Commit Graph

16 Commits

Author SHA1 Message Date
Max Moroz 8c95b48ba2 [libFuzzer] Remove mutation stats and weighted mutation selection.
Summary:
This was an experimental feature. After evaluating it with:

1) https://github.com/google/fuzzer-test-suite/tree/master/engine-comparison

2) enabling on real world fuzz targets running at ClusterFuzz and OSS-Fuzz

The following conclusions were made:

1) With fuzz targets that have reached a code coverage plateau, the feature does
   not improve libFuzzer's ability to discover new coverage and may actually
   negatively impact it.

2) With fuzz targets that have not yet reached a code coverage plateau, the
   feature might speed up new units discovery in some cases, but it is quite
   rare and hard to confirm with a high level on confidence.

Revert of https://reviews.llvm.org/D48054 and https://reviews.llvm.org/D49621.

Reviewers: metzman, morehouse

Reviewed By: metzman, morehouse

Subscribers: delcypher, #sanitizers, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D51455

llvm-svn: 340976
2018-08-29 21:53:15 +00:00
Max Moroz 5a9baa330c [libFuzzer] Initial implementation of weighted mutation leveraging during runtime.
Summary:
Added functions that calculate stats while fuzz targets are running and give
mutations weight based on how much new coverage they provide, and choose better
performing mutations more often.

Patch by Kodé Williams (@kodewilliams).

Reviewers: Dor1s, metzman, morehouse

Reviewed By: Dor1s, morehouse

Subscribers: delcypher, kcc, llvm-commits, #sanitizers

Differential Revision: https://reviews.llvm.org/D49621

llvm-svn: 338776
2018-08-02 22:30:03 +00:00
Kostya Serebryany 7a6295f2e1 [libFuzzer] fix the bot (the no-assert build)
llvm-svn: 337437
2018-07-19 03:16:12 +00:00
Kostya Serebryany 6b87e0c18f [libFuzzer] first experimental attempt at DFT-based mutations (DFT=data-flow-trace)
llvm-svn: 337434
2018-07-19 01:23:32 +00:00
Max Moroz 061b4af998 [libFuzzer] Mutation tracking and logging implemented.
Summary:
Code now exists to track number of mutations that are used in fuzzing in total
and ones that produce new coverage. The stats are currently being dumped to the
command line.

Patch by Kodé Williams (@kodewilliams).

Reviewers: metzman, Dor1s, morehouse, kcc

Reviewed By: Dor1s, morehouse, kcc

Subscribers: delcypher, kubamracek, kcc, morehouse, llvm-commits, #sanitizers, mgorny

Differential Revision: https://reviews.llvm.org/D48054

llvm-svn: 337324
2018-07-17 20:37:40 +00:00
Matt Morehouse 43a2296976 libFuzzer: prevent irrelevant strings from leaking into auto-dictionary
This is a fix for bug 37047.

https://bugs.llvm.org/show_bug.cgi?id=37047

Implemented by basically reversing the logic. Previously all strings
were considered, with some operations excluded. Now strings are excluded
by default, and only strings during the CB considered.

Patch By: pdknsk

Differential Revision: https://reviews.llvm.org/D48800

llvm-svn: 337296
2018-07-17 16:12:00 +00:00
Max Moroz 5697c59c7f Revert r337194 (https://reviews.llvm.org/D48891) due to compilation errors.
llvm-svn: 337206
2018-07-16 20:05:18 +00:00
Max Moroz 8a5083df53 [libFuzzer] Mutation tracking and logging implemented.
Summary:
Code now exists to track number of mutations that are used in fuzzing in total
and ones that produce new coverage. The stats are currently being dumped to the
command line.

Patch by Kodé Williams (@kodewilliams).

Reviewers: metzman, Dor1s, morehouse, kcc

Reviewed By: Dor1s, morehouse, kcc

Subscribers: delcypher, kubamracek, kcc, morehouse, llvm-commits, #sanitizers, mgorny

Differential Revision: https://reviews.llvm.org/D48054

llvm-svn: 337194
2018-07-16 17:50:46 +00:00
Matt Morehouse a5bb6d53f2 Revert "[libFuzzer] Mutation tracking and logging implemented"
This reverts r336597 due to bot breakage.

llvm-svn: 336616
2018-07-09 22:31:26 +00:00
Matt Morehouse d153d46884 [libFuzzer] Mutation tracking and logging implemented
Code now exists to track number of mutations that are used in fuzzing in
total and ones that produce new coverage. The stats are currently being
dumped to the command line.

Patch By: Kode Williams

Differntial Revision: https://reviews.llvm.org/D48054

llvm-svn: 336597
2018-07-09 20:17:52 +00:00
Dan Liew dfd5a90a99 [LibFuzzer] Tweak `MutationDispatcher::Mutate_CopyPart` mutation.
It doesn't make sense to non-deterministically choose between
`CopyPart(..)` and `InsertPart(..)` when it is known that
`InsertPart(..)` will fail.

This upstream's a change from JFS solver's fork of LibFuzzer.

Differential Revision: https://reviews.llvm.org/D45693

llvm-svn: 330687
2018-04-24 06:31:09 +00:00
Matt Morehouse 1d8e5ea250 [libFuzzer] Fix sizeof(ptr) bug.
sizeof(const char *) returns 4 or 8 when what we really want is the size
of the array.

llvm-svn: 323802
2018-01-30 18:25:55 +00:00
George Karpenkov bebcbfb46d [libFuzzer] Use custom allocators for STL containers in libFuzzer.
Avoids ODR violations causing spurious ASAN warnings.

Differential Revision: https://reviews.llvm.org/D37086

llvm-svn: 311866
2017-08-27 23:20:09 +00:00
George Karpenkov 24069a0424 Revert "[libFuzzer] Use custom allocators for STL containers in libFuzzer"
This reverts commit 3539efc2f2218dba2bcbd645d0fe276f2b5cf588.

llvm-svn: 311831
2017-08-26 17:50:35 +00:00
George Karpenkov d50410bfb1 [libFuzzer] Use custom allocators for STL containers in libFuzzer
Avoids ODR violations causing spurious ASAN container overflow warnings.

Differential Revision: https://reviews.llvm.org/D37086

llvm-svn: 311830
2017-08-26 17:17:37 +00:00
George Karpenkov 10ab2ace13 Move libFuzzer to compiler_rt.
Resulting library binaries will be named libclang_rt.fuzzer*, and will
be placed in Clang toolchain, allowing redistribution.

Differential Revision: https://reviews.llvm.org/D36908

llvm-svn: 311407
2017-08-21 23:25:50 +00:00