus.tar.gz.sha1 [wasm] Move the wasm fuzzer corpus to a different directory 2017-04-28 23:29:41 +00:00
wasm-async.cc Move more relevant files to src/objects 2019-05-23 08:52:30 +00:00
wasm-code.cc Move more relevant files to src/objects 2019-05-23 08:52:30 +00:00
wasm-compile.cc [wasm][fuzzer] Enable anyref for the wasm-compile fuzzer 2019-05-29 14:03:19 +00:00
wasm-fuzzer-common.cc Move utility code to src/utils 2019-05-23 14:13:34 +00:00
wasm-fuzzer-common.h [fuzzer] Remove the wasm section fuzzers 2019-01-11 15:18:47 +00:00
wasm.cc Move more relevant files to src/objects 2019-05-23 08:52:30 +00:00

How to make a libFuzzer fuzzer in V8

This document describes how to make a new libFuzzer fuzzer for V8. A general introduction to libFuzzer can be found here. In short, libFuzzer is an in-process coverage-driven evolutionary fuzzer. libFuzzer serves you with a sequence of byte arrays that you can use to test your code. libFuzzer tries to generate this sequence of byte arrays in a way that maximizes test coverage.

Warning: By itself libFuzzer typically does not generate valid JavaScript code.

Changes to V8

tldr: Do the same as https://codereview.chromium.org/2280623002 to introduce a new fuzzer to V8.

This is a step by step guide on how to make a new fuzzer in V8. In the example the fuzzer is called foo.

  1. Copy one of the existing fuzzer implementations in test/fuzzer/, e.g. cp wasm.cc foo.cc

    • Copying an existing fuzzer is a good idea to get all the required setup, e.g. setting up the isolate
  2. Create a directory called foo in test/fuzzer/ which contains at least one file

    • The file is used by the trybots to check whether the fuzzer actually compiles and runs
  3. Copy the build rules of an existing fuzzer in BUILD.gn, e.g. the build rules for the wasm.cc fuzzer are v8_source_set("wasm_fuzzer") and v8_fuzzer("wasm_fuzzer"). Note that the name has to be the name of the directory created in Step 2 + _fuzzer so that the scripts on the trybots work

  4. Now you can already compile the fuzzer, e.g. with ninja -j 1000 -C out/x64.debug/v8_simple_foo_fuzzer

    • Use this binary to reproduce issues found by cluster fuzz, e.g. out/x64.debug/v8_simple_foo_fuzzer testcase.foo
  5. Copy the binary name and the test directory name in test/fuzzer/fuzzer.isolate

  6. Add the fuzzer to the FuzzerTestSuite in test/fuzzer/testcfg.py

    • This step is needed to run the fuzzer with the files created in Step 2 on the trybots
  7. Commit the changes described above to the V8 repository

Changes to Chromium

tldr: Do the same as https://codereview.chromium.org/2344823002 to add the new fuzzer to cluster fuzz.

  1. Copy the build rules of an existing fuzzer in testing/libfuzzer/fuzzers/BUILD.gn, e.g. the build rule for the wasm.cc fuzzer is v8_wasm_fuzzer. There is no need to set a dictionary , or a seed_corpus. See chromium-fuzzing-getting-started for more information.

  2. Compile the fuzzer in chromium (for different configurations see: https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reference.md):

    • gn gen out/libfuzzer '--args=use_libfuzzer=true is_asan=true is_debug=false enable_nacl=false'

    • ninja -j 1000 -C out/libfuzzer/ v8_foo_fuzzer

  3. Run the fuzzer locally

    • mkdir /tmp/empty_corpus && out/libfuzzer/v8_foo_fuzzer /tmp/empty_corpus