[libFuzzer] document -fork=N

llvm-svn: 354533
This commit is contained in:
Kostya Serebryany 2019-02-21 00:32:30 +00:00
parent 71f2a5e60f
commit 9c9a8a96d3
1 changed files with 22 additions and 0 deletions

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@ -178,6 +178,28 @@ worker processes can be overridden by the ``-workers=N`` option. For example,
running with ``-jobs=30`` on a 12-core machine would run 6 workers by default,
with each worker averaging 5 bugs by completion of the entire process.
Fork mode
---------
**Experimental** mode ``-fork=N`` (where ``N`` is the number of parallel jobs)
enables oom-, timeout-, and crash-resistant
fuzzing with separate processes (using ``fork-exec``, not just ``fork``).
The top libFuzzer process will not do any fuzzing itself, but will
spawn up to ``N`` concurrent child processes providing them
small random subsets of the corpus. After a child exits, the top process
merges the corpus generated by the child back to the main corpus.
Related flags:
``-ignore_ooms``
True by default. If an OOM happens during fuzzing in one of the child processes,
the reproducer is saved on disk, and fuzzing continues.
``-ignore_timeouts``
True by default, same as ``-ignore_ooms``, but for timeouts.
``-ignore_crashes``
False by default, same as ``-ignore_ooms``, but for all other crashes.
The plan is to eventually replace ``-jobs=N`` and ``-workers=N`` with ``-fork=N``.
Resuming merge
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