Commit Graph

11 Commits

Author SHA1 Message Date
Jake Ehrlich 4b23c24bc8 [libFuzzer] Always print DSO map on Fuchsia libFuzzer launch
Fuchsia doesn't have /proc/id/maps, so it relies on the kernel logging system
to provide the DSO map to be able to symbolize in the context of ASLR. The DSO
map is logged automatically on Fuchsia when encountering a crash or writing to
the sanitizer log for the first time in a process. There are several cases
where libFuzzer doesn't encounter a crash, e.g. on timeouts, OOMs, and when
configured to print new PCs as they become covered, to name a few. Therefore,
this change always writes to the sanitizer log on startup to ensure the DSO map
is available in the log.

Author: aarongreen
Differential Revision: https://reviews.llvm.org/D66233

llvm-svn: 372056
2019-09-17 00:34:41 +00:00
Max Moroz f1b0a93e3a [compiler-rt] Move FDP to include/fuzzer/FuzzedDataProvider.h for easier use.
Summary:
FuzzedDataProvider is a helper class for writing fuzz targets that fuzz
multple inputs simultaneously. The header is supposed to be used for fuzzing
engine agnostic fuzz targets (i.e. the same target can be used with libFuzzer,
AFL, honggfuzz, and other engines). The common thing though is that fuzz targets
are typically compiled with clang, as it provides all sanitizers as well as
different coverage instrumentation modes. Therefore, making this FDP class a
part of the compiler-rt installation package would make it easier to develop
and distribute fuzz targets across different projects, build systems, etc.
Some context also available in https://github.com/google/oss-fuzz/pull/2547.

This CL does not delete the header from `lib/fuzzer/utils` directory in order to
provide the downstream users some time for a smooth migration to the new
header location.

Reviewers: kcc, morehouse

Reviewed By: morehouse

Subscribers: lebedev.ri, kubamracek, dberris, mgorny, delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D65661

llvm-svn: 367917
2019-08-05 19:55:52 +00:00
Max Moroz 374398afb7 [libFuzzer] Fix __sanitizer_print_memory_profile return type in ExtFunctions.def
Summary:
Looks like a typo, as that function actually returns void and is used
as such in libFuzzer code as well.

Reviewers: kcc, Dor1s

Reviewed By: Dor1s

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D65160

llvm-svn: 366834
2019-07-23 18:26:53 +00:00
Matt Morehouse 3478494c1f [libFuzzer] Unpoison parameters before calling user callback.
Summary:
Fixes an MSan false positive when compiling with
-fsanitize=memory,fuzzer.

See https://github.com/google/oss-fuzz/issues/2369 for more details.

Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits, metzman, eugenis

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61753

llvm-svn: 360390
2019-05-09 22:48:46 +00:00
David L. Jones 6218b8e783 [Fuzzer] Fix function prototype in fuzzer::ExternalFunctions. [NFC]
The __sanitizer_acquire_crash_state function has int return type, but the
fuzzer's external function definitions give it bool.

Places where __sanitizer_acquire_crash_state is declared:

  include/sanitizer_common/sanitizer_interface_defs.h
  lib/sanitizer_common/sanitizer_interface_internal.h
  lib/sanitizer_common/sanitizer_common.cc
  lib/fuzzer/FuzzerExtFunctions.def (this is the only bool)

llvm-svn: 353596
2019-02-09 01:45:29 +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
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 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
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
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