platform_system_core/trusty/fuzz/counters.cpp

96 lines
2.5 KiB
C++

/*
* Copyright (C) 2020 The Android Open Sourete Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "trusty-fuzz-counters"
#include <FuzzerDefs.h>
#include <trusty/fuzz/counters.h>
#include <android-base/logging.h>
#include <log/log.h>
#include <trusty/coverage/coverage.h>
#include <trusty/coverage/tipc.h>
using android::base::ErrnoError;
using android::base::Error;
using android::base::Result;
/*
* We don't know how many counters the coverage record will contain. So, eyeball
* the size of this section.
*/
static const size_t kMaxNumCounters = 0x8000;
__attribute__((section("__libfuzzer_extra_counters"))) volatile uint8_t counters[kMaxNumCounters];
namespace android {
namespace trusty {
namespace fuzz {
ExtraCounters::ExtraCounters(coverage::CoverageRecord* record) : record_(record) {
if (!record_->IsOpen()) {
return;
}
assert(fuzzer::ExtraCountersBegin());
assert(fuzzer::ExtraCountersEnd());
volatile uint8_t* begin = NULL;
volatile uint8_t* end = NULL;
record_->GetRawCounts(&begin, &end);
assert(end - begin <= sizeof(counters));
}
ExtraCounters::~ExtraCounters() {
if (!record_->IsOpen()) {
return;
}
Flush();
}
void ExtraCounters::Reset() {
if (!record_->IsOpen()) {
return;
}
record_->ResetCounts();
fuzzer::ClearExtraCounters();
}
void ExtraCounters::Flush() {
volatile uint8_t* begin = NULL;
volatile uint8_t* end = NULL;
record_->GetRawCounts(&begin, &end);
if (!begin || !end) {
ALOGE("Could not get raw counts from coverage record\n");
return;
}
size_t num_counters = end - begin;
if (num_counters > kMaxNumCounters) {
ALOGE("Too many counters (%zu) to fit in the extra counters section!\n", num_counters);
num_counters = kMaxNumCounters;
}
for (size_t i = 0; i < num_counters; i++) {
*(counters + i) = *(begin + i);
}
}
} // namespace fuzz
} // namespace trusty
} // namespace android