As with Linux placce the Counters array in the __libfuzzer_extra_counters
section. This fixes the test on FreeBSD.
Reviewed by: vitalybuka
Differential Revision: https://reviews.llvm.org/D125902
3bd112c720 fixed the fuzzing test on Linux, which, after
https://reviews.llvm.org/D125933, has one less branch. Turns out, on
Windows, that it still has the extra branch. I'm guessing that's because
exit() isn't known to be noreturn on Windows or something.
Either way, just make the test more tolerant.
https://reviews.llvm.org/D125933 improved some of LLVM's handling of
binary ORs, which meant we have one less conditional branch, because the
'if (Size > 5 && Data[5] == 'R')' and 'if (bits == 63)' branches are now
correctly folded.
This halves the size of LargeTest, dropping time to compile this
file locally from 14s to 5.5s. Hopefully this will also fix the
persistent timeouts in pre-merge checks.
Differential Revision: https://reviews.llvm.org/D124237
This clarifies that this is an LLVM specific variable and avoids
potential conflicts with other projects.
Differential Revision: https://reviews.llvm.org/D119918
These tests appear to be causing timeouts on our silent
Thumbv7 bot: https://lab.llvm.org/staging/#/builders/162/builds/260
It is possible they would complete given enough time. value-profile-switch
seems to take a long time even on a powerful Armv8 machine.
This reverts commit 640beb38e7.
That commit caused performance degradtion in Quicksilver test QS:sGPU and a functional test failure in (rocPRIM rocprim.device_segmented_radix_sort).
Reverting until we have a better solution to s_cselect_b64 codegen cleanup
Change-Id: Ibf8e397df94001f248fba609f072088a46abae08
Reviewed By: kzhuravl
Differential Revision: https://reviews.llvm.org/D115960
Change-Id: Id169459ce4dfffa857d5645a0af50b0063ce1105
The test has been flaky for years, and I think we should remove it to
eliminate noise on the buildbot.
Neither me nor dokyungs have been able to fully deflake the test, and it
tests a non-default Entropic flag.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D115453
Entropic scheduling with exec-time option can be misled, if inputs
on the right path to become crashing inputs accidentally take more
time to execute before it's added to the corpus. This patch, by letting
more of such inputs added to the corpus (four inputs of size 7 to 10,
instead of a single input of size 2), reduces possibilities of being
influenced by timing flakiness.
A longer-term fix could be to reduce timing flakiness in the fuzzer;
one way could be to execute inputs multiple times and take average of
their execution time before they are added to the corpus.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D113544
I found that the initial corpus allocation of fork mode has certain defects.
I designed a new initial corpus allocation strategy based on size grouping.
This method can give more energy to the small seeds in the corpus and
increase the throughput of the test.
Fuzzbench data (glibfuzzer is -fork_corpus_groups=1):
https://www.fuzzbench.com/reports/experimental/2021-08-05-parallel/index.html
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D105084
Extend the existing single-pass algorithm for `Merger::Merge` with an algorithm that gives better results. This new implementation can be used with a new **set_cover_merge=1** flag.
This greedy set cover implementation gives a substantially smaller final corpus (40%-80% less testcases) while preserving the same features/coverage. At the same time, the execution time penalty is not that significant (+50% for ~1M corpus files and far less for smaller corpora). These results were obtained by comparing several targets with varying size corpora.
Change `Merger::CrashResistantMergeInternalStep` to collect all features from each file and not just unique ones. This is needed for the set cover algorithm to work correctly. The implementation of the algorithm in `Merger::SetCoverMerge` uses a bitvector to store features that are covered by a file while performing the pass. Collisions while indexing the bitvector are ignored similarly to the fuzzer.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D105284
This fails with:
/tmp/FlagsTest-5761bc.o: In function `sancov.module_ctor_8bit_counters':
FlagsTest.cpp:(.text.sancov.module_ctor_8bit_counters[sancov.module_ctor_8bit_counters]+0x14): undefined reference to `__start___sancov_cntrs'
FlagsTest.cpp:(.text.sancov.module_ctor_8bit_counters[sancov.module_ctor_8bit_counters]+0x18): undefined reference to `__stop___sancov_cntrs'
<...>
Since https://reviews.llvm.org/D107374. However the changes
there don't seem to be the real fault so xfail while I look into it.
- Enable extra coverage counters on Windows.
- Update extra_counters.test to run on Windows also.
- Update TableLookupTest.cpp to include the required pragma/declspec for the extra coverage counters.
Patch By: MichaelSquires
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D106676
This reverts commit 52aeacfbf5.
There isn't full agreement on a path forward yet, but there is agreement that
this shouldn't land as-is. See discussion on https://reviews.llvm.org/D105338
Also reverts unreviewed "[clang] Improve `-Wnull-dereference` diag to be more in-line with reality"
This reverts commit f4877c78c0.
And all the related changes to tests:
This reverts commit 9a0152799f.
This reverts commit 3f7c9cc274.
This reverts commit 329f8197ef.
This reverts commit aa9f58cc2c.
This reverts commit 2df37d5ddd.
This reverts commit a72a441812.
This change introduces libMutagen/libclang_rt.mutagen.a as a subset of libFuzzer/libclang_rt.fuzzer.a. This library contains only the fuzzing strategies used by libFuzzer to produce new test inputs from provided inputs, dictionaries, and SanitizerCoverage feedback.
Most of this change is simply moving sections of code to one side or the other of the library boundary. The only meaningful new code is:
* The Mutagen.h interface and its implementation in Mutagen.cpp.
