Commit Graph

87 Commits

Author SHA1 Message Date
Max Moroz 8db0befc6d [libFuzzer] Handle unstable edges by disregarding unstable edges
Summary:
Added a new mode within flag -handle_unstable for new unstable handling algorithm that does the following:
    When an edge is shown as unstable, copy to UnstableCounters the value 0.
    During ApplyUnstableCounters we copy back the value 0 to ModuleInline8bitCounters if the edge was unstable.

This way we would be ignoring completely features that were collected through non-determinism.
Unstable hits would be counted as if it never hit.

Reviewers: metzman, Dor1s, kcc, morehouse

Reviewed By: metzman, morehouse

Subscribers: delcypher, llvm-commits, #sanitizers

Differential Revision: https://reviews.llvm.org/D49684

llvm-svn: 337853
2018-07-24 21:02:44 +00:00
Max Moroz 1e954f78d1 [libFuzzer] Handle unstable edges by using minimum hit counts
Summary:
Created unstable_handle flag that takes 1 or 2, depending on the handling type.
Modified RunOne to accommodate the following heuristic:
    Use the first CollectFeatures to count how many features there are.
    If no new features, CollectFeatures like before.
    If there is new feature, we run CB 2 more times,
        Check which edges are unstable per input and we store the least amount of hit counts for each edge.
        Apply these hit counts back to inline8bitcounters so that CollectFeatures can work as intended.
Modified UnstableCounters to 8int_t and created a bitset UnstableSet to tell which edges are unstable.

Patch by Kyungtak Woo (@kevinwkt).

Reviewers: Dor1s, metzman, morehouse

Reviewed By: Dor1s, morehouse

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

Differential Revision: https://reviews.llvm.org/D49525

llvm-svn: 337696
2018-07-23 14:20:52 +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
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
Max Moroz 08dad54924 [libFuzzer] Implement stat::stability_rate based on the percentage of unstable edges.
Summary:
Created a -print_unstable_stats flag.
When -print_unstable_stats=1, we run it 2 more times on interesting inputs poisoning unstable edges in an array.
On program termination, we run PrintUnstableStats() which will print a line with a stability percentage like AFL does.

Patch by Kyungtak Woo (@kevinwkt).

Reviewers: metzman, Dor1s, kcc, morehouse

Reviewed By: metzman, Dor1s, morehouse

Subscribers: delcypher, llvm-commits, #sanitizers, kcc, morehouse, Dor1s

Differential Revision: https://reviews.llvm.org/D49212

llvm-svn: 337187
2018-07-16 16:01:31 +00:00
Max Moroz 1d369a5d01 Revert r337175 (https://reviews.llvm.org/D49212) due to unintentional format changes.
llvm-svn: 337180
2018-07-16 15:15:34 +00:00
Max Moroz 2156d885e0 [libFuzzer] Implement stat::stability_rate based on the percentage of unstable edges.
Summary:
Created a -print_unstable_stats flag.
When -print_unstable_stats=1, we run it 2 more times on interesting inputs poisoning unstable edges in an array.
On program termination, we run PrintUnstableStats() which will print a line with a stability percentage like AFL does.

Patch by Kyungtak Woo (@kevinwkt).

Reviewers: metzman, Dor1s, kcc, morehouse

Reviewed By: metzman, Dor1s, morehouse

Subscribers: delcypher, llvm-commits, #sanitizers, kcc, morehouse, Dor1s

Differential Revision: https://reviews.llvm.org/D49212

llvm-svn: 337175
2018-07-16 14:54:23 +00:00
Matt Morehouse a34c65e845 [libFuzzer] Make -fsanitize=memory,fuzzer work.
This patch allows libFuzzer to fuzz applications instrumented with MSan
without recompiling libFuzzer with MSan instrumentation.

Fixes https://github.com/google/sanitizers/issues/958.

