Summary:
[libFuzzer] Enable afl_driver to append stderr to a user specified file.
Append stderr of afl_driver to the file specified by the environmental variable
AFL_DRIVER_STDERR_DUPLICATE_FILENAME if it is set. This lets users see outputs
on crashes without rerunning crashing test cases (which won't work for crashes
that are difficult to reproduce). Before this patch, stderr would only be sent to afl-fuzz
and users would have no way of seeing it.
Reviewers: llvm-commits, aizatsky, kcc, vitalybuka
Subscribers: vitalybuka
Differential Revision: http://reviews.llvm.org/D21194
llvm-svn: 272858
The ``FuzzerMutate.ShuffleBytes2`` unit test was failing on
OSX due to the implementation of ``std::random_shuffle()``
being different between libcxx and libstdc++.
@kcc has decided (see http://reviews.llvm.org/D21218) it is acceptable
for there to be different mutation behavior on different platforms so
this commit just adjusts the test to perform the minimum number of
iterations (that is a power of 2) to see all the mutations the unit test
is looking for.
Differential Revision: http://reviews.llvm.org/D21359
llvm-svn: 272743
Summary:
[libFuzzer] Enable afl_driver to append stderr to a user specified file.
Append stderr of afl_driver to the file specified by the environmental variable
AFL_DRIVER_STDERR_DUPLICATE_FILENAME if it is set. This lets users see outputs
on crashes without rerunning crashing test cases (which won't work for crashes
that are difficult to reproduce). Before this patch, stderr would only be sent to afl-fuzz
and users would have no way of seeing it.
Reviewers: llvm-commits, aizatsky, kcc, vitalybuka
Subscribers: vitalybuka
Differential Revision: http://reviews.llvm.org/D21194
llvm-svn: 272706
On OSX this test sometimes fails due to the
``LLVMFuzzer-FullCoverageSetTest-TracePC`` program going over the
default 2GiB memory limit. This shouldn't be happening and needs
investigating. For now just disable the test so we can set up an
OSX buildbot.
Differential Revision: http://reviews.llvm.org/D21319
llvm-svn: 272696
The tests in ``fuzzer-traces-hooks.test`` only work on Linux because calls to hooks
(e.g. ``__sanitizer_weak_hook_memcmp()``) from inside the sanitizer
runtime are only implemented on Linux. Therefore these tests are set to
only run on Linux.
Differential Revision: http://reviews.llvm.org/D21253
llvm-svn: 272600
This fixes the following unit tests:
FuzzerDictionary.ParseOneDictionaryEntry
FuzzerDictionary.ParseDictionaryFile
The issue appears to be mixing non-ASan-ified code (LibFuzzer) and
ASan-ified code (the unittest) as the tests would pass fine if
everything was built with ASan enabled.
I believe the issue is that different implementations of std::vector<>
are being used in LibFuzzer and outside LibFuzzer (in the unittests).
For Libcxx (I've not seen the issue manifest for libstdc++) we can disable
the ASanified std::vector<> by definining the ``_LIBCPP_HAS_NO_ASAN`` macro.
Doing this fixes the tests on OSX.
Differential Revision: http://reviews.llvm.org/D21049
llvm-svn: 272374
This fixes linking problems on OSX.
Unfortunately it turns out we need to use an instance of the
``fuzzer::ExternalFunctions`` object in several places so this
commit also replaces all instances with a single global instance.
It also turns out initializing a global ``fuzzer::ExternalFunctions``
before main is entered (i.e. letting the object be initialised by the
global initializers) is not safe (on OSX the call to ``Printf()`` in the
CTOR crashes if it is called from a global initializer) so we instead
have a global ``fuzzer::ExternalFunctions*`` and initialize it inside
``FuzzerDriver()``.
Multiple unit tests depend also depend on the
``fuzzer::ExternalFunctions*`` global so a ``main()`` function has been
added that initializes it before running any tests.
