[libFuzzer] Extend the fuzz target intarface to allow -1 return value.

With this change, fuzz targets may choose to return -1
to indicate that the input should not be added to the corpus
regardless

[libFuzzer] Extend the fuzz target intarface to allow -1 return value.

With this change, fuzz targets may choose to return -1
to indicate that the input should not be added to the corpus
regardless of the coverage it generated.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D128749

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[libFuzzer] Update InputInfo.TimeOfUnit when replacing it in the corpus.

Previously, when the fuzzing loop replaced an input in the corpus, it didn't update the execution time of the input. Therefor

[libFuzzer] Update InputInfo.TimeOfUnit when replacing it in the corpus.

Previously, when the fuzzing loop replaced an input in the corpus, it didn't update the execution time of the input. Therefore, some schedulers (e.g. Entropic) would adjust weights based on the incorrect execution time.

This patch updates the execution time of the input when replacing it.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D111479

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[libFuzzer] replace Vector/Set with std::vector/std::set. The custom names are not required any more since we now build with a private version of libc++. Fix some of the 81+ character lines. Mechanic

[libFuzzer] replace Vector/Set with std::vector/std::set. The custom names are not required any more since we now build with a private version of libc++. Fix some of the 81+ character lines. Mechanical change, NFC expected.

[libFuzzer] replace Vector/Set with std::vector/std::set.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D107374

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Revert "Refactor mutation strategies into a standalone library"

This reverts commit 361f742f168de0f0f256802a329c19d081615d0d.

Refactor mutation strategies into a standalone library

This change introduces libMutagen/libclang_rt.mutagen.a as a subset of libFuzzer/libclang_rt.fuzzer.a. This library contains only the fuzzing s

Refactor mutation strategies into a standalone library

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

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Revert "Refactor mutation strategies into a standalone library"

This reverts commit c4a41cd77c15c2905ac74beeec09f8343a65a549 due to
buildbot failure.

Refactor mutation strategies into a standalone library

This change introduces libMutagen/libclang_rt.mutagen.a as a subset of libFuzzer/libclang_rt.fuzzer.a. This library contains only the fuzzing s

Refactor mutation strategies into a standalone library

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

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[fuzzer] Print reloaded file paths

In order to integrate libFuzzer with a dynamic symbolic execution tool
Sydr we need to print loaded file paths.

Reviewed By: morehouse

Differential Revision: htt

[fuzzer] Print reloaded file paths

In order to integrate libFuzzer with a dynamic symbolic execution tool
Sydr we need to print loaded file paths.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D100303

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[libFuzzer] Use macro instead of __attribute__.

This should fix the Windows buildbot errors.

[libFuzzer] Add attribute noinline on Fuzzer::ExecuteCallback().

The inlining of this function needs to be disabled as it is part of the
inpsected stack traces. It's string representation will look

[libFuzzer] Add attribute noinline on Fuzzer::ExecuteCallback().

The inlining of this function needs to be disabled as it is part of the
inpsected stack traces. It's string representation will look different
depending on if it was inlined or not which will cause it's string comparison
to fail.

When it was inlined in only one of the two execution stacks,
minimize_two_crashes.test failed on SystemZ. For details see
https://bugs.llvm.org/show_bug.cgi?id=49152.

Reviewers: Ulrich Weigand, Matt Morehouse, Arthur Eubanks

Differential Revision: https://reviews.llvm.org/D97975

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[crt][fuzzer] Fix up various numeric conversions

Attempting to build a standalone libFuzzer in Fuchsia's default toolchain for the purpose of cross-compiling the unit tests revealed a number of not

[crt][fuzzer] Fix up various numeric conversions

Attempting to build a standalone libFuzzer in Fuchsia's default toolchain for the purpose of cross-compiling the unit tests revealed a number of not-quite-proper type conversions. Fuchsia's toolchain include `-std=c++17` and `-Werror`, among others, leading to many errors like `-Wshorten-64-to-32`, `-Wimplicit-float-conversion`, etc.

Most of these have been addressed by simply making the conversion explicit with a `static_cast`. These typically fell into one of two categories: 1) conversions between types where high precision isn't critical, e.g. the "energy" calculations for `InputInfo`, and 2) conversions where the values will never reach the bits being truncated, e.g. `DftTimeInSeconds` is not going to exceed 136 years.

The major exception to this is the number of features: there are several places that treat features as `size_t`, and others as `uint32_t`. This change makes the decision to cap the features at 32 bits. The maximum value of a feature as produced by `TracePC::CollectFeatures` is roughly:
(NumPCsInPCTables + ValueBitMap::kMapSizeInBits + ExtraCountersBegin() - ExtraCountersEnd() + log2(SIZE_MAX)) * 8

It's conceivable for extremely large targets and/or extra counters that this limit could be reached. This shouldn't break fuzzing, but it will cause certain features to collide and lower the fuzzers overall precision. To address this, this change adds a warning to TracePC::PrintModuleInfo about excessive feature size if it is detected, and recommends refactoring the fuzzer into several smaller ones.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D97992

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[libFuzzer] Added -print_full_coverage flag.

-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 a

[libFuzzer] Added -print_full_coverage flag.

-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

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[libfuzzer] Reduce default verbosity when printing large mutation sequences

When using a custom mutator (e.g. thrift mutator, similar to LPM)
that calls back into libfuzzer's mutations via `LLVMFuzz

[libfuzzer] Reduce default verbosity when printing large mutation sequences

When using a custom mutator (e.g. thrift mutator, similar to LPM)
that calls back into libfuzzer's mutations via `LLVMFuzzerMutate`, the mutation
sequences needed to achieve new coverage can get prohibitively large.

Printing these large sequences has two downsides:

1) It makes the logs hard to understand for a human.
2) The performance cost slows down fuzzing.

In this patch I change the `PrintMutationSequence` function to take a max
number of entries, to achieve this goal. I also update `PrintStatusForNewUnit`
to default to printing only 10 entries, in the default verbosity level (1),
requiring the user to set verbosity to 2 if they want the full mutation
sequence.

