1*4ba319b5SDimitry Andric //===- FuzzerExtraCounters.cpp - Extra coverage counters ------------------===//
2*4ba319b5SDimitry Andric //
3*4ba319b5SDimitry Andric //                     The LLVM Compiler Infrastructure
4*4ba319b5SDimitry Andric //
5*4ba319b5SDimitry Andric // This file is distributed under the University of Illinois Open Source
6*4ba319b5SDimitry Andric // License. See LICENSE.TXT for details.
7*4ba319b5SDimitry Andric //
8*4ba319b5SDimitry Andric //===----------------------------------------------------------------------===//
9*4ba319b5SDimitry Andric // Extra coverage counters defined by user code.
10*4ba319b5SDimitry Andric //===----------------------------------------------------------------------===//
11*4ba319b5SDimitry Andric 
12*4ba319b5SDimitry Andric #include "FuzzerDefs.h"
13*4ba319b5SDimitry Andric 
14*4ba319b5SDimitry Andric #if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FREEBSD ||                \
15*4ba319b5SDimitry Andric     LIBFUZZER_OPENBSD
16*4ba319b5SDimitry Andric __attribute__((weak)) extern uint8_t __start___libfuzzer_extra_counters;
17*4ba319b5SDimitry Andric __attribute__((weak)) extern uint8_t __stop___libfuzzer_extra_counters;
18*4ba319b5SDimitry Andric 
19*4ba319b5SDimitry Andric namespace fuzzer {
ExtraCountersBegin()20*4ba319b5SDimitry Andric uint8_t *ExtraCountersBegin() { return &__start___libfuzzer_extra_counters; }
ExtraCountersEnd()21*4ba319b5SDimitry Andric uint8_t *ExtraCountersEnd() { return &__stop___libfuzzer_extra_counters; }
22*4ba319b5SDimitry Andric ATTRIBUTE_NO_SANITIZE_ALL
ClearExtraCounters()23*4ba319b5SDimitry Andric void ClearExtraCounters() {  // hand-written memset, don't asan-ify.
24*4ba319b5SDimitry Andric   uintptr_t *Beg = reinterpret_cast<uintptr_t*>(ExtraCountersBegin());
25*4ba319b5SDimitry Andric   uintptr_t *End = reinterpret_cast<uintptr_t*>(ExtraCountersEnd());
26*4ba319b5SDimitry Andric   for (; Beg < End; Beg++) {
27*4ba319b5SDimitry Andric     *Beg = 0;
28*4ba319b5SDimitry Andric     __asm__ __volatile__("" : : : "memory");
29*4ba319b5SDimitry Andric   }
30*4ba319b5SDimitry Andric }
31*4ba319b5SDimitry Andric 
32*4ba319b5SDimitry Andric }  // namespace fuzzer
33*4ba319b5SDimitry Andric 
34*4ba319b5SDimitry Andric #else
35*4ba319b5SDimitry Andric // TODO: implement for other platforms.
36*4ba319b5SDimitry Andric namespace fuzzer {
ExtraCountersBegin()37*4ba319b5SDimitry Andric uint8_t *ExtraCountersBegin() { return nullptr; }
ExtraCountersEnd()38*4ba319b5SDimitry Andric uint8_t *ExtraCountersEnd() { return nullptr; }
ClearExtraCounters()39*4ba319b5SDimitry Andric void ClearExtraCounters() {}
40*4ba319b5SDimitry Andric }  // namespace fuzzer
41*4ba319b5SDimitry Andric 
42*4ba319b5SDimitry Andric #endif
43