Differential Revision: http://reviews.llvm.org/D20943
llvm-svn: 272072
This is necessary because the existing fuzzer-oom.test was Linux
specific due to its use of __sanitizer_print_memory_profile() which
is only available on Linux right now and so the test would fail on OSX.
Differential Revision: http://reviews.llvm.org/D20977
llvm-svn: 272061
Summary:
The option is very useful for testing, plus I intend to measure
its effect on fuzzer effectiveness.
Differential Revision: http://reviews.llvm.org/D21084
llvm-svn: 272035
Calls to this function are currently injected by the
``SanitizerCoverageModule`` pass when the both the ``indirect-calls``
and ``trace-pc`` sanitizer coverage options are enabled and the code
being instrumented has indirect calls. Previously because LibFuzzer did
not define this function this would lead to link errors when building
some of the tests on OSX.
Differential Revision: http://reviews.llvm.org/D20946
llvm-svn: 271938
This fixes a broken part of the build on OSX as the dataflow sanitizer is not supported
on OSX yet.
Differential Revision: http://reviews.llvm.org/D20894
llvm-svn: 271492
The motivation for this change is to fix linking issues on OSX.
However this only partially fixes linking issues (the uninstrumented
tests and a few others won't succesfully link yet).
This change introduces a struct of function pointers
(``fuzzer::ExternalFuntions``) which when initialised will point to the
optional functions if they are available. Currently these
``LLVMFuzzerInitialize`` and ``LLVMFuzzerCustomMutator`` functions.
Two implementations of ``fuzzer::ExternalFunctions`` constructor are
provided one for Linux and one for OSX.
The OSX implementation uses ``dlsym()`` because the prior implementation
using weak symbols does not work unless the additional flags are passed
to the linker.
The Linux implementation continues to use weak symbols because the
``dlsym()`` approach does not work unless additional flags are passed
to the linker.
Differential Revision: http://reviews.llvm.org/D20741
llvm-svn: 271491
Add a new CMake function (``add_libfuzzer_test()``) to simplify
declaration of executables for testing LibFuzzer and use it to
reorganise how tests are declared.
Note that configuration of the lit configuration files has been moved
as late as possible because we are going to need to disable some tests
for some platforms and we will need to propagate this information into
the lit configuration.
Note the code for custom mains was removed because no tests are
currently written for this and Kostya seems happy to remove this.
Differential Revision: http://reviews.llvm.org/D20706
llvm-svn: 270958
Previously CMake would successfully configure and compile (with warnings
about ``-fsanitize-coverage=...`` being unused) but the tests LibFuzzer
tests would fail.
Differential Revision: http://reviews.llvm.org/D20662
llvm-svn: 270913
Previously the flags were only being set correctly when the
build type was "Release". Now the build should work properly
for all the supported build types. When building libFuzzer
the optimization level respects whatever is used for the
rest of LLVM but for the LibFuzzer tests we force -O0.
Differential Revision: http://reviews.llvm.org/D20558
llvm-svn: 270912
The ``nprocs`` command does not exist under Mac OSX so use
``sysctl`` instead on that platform.
Whilst I'm here
* Use ``pclose()`` instead of ``fclose()`` which the ``popen()``
documentation says should be used.
* Check for errors that were previously unhandled.
Differential Revision: http://reviews.llvm.org/D20409
llvm-svn: 270172
Work around crashes in ``__sanitizer_malloc_hook()`` under Mac OSX.
Under Mac OSX we intercept calls to malloc before thread local
storage is initialised leading to a crash when accessing
``AllocTracer``. To workaround this ``AllocTracer`` is only accessed
in the hook under Linux. For symmetry ``__sanitizer_free_hook()``
is also modified in the same way.
To support this change a set of new macros
LIBFUZZER_LINUX and LIBFUZZER_APPLE has been defined which can be
used to check the target being compiled for.
Differential Revision: http://reviews.llvm.org/D20402
llvm-svn: 270145