For our use case, turning off verbosity is not an option, as that would also
disable `PrintStats()` which is very useful for infrastructure that analyzes
the logs in realtime. I imagine most users of libfuzzer always want those logs
in the default.

I built a fuzzer locally with this patch applied to libfuzzer.

When running with the default verbosity, I see logs like this:

#65 NEW cov: 4799 ft: 10443 corp: 41/1447Kb lim: 64000 exec/s: 1 rss: 575Mb L: 28658/62542 MS: 196 Custom-CrossOver-ChangeBit-EraseBytes-ChangeBit-ChangeBit-ChangeBit-CrossOver-ChangeBit-CrossOver- DE: "\xff\xff\xff\x0e"-"\xfe\xff\xff\x7f"-"\xfe\xff\xff\x7f"-"\x17\x00\x00\x00\x00\x00\x00\x00"-"\x00\x00\x00\xf9"-"\xff\xff\xff\xff"-"\xfa\xff\xff\xff"-"\xf7\xff\xff\xff"-"@\xff\xff\xff\xff\xff\xff\xff"-"E\x00"-
#67 NEW cov: 4810 ft: 10462 corp: 42/1486Kb lim: 64000 exec/s: 1 rss: 577Mb L: 39823/62542 MS: 135 Custom-CopyPart-ShuffleBytes-ShuffleBytes-ChangeBit-ChangeBinInt-EraseBytes-ChangeBit-ChangeBinInt-ChangeBit- DE: "\x01\x00\x00\x00\x00\x00\x01\xf1"-"\x00\x00\x00\x07"-"\x00\x0d"-"\xfd\xff\xff\xff"-"\xfe\xff\xff\xf4"-"\xe3\xff\xff\xff"-"\xff\xff\xff\xf1"-"\xea\xff\xff\xff"-"\x00\x00\x00\xfd"-"\x01\x00\x00\x05"-

Staring hard at the logs it's clear that the cap of 10 is applied.

When running with verbosity level 2, the logs look like the below:

