Commit Graph

76 Commits

Author SHA1 Message Date
Kostya Serebryany b6ca1e7259 [libFuzzer] make len_control less agressive: set the initial max len to the length of the largest seed. This was the original intent, but... Now, with a test, to ensure it stays this way
llvm-svn: 354191
2019-02-16 01:23:41 +00:00
Kostya Serebryany 312af158b0 [libFuzzer] fork mode: try harder to cleanup after itself
llvm-svn: 354186
2019-02-16 00:14:16 +00:00
Kostya Serebryany 96f81bc679 [libFuzzer] when doing the merge, keep track of the coveraged edges, not just features
llvm-svn: 354076
2019-02-14 23:12:33 +00:00
Kostya Serebryany 63f48717b5 [libFuzzer] extend the -fork=1 functionality. Still not fully usable, but good enough for the first unit test
llvm-svn: 353775
2019-02-12 00:12:33 +00:00
Kostya Serebryany 0fda9dcbe9 [libFuzzer] more refactoring; change some of the exit codes (timeout, OOM, interrupt) so that the parent process can distinguish those
llvm-svn: 353584
2019-02-09 00:16:21 +00:00
Kostya Serebryany f762a11544 [libFuzzer] introduce an experimental mode -fork=1, where fuzzing happens in a subprocess (still running multiple inputs per process), thus making the fuzzing more resilient to timeouts and OOMs. This is just a skeleton of the code, and some associated refactoring, not a fully working feature yet.
llvm-svn: 353570
2019-02-08 21:27:23 +00:00
Kostya Serebryany 0719b3527f [libFuzzer] refactor the way we choose the element to cross-over with, NFC (expected1); add a flag -seed_inputs= to pass extra seed inputs as file paths, not dirs
llvm-svn: 353494
2019-02-08 01:20:54 +00:00
Kostya Serebryany 23482e1d07 [libFuzzer] set libFuzzer's own SEGV handler even one is already present, but call that handler from ours (unless we are unprotecting lazy counters). Call ProtectLazyCounters later, so that it runs after the initialization code in the target.
llvm-svn: 352713
2019-01-31 01:40:14 +00:00
Julian Lettner 15df273eb4 [libFuzzer] Set default sanitizer options in fuzzer tests
Summary:
Set default `ASAN_OPTIONS` when running libFuzzer tests. This allows us
to remove special casing in code for Darwin where we usually pass
`abort_on_error=0` to override platform defaults for tests.

A previous commit changed the code to make the tests pass:
7764a04af0

Adapted a few tests to use `%env_asan_opts=` instead of directly setting
the environment variable.

rdar://problem/47515276

Reviewers: kcc, george.karpenkov

Differential Revision: https://reviews.llvm.org/D57465

llvm-svn: 352711
2019-01-31 01:24:01 +00:00
Kostya Serebryany 8da9479e40 [libFuzzer] experimental performance optimization -lazy_counters, off by default. Posix-only for now, tested on Linux
llvm-svn: 352700
2019-01-31 00:09:43 +00:00
Kostya Serebryany 5c0751ec3e [libFuzzer] remove stale code, NFC
llvm-svn: 352604
2019-01-30 06:21:20 +00:00
Kostya Serebryany 2891b257c2 [libFuzzer] remove stale code
llvm-svn: 352571
2019-01-29 23:53:28 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Jonathan Metzman b795c31dff [libFuzzer][MSVC] Make attribute-use compatible with MSVC
Summary:
Replace attributes with macros that use equivalent declspecs
for MSVC.

Reviewers: vitalybuka

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D56512

llvm-svn: 351456
2019-01-17 16:36:05 +00:00
Jonathan Metzman 9e14cccf6f [libFuzzer] Remove unstable edge handling
Summary:
Remove code for handling unstable edges from libFuzzer since
it has not been found useful.

