darling-JavaScriptCore/runtime/FuzzerPredictions.cpp

106 lines
4.5 KiB
C++

/*
* Copyright (C) 2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "FuzzerPredictions.h"
namespace JSC {
static String readFileIntoString(const char* fileName)
{
FILE* file = fopen(fileName, "r");
RELEASE_ASSERT_WITH_MESSAGE(file, "Failed to open file %s", fileName);
RELEASE_ASSERT(fseek(file, 0, SEEK_END) != -1);
long bufferCapacity = ftell(file);
RELEASE_ASSERT(bufferCapacity != -1);
RELEASE_ASSERT(fseek(file, 0, SEEK_SET) != -1);
Vector<char> buffer;
buffer.resize(bufferCapacity);
size_t readSize = fread(buffer.data(), 1, buffer.size(), file);
fclose(file);
RELEASE_ASSERT(readSize == buffer.size());
return String(buffer.data(), buffer.size());
}
FuzzerPredictions::FuzzerPredictions(const char* filename)
{
RELEASE_ASSERT_WITH_MESSAGE(filename, "prediction file must be specified using --fuzzerPredictionsFile=");
String predictions = readFileIntoString(filename);
const Vector<String>& lines = predictions.split('\n');
for (const auto& line : lines) {
// Predictions are stored in a text file, one prediction per line in the colon delimited format:
// <lookup key>:<prediction in hex without leading 0x>
// The lookup key is a pipe separated string with the format:
// <filename>|<opcode>|<start offset>|<end offset>
// The start and end offsets are 7-bit unsigned integers.
// If start offset > 127, then both start and end offsets are 0.
// If end offset > 127, then the end offset is 0.
// Example predictions:
// foo.js|op_construct|702|721:1000084
// foo.js|op_call|748|760:408800
// foo.js|op_bitnot|770|770:280000000
// Predictions can be generated using PredictionFileCreatingFuzzerAgent.
// Some opcodes are aliased together to make generating the predictions more straightforward.
// For the aliases see: FileBasedFuzzerAgentBase::opcodeAliasForLookupKey()
// FIXME: The current implementation only supports one prediction per lookup key.
const Vector<String>& lineParts = line.split(':');
RELEASE_ASSERT_WITH_MESSAGE(lineParts.size() == 2, "Expected line with two parts delimited by a colon. Found line with %zu parts.", lineParts.size());
const String& lookupKey = lineParts[0];
const String& predictionString = lineParts[1];
bool ok;
SpeculatedType prediction = predictionString.toUInt64Strict(&ok, 0x10);
RELEASE_ASSERT_WITH_MESSAGE(ok, "Could not parse prediction from '%s'", predictionString.utf8().data());
RELEASE_ASSERT(speculationChecked(prediction, SpecFullTop));
m_predictions.set(lookupKey, prediction);
}
}
Optional<SpeculatedType> FuzzerPredictions::predictionFor(const String& key)
{
auto it = m_predictions.find(key);
if (it == m_predictions.end())
return WTF::nullopt;
return it->value;
}
FuzzerPredictions& ensureGlobalFuzzerPredictions()
{
static LazyNeverDestroyed<FuzzerPredictions> fuzzerPredictions;
static std::once_flag initializeFuzzerPredictionsFlag;
std::call_once(initializeFuzzerPredictionsFlag, [] {
const char* fuzzerPredictionsFilename = Options::fuzzerPredictionsFile();
fuzzerPredictions.construct(fuzzerPredictionsFilename);
});
return fuzzerPredictions;
}
} // namespace JSC