#66 NEW cov: 4700 ft: 10188 corp: 37/1186Kb lim: 64000 exec/s: 2 rss: 509Mb L: 47616/61231 MS: 520 Custom-CopyPart-ChangeBinInt-ChangeBit-ChangeByte-EraseBytes-PersAutoDict-CopyPart-ShuffleBytes-ChangeBit-ShuffleBytes-CopyPart-EraseBytes-CopyPart-ChangeBinInt-CopyPart-ChangeByte-ShuffleBytes-ChangeBinInt-ShuffleBytes-ChangeBit-CMP-ShuffleBytes-ChangeBit-CrossOver-ChangeBinInt-ChangeByte-ShuffleBytes-CrossOver-EraseBytes-ChangeBinInt-InsertRepeatedBytes-PersAutoDict-InsertRepeatedBytes-InsertRepeatedBytes-CrossOver-ChangeByte-ShuffleBytes-CopyPart-ShuffleBytes-CopyPart-CrossOver-ChangeBit-ShuffleBytes-CrossOver-PersAutoDict-ChangeByte-ChangeBit-ShuffleBytes-CrossOver-ChangeByte-EraseBytes-CopyPart-ChangeBinInt-PersAutoDict-CrossOver-ShuffleBytes-CrossOver-CrossOver-EraseBytes-CrossOver-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-ChangeByte-EraseBytes-ShuffleBytes-ShuffleBytes-ChangeBit-EraseBytes-ChangeBinInt-ChangeBit-ChangeBinInt-CopyPart-EraseBytes-PersAutoDict-EraseBytes-CopyPart-ChangeBinInt-ChangeByte-CrossOver-ChangeBinInt-ShuffleBytes-PersAutoDict-PersAutoDict-ChangeBinInt-CopyPart-ChangeBinInt-CrossOver-ChangeBit-ChangeBinInt-CopyPart-ChangeByte-ChangeBit-CopyPart-CrossOver-ChangeByte-ChangeBit-ChangeByte-ShuffleBytes-CMP-ChangeBit-CopyPart-ChangeBit-ChangeByte-ChangeBinInt-PersAutoDict-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBit-ChangeBinInt-ChangeBinInt-PersAutoDict-ChangeBinInt-ChangeBinInt-ChangeByte-CopyPart-ShuffleBytes-ChangeByte-ChangeBit-ChangeByte-ChangeByte-EraseBytes-CrossOver-ChangeByte-ChangeByte-EraseBytes-EraseBytes-InsertRepeatedBytes-ShuffleBytes-CopyPart-CopyPart-ChangeBit-ShuffleBytes-PersAutoDict-ShuffleBytes-ChangeBit-ChangeByte-ChangeBit-ShuffleBytes-ChangeByte-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBit-EraseBytes-CopyPart-ChangeByte-CrossOver-EraseBytes-CrossOver-ChangeByte-ShuffleBytes-ChangeByte-ChangeBinInt-CrossOver-ChangeByte-InsertRepeatedBytes-InsertByte-ShuffleBytes-PersAutoDict-ChangeBit-ChangeByte-ChangeBit-ShuffleBytes-ShuffleBytes-CopyPart-ShuffleBytes-EraseBytes-ShuffleBytes-ShuffleBytes-CrossOver-ChangeBinInt-CopyPart-CopyPart-CopyPart-EraseBytes-EraseBytes-ChangeByte-ChangeBinInt-ShuffleBytes-CMP-InsertByte-EraseBytes-ShuffleBytes-CopyPart-ChangeBit-CrossOver-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-EraseBytes-ChangeByte-ChangeBinInt-ChangeBit-ChangeBit-ChangeByte-ShuffleBytes-PersAutoDict-PersAutoDict-CMP-ChangeBit-ShuffleBytes-PersAutoDict-ChangeBinInt-EraseBytes-EraseBytes-ShuffleBytes-ChangeByte-ShuffleBytes-ChangeBit-EraseBytes-CMP-ShuffleBytes-ChangeByte-ChangeBinInt-EraseBytes-ChangeBinInt-ChangeByte-EraseBytes-ChangeByte-CrossOver-ShuffleBytes-EraseBytes-EraseBytes-ShuffleBytes-ChangeBit-EraseBytes-CopyPart-ShuffleBytes-ShuffleBytes-CrossOver-CopyPart-ChangeBinInt-ShuffleBytes-CrossOver-InsertByte-InsertByte-ChangeBinInt-ChangeBinInt-CopyPart-EraseBytes-ShuffleBytes-ChangeBit-ChangeBit-EraseBytes-ChangeByte-ChangeByte-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBinInt-ShuffleBytes-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-ShuffleBytes-CrossOver-EraseBytes-CopyPart-CopyPart-CopyPart-ChangeBit-ShuffleBytes-ChangeByte-EraseBytes-ChangeByte-InsertRepeatedBytes-InsertByte-InsertRepeatedBytes-PersAutoDict-EraseBytes-ShuffleBytes-ChangeByte-ShuffleBytes-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeBit-CrossOver-CrossOver-ShuffleBytes-CrossOver-CopyPart-CrossOver-CrossOver-CopyPart-ChangeByte-ChangeByte-CrossOver-ChangeBit-ChangeBinInt-EraseBytes-ShuffleBytes-EraseBytes-CMP-PersAutoDict-PersAutoDict-InsertByte-ChangeBit-ChangeByte-CopyPart-CrossOver-ChangeByte-ChangeBit-ChangeByte-CopyPart-ChangeBinInt-EraseBytes-CrossOver-ChangeBit-CrossOver-PersAutoDict-CrossOver-ChangeByte-CrossOver-ChangeByte-ChangeByte-CrossOver-ShuffleBytes-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-ChangeBinInt-ChangeBinInt-ChangeBinInt-ShuffleBytes-CrossOver-ChangeBinInt-ShuffleBytes-ChangeBit-PersAutoDict-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeByte-CrossOver-ChangeBit-CopyPart-ChangeBit-ChangeBit-CopyPart-ChangeByte-PersAutoDict-ChangeBit-ShuffleBytes-ChangeByte-ChangeBit-CrossOver-ChangeByte-CrossOver-ChangeByte-CrossOver-ChangeBit-ChangeByte-ChangeBinInt-PersAutoDict-CopyPart-ChangeBinInt-ChangeBit-CrossOver-ChangeBit-PersAutoDict-ShuffleBytes-EraseBytes-CrossOver-ChangeByte-ChangeBinInt-ShuffleBytes-ChangeBinInt-InsertRepeatedBytes-PersAutoDict-CrossOver-ChangeByte-Custom-PersAutoDict-CopyPart-CopyPart-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeBit-ShuffleBytes-CrossOver-CMP-ChangeByte-CopyPart-ShuffleBytes-CopyPart-CopyPart-CrossOver-CrossOver-CrossOver-ShuffleBytes-ChangeByte-ChangeBinInt-ChangeBit-ChangeBit-ChangeBit-ChangeByte-EraseBytes-ChangeByte-ChangeBit-ChangeByte-ChangeByte-CopyPart-PersAutoDict-ChangeBinInt-PersAutoDict-PersAutoDict-PersAutoDict-CopyPart-CopyPart-CrossOver-ChangeByte-ChangeBinInt-ShuffleBytes-ChangeBit-CopyPart-EraseBytes-CopyPart-CopyPart-CrossOver-ChangeByte-EraseBytes-ShuffleBytes-ChangeByte-CopyPart-EraseBytes-CopyPart-CrossOver-ChangeBinInt-ChangeBinInt-InsertByte-ChangeBinInt-ChangeBit-ChangeByte-CopyPart-ChangeByte-EraseBytes-ChangeByte-ChangeBit-ChangeByte-ShuffleBytes-CopyPart-ChangeBinInt-EraseBytes-CrossOver-ChangeBit-ChangeBit-CrossOver-EraseBytes-ChangeBinInt-CopyPart-CopyPart-ChangeBinInt-ChangeBit-EraseBytes-InsertRepeatedBytes-EraseBytes-ChangeBit-CrossOver-CrossOver-EraseBytes-EraseBytes-ChangeByte-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeBit-ChangeByte-EraseBytes-ChangeBit-ChangeByte-ChangeByte-CrossOver-CopyPart-EraseBytes-ChangeByte-EraseBytes-ChangeByte-ShuffleBytes-ShuffleBytes-ChangeByte-CopyPart-ChangeByte-ChangeByte-ChangeBit-CopyPart-ChangeBit-ChangeBinInt-CopyPart-ShuffleBytes-ChangeBit-ChangeBinInt-ChangeBit-EraseBytes-CMP-CrossOver-CopyPart-ChangeBinInt-CrossOver-CrossOver-CopyPart-CrossOver-CrossOver-InsertByte-InsertByte-CopyPart-Custom- DE: "warn"-"\x00\x00\x00\x80"-"\xfe\xff\xff\xfb"-"\xff\xff"-"\x10\x00\x00\x00"-"\xfe\xff\xff\xff"-"\xff\xff\xff\xf6"-"U\x01\x00\x00\x00\x00\x00\x00"-"\xd9\xff\xff\xff"-"\xfe\xff\xff\xea"-"\xf0\xff\xff\xff"-"\xfc\xff\xff\xff"-"warn"-"\xff\xff\xff\xff"-"\xfe\xff\xff\xfb"-"\x00\x00\x00\x80"-"\xfe\xff\xff\xf1"-"\xfe\xff\xff\xea"-"\x00\x00\x00\x00\x00\x00\x012"-"\xe2\x00"-"\xfb\xff\xff\xff"-"\x00\x00\x00\x00"-"\xe9\xff\xff\xff"-"\xff\xff"-"\x00\x00\x00\x80"-"\x01\x00\x04\xc9"-"\xf0\xff\xff\xff"-"\xf9\xff\xff\xff"-"\xff\xff\xff\xff\xff\xff\xff\x12"-"\xe2\x00"-"\xfe\xff\xff\xff"-"\xfe\xff\xff\xea"-"\xff\xff\xff\xff"-"\xf4\xff\xff\xff"-"\xe9\xff\xff\xff"-"\xf1\xff\xff\xff"-
#48 NEW cov: 4502 ft: 9151 corp: 27/750Kb lim: 64000 exec/s: 2 rss: 458Mb L: 50772/50772 MS: 259 ChangeByte-ShuffleBytes-ChangeBinInt-ChangeByte-ChangeByte-ChangeByte-ChangeByte-ChangeBit-CopyPart-CrossOver-CopyPart-ChangeByte-CrossOver-CopyPart-ChangeBit-ChangeByte-EraseBytes-ChangeByte-CopyPart-CopyPart-CopyPart-ChangeBit-EraseBytes-ChangeBinInt-CrossOver-CopyPart-CrossOver-CopyPart-ChangeBit-ChangeByte-ChangeBit-InsertByte-CrossOver-InsertRepeatedBytes-InsertRepeatedBytes-InsertRepeatedBytes-ChangeBinInt-EraseBytes-InsertRepeatedBytes-InsertByte-ChangeBit-ShuffleBytes-ChangeBit-ChangeBit-CopyPart-ChangeBit-ChangeByte-CrossOver-ChangeBinInt-ChangeByte-CrossOver-CMP-ChangeByte-CrossOver-ChangeByte-ShuffleBytes-ShuffleBytes-ChangeByte-ChangeBinInt-CopyPart-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-InsertByte-ChangeBit-CopyPart-ChangeBinInt-ChangeByte-CrossOver-ChangeBit-EraseBytes-CopyPart-ChangeBinInt-ChangeBit-ChangeBit-ChangeByte-CopyPart-ChangeBinInt-CrossOver-PersAutoDict-ChangeByte-ChangeBit-ChangeByte-ChangeBinInt-ChangeBinInt-EraseBytes-CopyPart-CopyPart-ChangeByte-ChangeByte-EraseBytes-PersAutoDict-CopyPart-ChangeByte-ChangeByte-EraseBytes-CrossOver-CopyPart-CopyPart-CopyPart-ChangeByte-ChangeBit-CMP-CopyPart-ChangeBinInt-ChangeBinInt-CrossOver-ChangeBit-ChangeBit-EraseBytes-ChangeByte-ShuffleBytes-ChangeBit-ChangeBinInt-CMP-InsertRepeatedBytes-CopyPart-Custom-ChangeByte-CrossOver-EraseBytes-ChangeBit-CopyPart-CrossOver-CMP-ShuffleBytes-EraseBytes-CrossOver-PersAutoDict-ChangeByte-CrossOver-CopyPart-CrossOver-CrossOver-ShuffleBytes-ChangeBinInt-CrossOver-ChangeBinInt-ShuffleBytes-PersAutoDict-ChangeByte-EraseBytes-ChangeBit-CrossOver-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-EraseBytes-InsertByte-InsertRepeatedBytes-InsertByte-InsertByte-ChangeByte-ChangeBinInt-ChangeBit-CrossOver-ChangeByte-CrossOver-EraseBytes-ChangeByte-ShuffleBytes-ChangeBit-ChangeBit-ShuffleBytes-CopyPart-ChangeByte-PersAutoDict-ChangeBit-ChangeByte-InsertRepeatedBytes-CMP-CrossOver-ChangeByte-EraseBytes-ShuffleBytes-CrossOver-ShuffleBytes-ChangeBinInt-ChangeBinInt-CopyPart-PersAutoDict-ShuffleBytes-ChangeBit-CopyPart-ShuffleBytes-CopyPart-EraseBytes-ChangeByte-ChangeBit-ChangeBit-ChangeBinInt-ChangeByte-CopyPart-EraseBytes-ChangeBinInt-EraseBytes-EraseBytes-PersAutoDict-CMP-PersAutoDict-CrossOver-CrossOver-ChangeBit-CrossOver-PersAutoDict-CrossOver-CopyPart-ChangeByte-EraseBytes-ChangeByte-ShuffleBytes-ChangeByte-ChangeByte-CrossOver-ChangeBit-EraseBytes-ChangeByte-EraseBytes-ChangeBinInt-CrossOver-CrossOver-EraseBytes-ChangeBinInt-CrossOver-ChangeBit-ShuffleBytes-ChangeBit-ChangeByte-EraseBytes-ChangeBit-CrossOver-CrossOver-CrossOver-ChangeByte-ChangeBit-ShuffleBytes-ChangeBit-ChangeBit-EraseBytes-CrossOver-CrossOver-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-CopyPart-CrossOver-CopyPart-CrossOver-CrossOver-EraseBytes-EraseBytes-ShuffleBytes-InsertRepeatedBytes-ChangeBit-CopyPart-Custom- DE: "\xfe\xff\xff\xfc"-"\x00\x00\x00\x00"-"F\x00"-"\xf3\xff\xff\xff"-"St9exception"-"_\x00\x00\x00"-"\xf6\xff\xff\xff"-"\xfe\xff\xff\xff"-"\x00\x00\x00\x00"-"p\x02\x00\x00\x00\x00\x00\x00"-"\xfe\xff\xff\xfb"-"\xff\xff"-"\xff\xff\xff\xff"-"\x01\x00\x00\x07"-"\xfe\xff\xff\xfe"-

