1//===- FuzzerExtraCounters.cpp - Extra coverage counters ------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// Extra coverage counters defined by user code. 9//===----------------------------------------------------------------------===// 10 11#include "FuzzerDefs.h" 12 13#if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FREEBSD || \ 14 LIBFUZZER_OPENBSD || LIBFUZZER_FUCHSIA || LIBFUZZER_EMSCRIPTEN 15__attribute__((weak)) extern uint8_t __start___libfuzzer_extra_counters; 16__attribute__((weak)) extern uint8_t __stop___libfuzzer_extra_counters; 17 18namespace fuzzer { 19uint8_t *ExtraCountersBegin() { return &__start___libfuzzer_extra_counters; } 20uint8_t *ExtraCountersEnd() { return &__stop___libfuzzer_extra_counters; } 21ATTRIBUTE_NO_SANITIZE_ALL 22void ClearExtraCounters() { // hand-written memset, don't asan-ify. 23 uintptr_t *Beg = reinterpret_cast<uintptr_t*>(ExtraCountersBegin()); 24 uintptr_t *End = reinterpret_cast<uintptr_t*>(ExtraCountersEnd()); 25 for (; Beg < End; Beg++) { 26 *Beg = 0; 27 __asm__ __volatile__("" : : : "memory"); 28 } 29} 30 31} // namespace fuzzer 32 33#else 34// TODO: implement for other platforms. 35namespace fuzzer { 36uint8_t *ExtraCountersBegin() { return nullptr; } 37uint8_t *ExtraCountersEnd() { return nullptr; } 38void ClearExtraCounters() {} 39} // namespace fuzzer 40 41#endif 42