Differential Revision: https://reviews.llvm.org/D48891

llvm-svn: 336619
2018-07-09 23:51:08 +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
Kostya Serebryany 4d9fd7a266 [libFuzzer] remove an experimental flag -use_feature_frequency
llvm-svn: 334146
2018-06-06 23:24:41 +00:00
Kostya Serebryany 1fd005f552 [libFuzzer] initial implementation of -data_flow_trace. It parses the data flow trace and prints the summary, but doesn't use the information in any other way yet
llvm-svn: 334058
2018-06-06 01:23:29 +00:00
Kostya Serebryany 69c2b71a51 [libFuzzer] reinstate -dump_coverage, which is still in use (reverts r332036)
llvm-svn: 332876
2018-05-21 19:47:00 +00:00
Kostya Serebryany e9c6f06cce [libFuzzer] add an experimental flag -focus_function: libFuzzer will try to focus on inputs that trigger that function
llvm-svn: 332554
2018-05-16 23:26:37 +00:00
Kostya Serebryany 2f7edaeb39 [libFuzzer] deprecate equivalence_server
llvm-svn: 332316
2018-05-15 01:15:47 +00:00
Kostya Serebryany d80e821646 [libFuzzer] remove the dump_coverage flag, it hasn't been working with the inline sanitizer coverage anyway
llvm-svn: 332036
2018-05-10 20:24:39 +00:00
Kostya Serebryany 59bf1e8b36 [libFuzzer] remove the experimental support for clang coverage instrumentation. This mode has not been used and our experiments with https://github.com/google/fuzzer-test-suite show that this signal is weaker than the SanitizerCoverage
llvm-svn: 332034
2018-05-10 20:12:15 +00:00
Sylvestre Ledru d9a8b6a745 fix some user facing typos / in the comments
llvm-svn: 327402
2018-03-13 14:35:10 +00:00
Matt Morehouse 36c89b3c77 [libFuzzer] Set -experimental_len_control=1000 as default.
Summary:
Experiments using
https://github.com/google/fuzzer-test-suite/tree/master/engine-comparison
show a significant increase in coverage and reduction in corpus size
with this option enabled.

Addresses https://llvm.org/pr36371.

Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42932

llvm-svn: 325050
2018-02-13 20:52:15 +00:00
Kostya Serebryany 7ac58ee3e1 [libFuzzer] fix a minor regression in printing
llvm-svn: 319975
2017-12-06 22:12:24 +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
Kostya Serebryany de9bafb162 [libFuzzer] add a flag -malloc_limit_mb
llvm-svn: 319590
2017-12-01 22:12:04 +00:00
Kostya Serebryany 6afa7a54be [libFuzzer] remove stale flags; NFC
llvm-svn: 319572
2017-12-01 19:24:06 +00:00
Kostya Serebryany ad05ee0512 [libFuzzer] add an experimental search heuristic flag -reduce_depth
llvm-svn: 319571
2017-12-01 19:18:38 +00:00
Kostya Serebryany a2ca2dcc46 [libFuzzer] handle SIGUSR1/SIGUSR2 and try to exit grafully on these signals
llvm-svn: 317829
2017-11-09 20:30:19 +00:00
Kostya Serebryany 68fdef1f7a [libFuzzer] allow user to specify the merge control file
llvm-svn: 317747
2017-11-09 01:05:29 +00:00
Alex Shlyapnikov 6f1c26f222 [libFuzzer] Periodically purge allocator's quarantine to prolong fuzzing sessions.
Summary:
Fuzzing targets that allocate/deallocate a lot of memory tend to consume
a lot of RSS when ASan quarantine is enabled. Purging quarantine between
iterations and returning memory to OS keeps RSS down and should not
reduce the quarantine effectiveness provided the fuzz target does not
preserve state between iterations (in this case this feature can be turned off).

Based on D39153.

Reviewers: vitalybuka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39155

llvm-svn: 316382
2017-10-23 22:04:30 +00:00
Kostya Serebryany 4083d54675 [libFuzzer] experimental flag to tweak the corpus distribution. Seems to improve the situation dramatically on the png benchmark and make things worse on a number of micro-puzzles. Needs more A/B testing
llvm-svn: 315407
2017-10-11 01:44:26 +00:00
Max Moroz 330496c3fc [libFuzzer] Disable experimental clang coverage support by default.
Summary:
It can be enabled via "-use_clang_coverage=1" flag. Reason for disabling:
libFuzzer resets Clang Counters and makes it impossible to generate coverage
report for a regular fuzz target (i.e. not standalone build).

Reviewers: kcc

Reviewed By: kcc

Subscribers: kcc

Differential Revision: https://reviews.llvm.org/D38604

llvm-svn: 315029
2017-10-05 22:41:03 +00:00
Kostya Serebryany bcd78491ef [libFuzzer] minor refactoring, NFC
llvm-svn: 313406
2017-09-15 22:10:36 +00:00
Kostya Serebryany 3a8e3c8336 [libFuzzer] refactoring: move reading the seed corpus closer to where it's consumed; NFC
llvm-svn: 311972
2017-08-29 02:05:01 +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
Kostya Serebryany 2eef816e6e [libFuzzer] add -print_funcs=1 (on bey default): print newly discovered functions during fuzzing
llvm-svn: 311797
2017-08-25 20:09:25 +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