These are prohibitively large and of limited value in the default case (when
someone is running the fuzzer, not debugging it), in my opinion.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D86658

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[libFuzzer] Add a command-line option for tracing mutation of corpus inputs in the dot graph format.

This patch adds a new command-line option -mutation_graph_file=FILE for
debugging purposes, which

[libFuzzer] Add a command-line option for tracing mutation of corpus inputs in the dot graph format.

This patch adds a new command-line option -mutation_graph_file=FILE for
debugging purposes, which traces how corpus inputs evolve during a fuzzing
run. For each new input that is added to the corpus, a new vertex corresponding
to the added input, as well as a new edge that connects its base input to itself
are written to the given file. Each vertex is labeled with the filename of the
input, and each edge is labeled with the mutation sequence that led to the input
w.r.t. its base input.

The format of the mutation graph file is the dot file format. Once prepended and
appended with "graph {" and "}", respectively, the graph becomes a valid dot
file and can be visualized.

Differential Revision: https://reviews.llvm.org/D86560

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[libFuzzer] Scale energy assigned to each input based on input execution time.

This patch scales the energy computed by the Entropic schedule based on the
execution time of each input. The input exe

[libFuzzer] Scale energy assigned to each input based on input execution time.

This patch scales the energy computed by the Entropic schedule based on the
execution time of each input. The input execution time is compared with the
average execution time of inputs in the corpus, and, based on the amount by
which they differ, the energy is scaled from 0.1x (for inputs executing slow) to
3x (for inputs executing fast). Note that the exact scaling criteria and formula
is borrowed from AFL.

On FuzzBench, this gives a sizeable throughput increase, which in turn leads to
more coverage on several benchmarks. For details, see the following report.

https://storage.googleapis.com/fuzzer-test-suite-public/exectime-report/index.html

Differential Revision: https://reviews.llvm.org/D86092

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[libFuzzer] Evenly select inputs to cross over with from the corpus regardless of the input's coverage.

This patch adds an option "cross_over_uniform_dist", which, if 1, considers all
inputs in the

[libFuzzer] Evenly select inputs to cross over with from the corpus regardless of the input's coverage.

This patch adds an option "cross_over_uniform_dist", which, if 1, considers all
inputs in the corpus for the crossover input selection. More specifically, this
patch uses a uniform distribution of all inputs in the corpus for the CrossOver
input selection. Note that input selection for mutation is still fully
determined by the scheduling policy (i.e., vanilla or Entropic); the uniform
distribution only applies to the secondary input selection, only for the
crossover mutation of the base input chosen by the scheduling policy. This way
the corpus inputs that have useful fragments in them, even though they are
deprioritized by the scheduling policy, have chances of getting mixed with other
inputs that are prioritized and selected as base input for mutation.

Differential Revision: https://reviews.llvm.org/D86954

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[libFuzzer] Add an option to keep initial seed inputs around.

This patch adds an option "keep_seed" to keep all initial seed inputs in the
corpus. Previously, only the initial seed inputs that find

[libFuzzer] Add an option to keep initial seed inputs around.

This patch adds an option "keep_seed" to keep all initial seed inputs in the
corpus. Previously, only the initial seed inputs that find new coverage were
added to the corpus, and all the other initial inputs were discarded. We
observed in some circumstances that useful initial seed inputs are discarded as
they find no new coverage, even though they contain useful fragments in them
(e.g., SQLITE3 FuzzBench benchmark). This newly added option provides a way to
keeping seed inputs in the corpus for those circumstances. With this patch, and
with -keep_seed=1, all initial seed inputs are kept in the corpus regardless of
whether they find new coverage or not. Further, these seed inputs are not
replaced with smaller inputs even if -reduce_inputs=1.

Differential Revision: https://reviews.llvm.org/D86577

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Revert "[libfuzzer] Reduce default verbosity when printing large mutation sequences"

This reverts commit 2665425908e00618074e42155ec922a37f7c9002 due to
buildbot failure.

[libfuzzer] Reduce default verbosity when printing large mutation sequences

When using a custom mutator (e.g. thrift mutator, similar to LPM)
that calls back into libfuzzer's mutations via `LLVMFuzz

[libfuzzer] Reduce default verbosity when printing large mutation sequences

When using a custom mutator (e.g. thrift mutator, similar to LPM)
that calls back into libfuzzer's mutations via `LLVMFuzzerMutate`, the mutation
sequences needed to achieve new coverage can get prohibitively large.

Printing these large sequences has two downsides:

1) It makes the logs hard to understand for a human.
2) The performance cost slows down fuzzing.

In this patch I change the `PrintMutationSequence` function to take a max
number of entries, to achieve this goal. I also update `PrintStatusForNewUnit`
to default to printing only 10 entries, in the default verbosity level (1),
requiring the user to set verbosity to 2 if they want the full mutation
sequence.

For our use case, turning off verbosity is not an option, as that would also
disable `PrintStats()` which is very useful for infrastructure that analyzes
the logs in realtime. I imagine most users of libfuzzer always want those logs
in the default.

I built a fuzzer locally with this patch applied to libfuzzer.

When running with the default verbosity, I see logs like this:

#65 NEW cov: 4799 ft: 10443 corp: 41/1447Kb lim: 64000 exec/s: 1 rss: 575Mb L: 28658/62542 MS: 196 Custom-CrossOver-ChangeBit-EraseBytes-ChangeBit-ChangeBit-ChangeBit-CrossOver-ChangeBit-CrossOver- DE: "\xff\xff\xff\x0e"-"\xfe\xff\xff\x7f"-"\xfe\xff\xff\x7f"-"\x17\x00\x00\x00\x00\x00\x00\x00"-"\x00\x00\x00\xf9"-"\xff\xff\xff\xff"-"\xfa\xff\xff\xff"-"\xf7\xff\xff\xff"-"@\xff\xff\xff\xff\xff\xff\xff"-"E\x00"-
#67 NEW cov: 4810 ft: 10462 corp: 42/1486Kb lim: 64000 exec/s: 1 rss: 577Mb L: 39823/62542 MS: 135 Custom-CopyPart-ShuffleBytes-ShuffleBytes-ChangeBit-ChangeBinInt-EraseBytes-ChangeBit-ChangeBinInt-ChangeBit- DE: "\x01\x00\x00\x00\x00\x00\x01\xf1"-"\x00\x00\x00\x07"-"\x00\x0d"-"\xfd\xff\xff\xff"-"\xfe\xff\xff\xf4"-"\xe3\xff\xff\xff"-"\xff\xff\xff\xf1"-"\xea\xff\xff\xff"-"\x00\x00\x00\xfd"-"\x01\x00\x00\x05"-

Staring hard at the logs it's clear that the cap of 10 is applied.