Differential Revision: https://reviews.llvm.org/D56730

llvm-svn: 351262
2019-01-15 22:12:51 +00:00
Kamil Rytarowski 2e61186c42 Follow Windows' approach for NetBSD in AlarmCallback()
NetBSD's current behavior needs to ignore check for
InFuzzingThread() in Fuzzer::AlarmCallback().

llvm-svn: 346194
2018-11-06 01:28:01 +00:00
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 cd02f3147b [libFuzzer] Optimize handle unstable checks by reducing iterations
Summary:
We only run the 3rd check if 2nd check finds unstable edges. 
3rd UpdateUnstableCounters is now merged with ApplyUnstableCounters to only run 1 iteration.

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/D50411

llvm-svn: 339249
2018-08-08 14:32:46 +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
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
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
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 51ddb88300 [libFuzzer] add one more value profile metric, under a flag (experimental)
llvm-svn: 336234
2018-07-03 22:33:09 +00:00
Kostya Serebryany 67af99235f [libFuzzer] make the corpus elements aware of their data flow traces
llvm-svn: 334158
2018-06-07 01:40:20 +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
Max Moroz fe97441c2c [libFuzzer] Don't complain about lack of interesting inputs when -runs=0.
Summary:
The most common usecase for -runs=0 is for generating code coverage
over some corpus. Coverage reports based on sancov are about to be deprecated,
which means some external coverage solution will be used, e.g. Clang source
based code coverage, which does not use any sancov instrumentations and thus
libFuzzer would consider any input to be not interesting in that case.

Reviewers: kcc

Reviewed By: kcc

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

Differential Revision: https://reviews.llvm.org/D47271

llvm-svn: 333116
2018-05-23 19:42:30 +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 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
Matt Morehouse 14cf71a3a5 [libFuzzer] Guard symbolization with try-lock.
Summary:
When out-of-memory or timeout occurs, threads can be stopped during
symbolization, thereby causing a deadlock when the OOM/TO handlers
attempt symbolization.  We avoid this deadlock by skipping symbolization
if another thread is symbolizing.

Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46605

llvm-svn: 331825
2018-05-08 23:45:05 +00:00
Matt Morehouse 7764a04af0 [libFuzzer] Don't short-circuit from CrashCallback.
Short-circuiting causes tests to fail on Mac since libFuzzer crashes
rather than exiting with an error code when an unexpected signal
happens.

llvm-svn: 331324
2018-05-02 02:55:28 +00:00
Matt Morehouse 52fd169035 [libFuzzer] Report at most one crash per input.
Summary:
Fixes https://github.com/google/sanitizers/issues/788/, a deadlock
caused by multiple crashes happening at the same time.  Before printing
a crash report, we now test and set an atomic flag.  If the flag was
already set, the crash handler returns immediately.

Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits, kubamracek

Differential Revision: https://reviews.llvm.org/D46277

llvm-svn: 331310
2018-05-01 21:01:53 +00:00
Matt Morehouse ddf352b953 [libFuzzer] Include TEMP_MAX_LEN in Fuzzer::PrintStats.
Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43597

llvm-svn: 325817
2018-02-22 19:00:17 +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
Petr Hosek eac2b47b9f Reland "[libFuzzer] Support using libc++"
This is needed in case the users of libFuzzer use libc++ in their
code, which the fuzz target (libFuzzer) will be linked against.
When libc++ source is available, we build a private version of it
and link it against libFuzzer which allows using the same static
library against codebases which use both libc++ and libstdc++.

Differential Revision: https://reviews.llvm.org/D37631

llvm-svn: 322755
2018-01-17 20:39:14 +00:00
Petr Hosek 68bc4bd6e5 Revert "[libFuzzer] Support using libc++"
This reverts commit r322604: test is failing for standalone compiler-rt.

llvm-svn: 322689
2018-01-17 17:24:56 +00:00
Petr Hosek a1b57e694e [libFuzzer] Support using libc++
This is needed in case the users of libFuzzer use libc++ in their
code, which the fuzz target (libFuzzer) will be linked against.
When libc++ source is available, we build a private version of it
and link it against libFuzzer which allows using the same static
library against codebases which use both libc++ and libstdc++.

Differential Revision: https://reviews.llvm.org/D37631

llvm-svn: 322604
2018-01-17 00:42:48 +00:00
Kostya Serebryany e9ed2327b6 [libFuzzer] change the strategy for -experimental_len_control to grow max_len slower
llvm-svn: 320531
2017-12-12 23:11:28 +00:00