Summary:
1. Do not create DFSan labels for the bytes which we do not trace. This is where we run out of labels at the first place.
2. When dumping the traces on the disk, make sure to offset the label identifiers by the number of the first byte in the trace range.
3. For the last label, make sure to write it at the last position of the trace bit string, as that label represents the input size, not any particular byte.
Also fixed the bug with division in python which I've introduced when migrated the scripts to Python3 (`//` is required for integral division).
Otherwise, the scripts are wasting too much time unsuccessfully trying to
collect and process traces from the long inputs. For more context, see
https://github.com/google/oss-fuzz/issues/1632#issuecomment-481761789
Reviewers: kcc
Reviewed By: kcc
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D60538
llvm-svn: 358311
Summary:
Before this change, MutateWithMask used to assert that Mask should be
of sufficient length (>= Size of the input). However, in real cases we may have
inputs that are longer than the Mask they have inherited from the based inputs.
Reviewers: kcc, morehouse
Reviewed By: kcc
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D60571
llvm-svn: 358207
Summary:
In case the current corpus input doesn't have bytes going into the
focus function, MutateWithMask is useless and may fail gently, allowing the
default mutation routine happen, rather than crashing on an assertion.
For more context and the initial fix suggestion, see:
https://github.com/google/oss-fuzz/issues/1632#issuecomment-481862879
Reviewers: kcc, morehouse
Reviewed By: kcc
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D60567
llvm-svn: 358190
Summary:
When using libfuzzer on Windows, in the contents of a crash sample, bytes that can be mistaken for a \n are replaced by a \r\n sequence. As a consequence, crashes are not reproducible. This patch will open files in binary mode to fix this issue. The patch does not affect POSIX systems.
Patch by tuktuk
Reviewers: kcc, vitalybuka
Reviewed By: vitalybuka
Subscribers: dexonsmith, jdoerfert, llvm-commits, #sanitizers
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D60008
llvm-svn: 357807
Summary:
This fixes inconsistent symbol visibility. This shows up as a linker
warning if r336238 (43f633564e338a6dde83d49a48e5bfcbfdce292c) is
reverted.
```
ld: warning: direct access in function 'fuzzer::CleanseCrashInput(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, fuzzer::fuzzer_allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, fuzzer::FuzzingOptions const&)' from file '/Volumes/data/dev/llvm/upstream/master/builds/projects/compiler-rt/lib/fuzzer/tests/libRTFuzzerTest.x86_64.a(FuzzerDriver.cpp.o)' to global weak symbol 'fuzzer::Command::ignoreRemainingArgs()::kIgnoreRemaining' from file 'FuzzerTestObjects.FuzzerUnittest.cpp.x86_64.o' means the weak symbol cannot be overridden
at runtime. This was likely caused by different translation units being compiled with different visibility settings.
```
r336238 just hid the issue rather than fixing the real issue. On macOS
and other platforms we usually compile with `-fvisibility=hidden` but
the unit tests were compiled without this flag.
Reviewers: george.karpenkov, kubamracek, kcc, yln
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D58055
llvm-svn: 355143
Summary:
Port libFuzzer's fork mode to Windows.
Implement Windows versions of MkDir, RmDir, and IterateDirRecursive to do this.
Don't print error messages under new normal uses of FileSize (on a non-existent file).
Implement portable way of piping output to /dev/null.
Fix test for Windows and comment fork-sigusr.test on why it won't be ported to Win.
Reviewers: zturner
Reviewed By: zturner
Subscribers: kcc, zturner, jdoerfert, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D58513
llvm-svn: 355019
Summary:
When running the standalone main on a large corpus, I eventually get a
EMFILE error ("Too many open files").
Patch by Paul Chaignon
Reviewers: kcc, vitalybuka
Reviewed By: vitalybuka
Subscribers: lebedev.ri, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D58622
llvm-svn: 354918
According to the logs and local debugging there were two issues:
1) tsan tests listed libc++.a before the source file. That's usually
ok for shared libraries, but the linker will not add symbols from
a static library unless needed at that time. As a result the tests
that rely upon symbols from the library (and not only include the
headers) had undefined references.
To solve this I'm adding a new substitution %link_libcxx_tsan which
expands to libc++.a if available.
2) The target Fuzzer-x86_64-Test linked in SANITIZER_TEST_CXX_LIBRARIES
which defaults to -lstdc++. This resulted in error messages like
hidden symbol '_ZdlPv' is not defined locally
hidden symbol '_Znwm' is not defined locally
when using GNU gold (ld.bfd and lld are fine). Removing the linkage
is fine because we build a custom libc++ for that purpose.
llvm-svn: 354231
This changes add_custom_libcxx to also build libcxxabi and merges
the two into a static and hermetic library.
There are multiple advantages:
1) The resulting libFuzzer doesn't expose C++ internals and looks
like a plain C library.
2) We don't have to manually link in libstdc++ to provide cxxabi.
3) The sanitizer tests cannot interfere with an installed version
of libc++.so in LD_LIBRARY_PATH.
Differential Revision: https://reviews.llvm.org/D58013
llvm-svn: 354212
Add missed value "libcxxabi" and introduce SANITIZER_TEST_CXX for linking
unit tests. This needs to be a full C++ library and cannot be libcxxabi.
Recommit r354132 which I reverted in r354153 because it broke a sanitizer
bot. This was because of the "fixes" for pthread linking, so I've removed
these changes.
Differential Revision: https://reviews.llvm.org/D58012
llvm-svn: 354198
Add missed value "libcxxabi" and introduce SANITIZER_TEST_CXX for linking
unit tests. This needs to be a full C++ library and cannot be libcxxabi.
Differential Revision: https://reviews.llvm.org/D58012
llvm-svn: 354132
The __sanitizer_acquire_crash_state function has int return type, but the
fuzzer's external function definitions give it bool.
Places where __sanitizer_acquire_crash_state is declared:
include/sanitizer_common/sanitizer_interface_defs.h
lib/sanitizer_common/sanitizer_interface_internal.h
lib/sanitizer_common/sanitizer_common.cc
lib/fuzzer/FuzzerExtFunctions.def (this is the only bool)
llvm-svn: 353596
Summary:
Use `_write` instead of the deprecated alias `write` on Windows.
Also, remove comment saying RawPrint is untested on Windows.
Reviewers: vitalybuka
Reviewed By: vitalybuka
Subscribers: vitalybuka
Differential Revision: https://reviews.llvm.org/D57589
llvm-svn: 353108
Summary:
Use RawPrint instead of Printf for instrumentation warning because
Printf doesn't work on Win when instrumentation is being
initialized (since OutputFile is not yet initialized).
Reviewers: kcc
Reviewed By: kcc
Differential Revision: https://reviews.llvm.org/D57531
llvm-svn: 352789
Summary:
Set default `ASAN_OPTIONS` when running libFuzzer tests. This allows us
to remove special casing in code for Darwin where we usually pass
`abort_on_error=0` to override platform defaults for tests.
A previous commit changed the code to make the tests pass:
7764a04af0
Adapted a few tests to use `%env_asan_opts=` instead of directly setting
the environment variable.
rdar://problem/47515276
Reviewers: kcc, george.karpenkov
Differential Revision: https://reviews.llvm.org/D57465
llvm-svn: 352711