When running with verbosity level 2, the logs look like the below:

#66 NEW cov: 4700 ft: 10188 corp: 37/1186Kb lim: 64000 exec/s: 2 rss: 509Mb L: 47616/61231 MS: 520 Custom-CopyPart-ChangeBinInt-ChangeBit-ChangeByte-EraseBytes-PersAutoDict-CopyPart-ShuffleBytes-ChangeBit-ShuffleBytes-CopyPart-EraseBytes-CopyPart-ChangeBinInt-CopyPart-ChangeByte-ShuffleBytes-ChangeBinInt-ShuffleBytes-ChangeBit-CMP-ShuffleBytes-ChangeBit-CrossOver-ChangeBinInt-ChangeByte-ShuffleBytes-CrossOver-EraseBytes-ChangeBinInt-InsertRepeatedBytes-PersAutoDict-InsertRepeatedBytes-InsertRepeatedBytes-CrossOver-ChangeByte-ShuffleBytes-CopyPart-ShuffleBytes-CopyPart-CrossOver-ChangeBit-ShuffleBytes-CrossOver-PersAutoDict-ChangeByte-ChangeBit-ShuffleBytes-CrossOver-ChangeByte-EraseBytes-CopyPart-ChangeBinInt-PersAutoDict-CrossOver-ShuffleBytes-CrossOver-CrossOver-EraseBytes-CrossOver-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-ChangeByte-EraseBytes-ShuffleBytes-ShuffleBytes-ChangeBit-EraseBytes-ChangeBinInt-ChangeBit-ChangeBinInt-CopyPart-EraseBytes-PersAutoDict-EraseBytes-CopyPart-ChangeBinInt-ChangeByte-CrossOver-ChangeBinInt-ShuffleBytes-PersAutoDict-PersAutoDict-ChangeBinInt-CopyPart-ChangeBinInt-CrossOver-ChangeBit-ChangeBinInt-CopyPart-ChangeByte-ChangeBit-CopyPart-CrossOver-ChangeByte-ChangeBit-ChangeByte-ShuffleBytes-CMP-ChangeBit-CopyPart-ChangeBit-ChangeByte-ChangeBinInt-PersAutoDict-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBit-ChangeBinInt-ChangeBinInt-PersAutoDict-ChangeBinInt-ChangeBinInt-ChangeByte-CopyPart-ShuffleBytes-ChangeByte-ChangeBit-ChangeByte-ChangeByte-EraseBytes-CrossOver-ChangeByte-ChangeByte-EraseBytes-EraseBytes-InsertRepeatedBytes-ShuffleBytes-CopyPart-CopyPart-ChangeBit-ShuffleBytes-PersAutoDict-ShuffleBytes-ChangeBit-ChangeByte-ChangeBit-ShuffleBytes-ChangeByte-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBit-EraseBytes-CopyPart-ChangeByte-CrossOver-EraseBytes-CrossOver-ChangeByte-ShuffleBytes-ChangeByte-ChangeBinInt-CrossOver-ChangeByte-InsertRepeatedBytes-InsertByte-ShuffleBytes-PersAutoDict-ChangeBit-ChangeByte-ChangeBit-ShuffleBytes-ShuffleBytes-CopyPart-ShuffleBytes-EraseBytes-ShuffleBytes-ShuffleBytes-CrossOver-ChangeBinInt-CopyPart-CopyPart-CopyPart-EraseBytes-EraseBytes-ChangeByte-ChangeBinInt-ShuffleBytes-CMP-InsertByte-EraseBytes-ShuffleBytes-CopyPart-ChangeBit-CrossOver-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-EraseBytes-ChangeByte-ChangeBinInt-ChangeBit-ChangeBit-ChangeByte-ShuffleBytes-PersAutoDict-PersAutoDict-CMP-ChangeBit-ShuffleBytes-PersAutoDict-ChangeBinInt-EraseBytes-EraseBytes-ShuffleBytes-ChangeByte-ShuffleBytes-ChangeBit-EraseBytes-CMP-ShuffleBytes-ChangeByte-ChangeBinInt-EraseBytes-ChangeBinInt-ChangeByte-EraseBytes-ChangeByte-CrossOver-ShuffleBytes-EraseBytes-EraseBytes-ShuffleBytes-ChangeBit-EraseBytes-CopyPart-ShuffleBytes-ShuffleBytes-CrossOver-CopyPart-ChangeBinInt-ShuffleBytes-CrossOver-InsertByte-InsertByte-ChangeBinInt-ChangeBinInt-CopyPart-EraseBytes-ShuffleBytes-ChangeBit-ChangeBit-EraseBytes-ChangeByte-ChangeByte-ChangeBinInt-CrossOver-ChangeBinInt-ChangeBinInt-ShuffleBytes-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-ShuffleBytes-CrossOver-EraseBytes-CopyPart-CopyPart-CopyPart-ChangeBit-ShuffleBytes-ChangeByte-EraseBytes-ChangeByte-InsertRepeatedBytes-InsertByte-InsertRepeatedBytes-PersAutoDict-EraseBytes-ShuffleBytes-ChangeByte-ShuffleBytes-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeBit-CrossOver-CrossOver-ShuffleBytes-CrossOver-CopyPart-CrossOver-CrossOver-CopyPart-ChangeByte-ChangeByte-CrossOver-ChangeBit-ChangeBinInt-EraseBytes-ShuffleBytes-EraseBytes-CMP-PersAutoDict-PersAutoDict-InsertByte-ChangeBit-ChangeByte-CopyPart-CrossOver-ChangeByte-ChangeBit-ChangeByte-CopyPart-ChangeBinInt-EraseBytes-CrossOver-ChangeBit-CrossOver-PersAutoDict-CrossOver-ChangeByte-CrossOver-ChangeByte-ChangeByte-CrossOver-ShuffleBytes-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-ChangeBinInt-ChangeBinInt-ChangeBinInt-ChangeBinInt-ShuffleBytes-CrossOver-ChangeBinInt-ShuffleBytes-ChangeBit-PersAutoDict-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeByte-CrossOver-ChangeBit-CopyPart-ChangeBit-ChangeBit-CopyPart-ChangeByte-PersAutoDict-ChangeBit-ShuffleBytes-ChangeByte-ChangeBit-CrossOver-ChangeByte-CrossOver-ChangeByte-CrossOver-ChangeBit-ChangeByte-ChangeBinInt-PersAutoDict-CopyPart-ChangeBinInt-ChangeBit-CrossOver-ChangeBit-PersAutoDict-ShuffleBytes-EraseBytes-CrossOver-ChangeByte-ChangeBinInt-ShuffleBytes-ChangeBinInt-InsertRepeatedBytes-PersAutoDict-CrossOver-ChangeByte-Custom-PersAutoDict-CopyPart-CopyPart-ChangeBinInt-ShuffleBytes-ChangeBinInt-ChangeBit-ShuffleBytes-CrossOver-CMP-ChangeByte-CopyPart-ShuffleBytes-CopyPart-CopyPart-CrossOver-CrossOver-CrossOver-ShuffleBytes-ChangeByte-ChangeBinInt-ChangeBit-ChangeBit-ChangeBit-ChangeByte-EraseBytes-ChangeByte-ChangeBit-ChangeByte-ChangeByte-CopyPart-PersAutoDict-ChangeBinInt-PersAutoDict-PersAutoDict-PersAutoDict-CopyPart-CopyPart-CrossOver-ChangeByte-ChangeBinInt-ShuffleBytes-ChangeBit-CopyPart-EraseBytes-CopyPart-CopyPart-CrossOver-ChangeByte-EraseBytes-ShuffleBytes-ChangeByte-CopyPart-EraseBytes-CopyPart-CrossOver-ChangeBinInt-ChangeBinInt-InsertByte-ChangeBinInt-ChangeBit-ChangeByte-CopyPart-ChangeByte-EraseBytes-ChangeByte-ChangeBit-ChangeByte-ShuffleBytes-CopyPart-ChangeBinInt-EraseBytes-CrossOver-ChangeBit-ChangeBit-CrossOver-EraseBytes-ChangeBinInt-CopyPart-CopyPart-ChangeBinInt-ChangeBit-EraseBytes-InsertRepeatedBytes-EraseBytes-ChangeBit-CrossOver-CrossOver-EraseBytes-EraseBytes-ChangeByte-CopyPart-CopyPart-ShuffleBytes-ChangeByte-ChangeBit-ChangeByte-EraseBytes-ChangeBit-ChangeByte-ChangeByte-CrossOver-CopyPart-EraseBytes-ChangeByte-EraseBytes-ChangeByte-ShuffleBytes-ShuffleBytes-ChangeByte-CopyPart-ChangeByte-ChangeByte-ChangeBit-CopyPart-ChangeBit-ChangeBinInt-CopyPart-ShuffleBytes-ChangeBit-ChangeBinInt-ChangeBit-EraseBytes-CMP-CrossOver-CopyPart-ChangeBinInt-CrossOver-CrossOver-CopyPart-CrossOver-CrossOver-InsertByte-InsertByte-CopyPart-Custom- DE: "warn"-"\x00\x00\x00\x80"-"\xfe\xff\xff\xfb"-"\xff\xff"-"\x10\x00\x00\x00"-"\xfe\xff\xff\xff"-"\xff\xff\xff\xf6"-"U\x01\x00\x00\x00\x00\x00\x00"-"\xd9\xff\xff\xff"-"\xfe\xff\xff\xea"-"\xf0\xff\xff\xff"-"\xfc\xff\xff\xff"-"warn"-"\xff\xff\xff\xff"-"\xfe\xff\xff\xfb"-"\x00\x00\x00\x80"-"\xfe\xff\xff\xf1"-"\xfe\xff\xff\xea"-"\x00\x00\x00\x00\x00\x00\x012"-"\xe2\x00"-"\xfb\xff\xff\xff"-"\x00\x00\x00\x00"-"\xe9\xff\xff\xff"-"\xff\xff"-"\x00\x00\x00\x80"-"\x01\x00\x04\xc9"-"\xf0\xff\xff\xff"-"\xf9\xff\xff\xff"-"\xff\xff\xff\xff\xff\xff\xff\x12"-"\xe2\x00"-"\xfe\xff\xff\xff"-"\xfe\xff\xff\xea"-"\xff\xff\xff\xff"-"\xf4\xff\xff\xff"-"\xe9\xff\xff\xff"-"\xf1\xff\xff\xff"-
#48 NEW cov: 4502 ft: 9151 corp: 27/750Kb lim: 64000 exec/s: 2 rss: 458Mb L: 50772/50772 MS: 259 ChangeByte-ShuffleBytes-ChangeBinInt-ChangeByte-ChangeByte-ChangeByte-ChangeByte-ChangeBit-CopyPart-CrossOver-CopyPart-ChangeByte-CrossOver-CopyPart-ChangeBit-ChangeByte-EraseBytes-ChangeByte-CopyPart-CopyPart-CopyPart-ChangeBit-EraseBytes-ChangeBinInt-CrossOver-CopyPart-CrossOver-CopyPart-ChangeBit-ChangeByte-ChangeBit-InsertByte-CrossOver-InsertRepeatedBytes-InsertRepeatedBytes-InsertRepeatedBytes-ChangeBinInt-EraseBytes-InsertRepeatedBytes-InsertByte-ChangeBit-ShuffleBytes-ChangeBit-ChangeBit-CopyPart-ChangeBit-ChangeByte-CrossOver-ChangeBinInt-ChangeByte-CrossOver-CMP-ChangeByte-CrossOver-ChangeByte-ShuffleBytes-ShuffleBytes-ChangeByte-ChangeBinInt-CopyPart-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-InsertByte-ChangeBit-CopyPart-ChangeBinInt-ChangeByte-CrossOver-ChangeBit-EraseBytes-CopyPart-ChangeBinInt-ChangeBit-ChangeBit-ChangeByte-CopyPart-ChangeBinInt-CrossOver-PersAutoDict-ChangeByte-ChangeBit-ChangeByte-ChangeBinInt-ChangeBinInt-EraseBytes-CopyPart-CopyPart-ChangeByte-ChangeByte-EraseBytes-PersAutoDict-CopyPart-ChangeByte-ChangeByte-EraseBytes-CrossOver-CopyPart-CopyPart-CopyPart-ChangeByte-ChangeBit-CMP-CopyPart-ChangeBinInt-ChangeBinInt-CrossOver-ChangeBit-ChangeBit-EraseBytes-ChangeByte-ShuffleBytes-ChangeBit-ChangeBinInt-CMP-InsertRepeatedBytes-CopyPart-Custom-ChangeByte-CrossOver-EraseBytes-ChangeBit-CopyPart-CrossOver-CMP-ShuffleBytes-EraseBytes-CrossOver-PersAutoDict-ChangeByte-CrossOver-CopyPart-CrossOver-CrossOver-ShuffleBytes-ChangeBinInt-CrossOver-ChangeBinInt-ShuffleBytes-PersAutoDict-ChangeByte-EraseBytes-ChangeBit-CrossOver-EraseBytes-CrossOver-ChangeBit-ChangeBinInt-EraseBytes-InsertByte-InsertRepeatedBytes-InsertByte-InsertByte-ChangeByte-ChangeBinInt-ChangeBit-CrossOver-ChangeByte-CrossOver-EraseBytes-ChangeByte-ShuffleBytes-ChangeBit-ChangeBit-ShuffleBytes-CopyPart-ChangeByte-PersAutoDict-ChangeBit-ChangeByte-InsertRepeatedBytes-CMP-CrossOver-ChangeByte-EraseBytes-ShuffleBytes-CrossOver-ShuffleBytes-ChangeBinInt-ChangeBinInt-CopyPart-PersAutoDict-ShuffleBytes-ChangeBit-CopyPart-ShuffleBytes-CopyPart-EraseBytes-ChangeByte-ChangeBit-ChangeBit-ChangeBinInt-ChangeByte-CopyPart-EraseBytes-ChangeBinInt-EraseBytes-EraseBytes-PersAutoDict-CMP-PersAutoDict-CrossOver-CrossOver-ChangeBit-CrossOver-PersAutoDict-CrossOver-CopyPart-ChangeByte-EraseBytes-ChangeByte-ShuffleBytes-ChangeByte-ChangeByte-CrossOver-ChangeBit-EraseBytes-ChangeByte-EraseBytes-ChangeBinInt-CrossOver-CrossOver-EraseBytes-ChangeBinInt-CrossOver-ChangeBit-ShuffleBytes-ChangeBit-ChangeByte-EraseBytes-ChangeBit-CrossOver-CrossOver-CrossOver-ChangeByte-ChangeBit-ShuffleBytes-ChangeBit-ChangeBit-EraseBytes-CrossOver-CrossOver-CopyPart-ShuffleBytes-ChangeByte-ChangeByte-CopyPart-CrossOver-CopyPart-CrossOver-CrossOver-EraseBytes-EraseBytes-ShuffleBytes-InsertRepeatedBytes-ChangeBit-CopyPart-Custom- DE: "\xfe\xff\xff\xfc"-"\x00\x00\x00\x00"-"F\x00"-"\xf3\xff\xff\xff"-"St9exception"-"_\x00\x00\x00"-"\xf6\xff\xff\xff"-"\xfe\xff\xff\xff"-"\x00\x00\x00\x00"-"p\x02\x00\x00\x00\x00\x00\x00"-"\xfe\xff\xff\xfb"-"\xff\xff"-"\xff\xff\xff\xff"-"\x01\x00\x00\x07"-"\xfe\xff\xff\xfe"-