* The following methods in MutagenDispatcher.cpp:
* UseCmp
* UseMemmem
* SetCustomMutator
* SetCustomCrossOver
* LateInitialize (similar to the MutationDispatcher's original constructor)
* Mutate_AddWordFromTORC (uses callbacks instead of accessing TPC directly)
* StartMutationSequence
* MutationSequence
* DictionaryEntrySequence
* RecommendDictionary
* RecommendDictionaryEntry
* FuzzerMutate.cpp (which now justs sets callbacks and handles printing)
* MutagenUnittest.cpp (which adds tests of Mutagen.h)
A note on performance: This change was tested with a 100 passes of test/fuzzer/LargeTest.cpp with 1000 runs per pass, both with and without the change. The running time distribution was qualitatively similar both with and without the change, and the average difference was within 30 microseconds (2.240 ms/run vs 2.212 ms/run, respectively). Both times were much higher than observed with the fully optimized system clang (~0.38 ms/run), most likely due to the combination of CMake "dev mode" settings (e.g. CMAKE_BUILD_TYPE="Debug", LLVM_ENABLE_LTO=OFF, etc.). The difference between the two versions built similarly seems to be "in the noise" and suggests no meaningful performance degradation.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D102447
These have been broken by https://reviews.llvm.org/D104494.
However, `lib/fuzzer/dataflow/` is unused (?) so addressing this is not a priority.
Added TODOs to re-enable them in the future.
Reviewed By: stephan.yichao.zhao
Differential Revision: https://reviews.llvm.org/D104568
Complete support for fast8:
- amend shadow size and mapping in runtime
- remove fast16 mode and -dfsan-fast-16-labels flag
- remove legacy mode and make fast8 mode the default
- remove dfsan-fast-8-labels flag
- remove functions in dfsan interface only applicable to legacy
- remove legacy-related instrumentation code and tests
- update documentation.
Reviewed By: stephan.yichao.zhao, browneee
Differential Revision: https://reviews.llvm.org/D103745
This change introduces libMutagen/libclang_rt.mutagen.a as a subset of libFuzzer/libclang_rt.fuzzer.a. This library contains only the fuzzing strategies used by libFuzzer to produce new test inputs from provided inputs, dictionaries, and SanitizerCoverage feedback.
Most of this change is simply moving sections of code to one side or the other of the library boundary. The only meaningful new code is:
* The Mutagen.h interface and its implementation in Mutagen.cpp.
* The following methods in MutagenDispatcher.cpp:
* UseCmp
* UseMemmem
* SetCustomMutator
* SetCustomCrossOver
* LateInitialize (similar to the MutationDispatcher's original constructor)
* Mutate_AddWordFromTORC (uses callbacks instead of accessing TPC directly)
* StartMutationSequence
* MutationSequence
* DictionaryEntrySequence
* RecommendDictionary
* RecommendDictionaryEntry
* FuzzerMutate.cpp (which now justs sets callbacks and handles printing)
* MutagenUnittest.cpp (which adds tests of Mutagen.h)
A note on performance: This change was tested with a 100 passes of test/fuzzer/LargeTest.cpp with 1000 runs per pass, both with and without the change. The running time distribution was qualitatively similar both with and without the change, and the average difference was within 30 microseconds (2.240 ms/run vs 2.212 ms/run, respectively). Both times were much higher than observed with the fully optimized system clang (~0.38 ms/run), most likely due to the combination of CMake "dev mode" settings (e.g. CMAKE_BUILD_TYPE="Debug", LLVM_ENABLE_LTO=OFF, etc.). The difference between the two versions built similarly seems to be "in the noise" and suggests no meaningful performance degradation.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D102447
Address sanitizer can detect stack exhaustion via its SEGV handler, which is
executed on a separate stack using the sigaltstack mechanism. When libFuzzer is
used with address sanitizer, it installs its own signal handlers which defer to
those put in place by the sanitizer before performing additional actions. In the
particular case of a stack overflow, the current setup fails because libFuzzer
doesn't preserve the flag for executing the signal handler on a separate stack:
when we run out of stack space, the operating system can't run the SEGV handler,
so address sanitizer never reports the issue. See the included test for an
example.
This commit fixes the issue by making libFuzzer preserve the SA_ONSTACK flag
when installing its signal handlers; the dedicated signal-handler stack set up
by the sanitizer runtime appears to be large enough to support the additional
frames from the fuzzer.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D101824
This test was found to fail for some of our downstream builds, on
computers where python was not on the default $PATH. Therefore
add a %python substitution to use sys.executable, based on similar
solutions for python calls in tests elsewhere in LLVM.
Differential Revision: https://reviews.llvm.org/D96799
Adds a new option, `handle_winexcept` to try to intercept uncaught
Visual C++ exceptions on Windows. On Linux, such exceptions are handled
implicitly by `std::terminate()` raising `SIBABRT`. This option brings the
Windows behavior in line with Linux.
Unfortunately this exception code is intentionally undocumented, however
has remained stable for the last decade. More information can be found
here: https://devblogs.microsoft.com/oldnewthing/20100730-00/?p=13273
Reviewed By: morehouse, metzman
Differential Revision: https://reviews.llvm.org/D89755
-print_full_coverage=1 produces a detailed branch coverage dump when run on a single file.
Uses same infrastructure as -print_coverage flag, but prints all branches (regardless of coverage status) in an easy-to-parse format.
Usage: For internal use with machine learning fuzzing models which require detailed coverage information on seed files to generate mutations.
Differential Revision: https://reviews.llvm.org/D85928
The test started to consistently fail after unrelated
2ffaa9a173.
Even before the patch it was possible to fail the test,
e.g. -seed=1660180256 on my workstation.
Also this checks do not look related to strcmp.
Andrew Turner
gtt1995