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 "FuzzerPlatform.h" 12 #include <cstdint> 13 14 #if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FREEBSD || \ 15 LIBFUZZER_FUCHSIA || LIBFUZZER_EMSCRIPTEN 16 __attribute__((weak)) extern uint8_t __start___libfuzzer_extra_counters; 17 __attribute__((weak)) extern uint8_t __stop___libfuzzer_extra_counters; 18 19 namespace fuzzer { 20 uint8_t *ExtraCountersBegin() { return &__start___libfuzzer_extra_counters; } 21 uint8_t *ExtraCountersEnd() { return &__stop___libfuzzer_extra_counters; } 22 ATTRIBUTE_NO_SANITIZE_ALL 23 void ClearExtraCounters() { // hand-written memset, don't asan-ify. 24 uintptr_t *Beg = reinterpret_cast<uintptr_t*>(ExtraCountersBegin()); 25 uintptr_t *End = reinterpret_cast<uintptr_t*>(ExtraCountersEnd()); 26 for (; Beg < End; Beg++) { 27 *Beg = 0; 28 __asm__ __volatile__("" : : : "memory"); 29 } 30 } 31 32 } // namespace fuzzer 33 34 #endif 35