These are prohibitively large and of limited value in the default case (when
someone is running the fuzzer, not debugging it), in my opinion.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D86658

show more ...

[libFuzzer] Fix compilation error by including missing platform macro definitions.

Summary: This patch fixes sanitizer-windows build errors.

Reviewers: morehouse, hctim

Reviewed By: morehouse, hct

[libFuzzer] Fix compilation error by including missing platform macro definitions.

Summary: This patch fixes sanitizer-windows build errors.

Reviewers: morehouse, hctim

Reviewed By: morehouse, hctim

Subscribers: #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D83823

show more ...

Entropic: Boosting LibFuzzer Performance

Summary:
This is collaboration between Marcel Boehme @ Monash, Australia and Valentin Manès plus Sang Kil Cha @ KAIST, South Korea.

We have made a few modif

Entropic: Boosting LibFuzzer Performance

Summary:
This is collaboration between Marcel Boehme @ Monash, Australia and Valentin Manès plus Sang Kil Cha @ KAIST, South Korea.

We have made a few modifications to boost LibFuzzer performance by changing how weights are assigned to the seeds in the corpus. Essentially, seeds that reveal more "information" about globally rare features are assigned a higher weight. Our results on the Fuzzer Test Suite seem quite promising. In terms of bug finding, our Entropic patch usually finds the same errors much faster and in more runs. In terms of coverage, our version Entropic achieves the same coverage in less than half the time for the majority of subjects. For the lack of space, we shared more detailed performance results directly with @kcc. We'll publish the preprint with all the technical details as soon as it is accepted. Happy to share if you drop us an email.

There should be plenty of opportunities to optimise further. For instance, while Entropic achieves the same coverage in less than half the time, Entropic has a much lower #execs per second. We ran the perf-tool and found a few performance bottlenecks.

Thanks for open-sourcing LibFuzzer (and the entire LLVM Compiler Infrastructure)! This has been such a tremendous help to my research.

Patch By: Marcel Boehme

Reviewers: kcc, metzman, morehouse, Dor1s, vitalybuka

Reviewed By: kcc

Subscribers: dgg5503, Valentin, llvm-commits, kcc

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73776

show more ...

[libFuzzer] Fix denominator in the "inputs have DFT" log line.

Summary:
The number of "inputs have the Data Flow Trace" cannot be greater than
the number of inputs touching the focus function. The e

[libFuzzer] Fix denominator in the "inputs have DFT" log line.

Summary:
The number of "inputs have the Data Flow Trace" cannot be greater than
the number of inputs touching the focus function. The existing message is rather
confusing as the same log would mention a greater total number of traces a few
lines above.

Reviewers: kcc, metzman

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74779

show more ...

Reland "[NFC][libFuzzer] Prefix TempPath with string showing the work it is doing."

With fix (somehow one hunk is missed).

Revert "[NFC][libFuzzer] Prefix TempPath with string showing the work it is doing."

This reverts commit 8a29cb4421f1196bc40c4db5298ca13df516bf19.

fuzzer-linux bot has failure because of this.

[NFC][libFuzzer] Prefix TempPath with string showing the work it is doing.