Mercurial > hg
view contrib/fuzz/xdiff.cc @ 41139:2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
This is the recommended approach from [0], and limiting the input was
suggested in https://github.com/google/oss-fuzz/issues/2076 when
discussing our broken coverage build.
0: https://github.com/google/oss-fuzz/blob/master/docs/new_project_guide.md#custom-libfuzzer-options-for-clusterfuzz
Differential Revision: https://phab.mercurial-scm.org/D5525
author | Augie Fackler <augie@google.com> |
---|---|
date | Tue, 08 Jan 2019 10:31:10 -0500 |
parents | fa0ddd5e8fff |
children | 78df32a8b6f4 |
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/* * xdiff.cc - fuzzer harness for thirdparty/xdiff * * Copyright 2018, Google Inc. * * This software may be used and distributed according to the terms of * the GNU General Public License, incorporated herein by reference. */ #include "thirdparty/xdiff/xdiff.h" #include <inttypes.h> #include <stdlib.h> #include "fuzzutil.h" extern "C" { int hunk_consumer(long a1, long a2, long b1, long b2, void *priv) { // TODO: probably also test returning -1 from this when things break? return 0; } int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { // Don't allow fuzzer inputs larger than 100k, since we'll just bog // down and not accomplish much. if (Size > 100000) { return 0; } auto maybe_inputs = SplitInputs(Data, Size); if (!maybe_inputs) { return 0; } auto inputs = std::move(maybe_inputs.value()); mmfile_t a, b; a.ptr = inputs.left.get(); a.size = inputs.left_size; b.ptr = inputs.right.get(); b.size = inputs.right_size; xpparam_t xpp = { XDF_INDENT_HEURISTIC, /* flags */ }; xdemitconf_t xecfg = { XDL_EMIT_BDIFFHUNK, /* flags */ hunk_consumer, /* hunk_consume_func */ }; xdemitcb_t ecb = { NULL, /* priv */ }; xdl_diff(&a, &b, &xpp, &xecfg, &ecb); return 0; // Non-zero return values are reserved for future use. } #ifdef HG_FUZZER_INCLUDE_MAIN int main(int argc, char **argv) { const char data[] = "asdf"; return LLVMFuzzerTestOneInput((const uint8_t *)data, 4); } #endif } // extern "C"