LLVM defines `PTHREAD_LIB` which is used by AddLLVM.cmake and various projects
to correctly link the threading library when needed. Unfortunately
`PTHREAD_LIB` is defined by LLVM's `config-ix.cmake` file which isn't installed
and therefore can't be used when configuring out-of-tree builds. This causes
such builds to fail since `pthread` isn't being correctly linked.
This patch attempts to fix that problem by renaming and exporting
`LLVM_PTHREAD_LIB` as part of`LLVMConfig.cmake`. I renamed `PTHREAD_LIB`
because It seemed likely to cause collisions with downstream users of
`LLVMConfig.cmake`.
llvm-svn: 294690
Replace weak aliases with dynamic loading.
Weak aliases were generating some problems when linking for MT on Windows. For
MT, compiler-rt's libraries are statically linked to the main executable the
same than libFuzzer, so if we use weak aliases, we are providing two different
default implementations for the same weak function and the linker fails.
In this diff I re implement ExternalFunctions() using dynamic loading, so it
works in both cases (MD and MT). Also, dynamic loading is simpler, since we are
not defining any auxiliary external function, and we don't need to deal with
weak aliases.
This is equivalent to the implementation using dlsym(RTLD_DEFAULT, FnName) for
Posix.
Differential revision: https://reviews.llvm.org/D29751
llvm-svn: 294687
In this diff, I add stubs for shared memory on Windows. Now we can compile and
use libFuzzer without support for shared memory.
Differential Revision: https://reviews.llvm.org/D29544
llvm-svn: 294376
This resubmits r288529, which was resubmitted because it broke a
fuzzer bot. According to kcc@ the test that broke was flakey
and it is unlikely to be a result of this patch.
llvm-svn: 288549
Windows doesn't really support weak aliases, but with some
linker magic we can get something that's pretty close on
Windows. This introduces an interface to accessing weakly
aliased symbols that will work on any platform. Linker
magic changes to come in a separate patch.
Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27235
llvm-svn: 288530
Pave the way for separating out platform specific
utility functions into separate files.
Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27234
llvm-svn: 288529
This patch moves some posix specific file i/o code into a new
file, FuzzerIOPosix.cpp, and provides implementations for these
functions on Windows in FuzzerIOWindows.cpp. This is another
incremental step towards getting libfuzzer working on Windows,
although it still should not be expected to be fully working.
Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27233
llvm-svn: 288275
The original `ExecuteCommand()` called `system()` from the C library.
The C library implementation of this on macOS contains a mutex which
serializes calls to `system()`. This prevented the `-jobs=` flag
from running copies of the fuzzing binary in parallel which is
the opposite of what is intended.
To fix this on macOS an alternative implementation of `ExecuteCommand()`
is provided that can be used concurrently. This is provided in
`FuzzerUtilDarwin.cpp` which is guarded to only compile code on Apple
platforms. The existing implementation has been moved to a new file
`FuzzerUtilLinux.cpp` which is guarded to only compile code on Linux.
This commit includes a simple test to check that LibFuzzer is being
executed in parallel when requested.
Differential Revision: https://reviews.llvm.org/D22742
llvm-svn: 278544
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
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
Newer versions of libstdc++ (4.9+), as well as libc++, depend directly on
libpthread from the standard library headers, so libfuzzer needs to declare
a standard library dependency.
llvm-svn: 255745
Summary:
This adds a SHA1 implementation taken from public domain code.
The change is trivial, but as it involves third-party code I'd like
a second pair of eyes before commit.
LibFuzzer can not use SHA1 from openssl because openssl may not be available
and because we may be fuzzing openssl itself.
Using sha1sum via a pipe is too slow.
Test Plan: n/a
Reviewers: chandlerc
Reviewed By: chandlerc
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D9733
llvm-svn: 237400
Summary:
This adds a simple DFSan-based (i.e. taint-guided) fuzzer mutator,
see the comments for details.
Test Plan: a test added
Reviewers: samsonov, pcc
Reviewed By: samsonov, pcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8669
llvm-svn: 233613
Summary: Add test targets and the lit-style runner.
Test Plan: Run the tests on bot.
Reviewers: samsonov
Reviewed By: samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7217
llvm-svn: 227389
Summary:
A simple genetic in-process coverage-guided fuzz testing library.
I've used this fuzzer to test clang-format
(it found 12+ bugs, thanks djasper@ for the fixes!)
and it may also help us test other parts of LLVM.
So why not keep it in the LLVM repository?
I plan to add the cmake build rules later (in a separate patch, if that's ok)
and also add a clang-format-fuzzer target.
See README.txt for details.
Test Plan: Tests will follow separately.
Reviewers: djasper, chandlerc, rnk
Reviewed By: rnk
Subscribers: majnemer, ygribov, dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D7184
llvm-svn: 227252
Kostya Serebryany