Commit Graph

9 Commits

Author SHA1 Message Date
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
Dan Liew
25d0c65ff3 [LibFuzzer] Try to unbreak the FuzzerMutate.ShuffleBytes1 unit test.
This test is failing on my Linux box. Just increasing the number of
iterations works around this. The divergence is likely due to
our reliance on `std::shuffle()` which is not guaranteed to have
the same behaviour across platforms.

This is a strong argument for us to implement our own shuffle
function to avoid divergence in behaviour across platforms.

Differential Revision: https://reviews.llvm.org/D45767

llvm-svn: 330390
2018-04-20 06:46:14 +00:00
Kostya Serebryany
a97bd9a7d3 [libFuzzer] Decrease stack usage in unit tests
Summary: With 3 Dictionary objects, each containing space of ~16k DictionaryEntry objects, the MutationDispatcher object is fairly memory heavy.  On platforms with a lower default stack size, this can cause panics in FuzzerUnittest as those tests stack-allocate the MutationDispatcher.  This may be especially problematic for platforms that do not (yet) have a way to programmatically change their stack size, aside from link-time flags.  In general, it seems more prudent to use the heap for an object of this size.

Reviewers: kcc, morehouse

Reviewed By: kcc

Differential Revision: https://reviews.llvm.org/D40926

llvm-svn: 319988
2017-12-06 23:35:02 +00:00
Matt Morehouse
056774d13b [libFuzzer] Make redirects happen in proper sequence.
"> file" must come before "2>&1" to have redirection occur correctly in
all cases.  Fixes a regression on minimize_two_crashes.test.

llvm-svn: 319792
2017-12-05 17:13:17 +00:00
Matt Morehouse
04304d129b [libFuzzer] Encapsulate commands in a class.
Summary:
To be more portable (especially w.r.t. platforms without system()),
commands should be managed programmatically rather than via string
manipulation on the command line. This change introduces
Fuzzer::Command, with methods to manage arguments and flags, set output
options, and execute the command.

Patch By: aarongreen

Reviewers: kcc, morehouse

Reviewed By: kcc, morehouse

Subscribers: llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D40103

llvm-svn: 319680
2017-12-04 19:25:59 +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