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author | thegeorg <thegeorg@yandex-team.com> | 2022-11-07 19:34:08 +0300 |
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committer | thegeorg <thegeorg@yandex-team.com> | 2022-11-07 19:34:08 +0300 |
commit | 50f76e264c70a223a34b24aa59e97bff97128f4c (patch) | |
tree | e604247a10f09df6158c172577b9bfa431f1e1b5 /contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp | |
parent | 278a58c5af63dbd7f7a6d8b8d92dc246651242da (diff) | |
download | ydb-50f76e264c70a223a34b24aa59e97bff97128f4c.tar.gz |
Switch fuzz tests to contrib/libs/libfuzzer
Diffstat (limited to 'contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp')
-rw-r--r-- | contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp b/contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp new file mode 100644 index 0000000000..102f5febda --- /dev/null +++ b/contrib/libs/libfuzzer/FuzzerExtraCountersWindows.cpp @@ -0,0 +1,80 @@ +//===- FuzzerExtraCountersWindows.cpp - Extra coverage counters for Win32 -===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// Extra coverage counters defined by user code for Windows. +//===----------------------------------------------------------------------===// + +#include "FuzzerPlatform.h" +#include <cstdint> + +#if LIBFUZZER_WINDOWS +#include <windows.h> + +namespace fuzzer { + +// +// The __start___libfuzzer_extra_counters variable is align 16, size 16 to +// ensure the padding between it and the next variable in this section (either +// __libfuzzer_extra_counters or __stop___libfuzzer_extra_counters) will be +// located at (__start___libfuzzer_extra_counters + +// sizeof(__start___libfuzzer_extra_counters)). Otherwise, the calculation of +// (stop - (start + sizeof(start))) might be skewed. +// +// The section name, __libfuzzer_extra_countaaa ends with "aaa", so it sorts +// before __libfuzzer_extra_counters alphabetically. We want the start symbol to +// be placed in the section just before the user supplied counters (if present). +// +#pragma section(".data$__libfuzzer_extra_countaaa") +ATTRIBUTE_ALIGNED(16) +__declspec(allocate(".data$__libfuzzer_extra_countaaa")) uint8_t + __start___libfuzzer_extra_counters[16] = {0}; + +// +// Example of what the user-supplied counters should look like. First, the +// pragma to create the section name. It will fall alphabetically between +// ".data$__libfuzzer_extra_countaaa" and ".data$__libfuzzer_extra_countzzz". +// Next, the declspec to allocate the variable inside the specified section. +// Finally, some array, struct, whatever that is used to track the counter data. +// The size of this variable is computed at runtime by finding the difference of +// __stop___libfuzzer_extra_counters and __start___libfuzzer_extra_counters + +// sizeof(__start___libfuzzer_extra_counters). +// + +// +// #pragma section(".data$__libfuzzer_extra_counters") +// __declspec(allocate(".data$__libfuzzer_extra_counters")) +// uint8_t any_name_variable[64 * 1024]; +// + +// +// Here, the section name, __libfuzzer_extra_countzzz ends with "zzz", so it +// sorts after __libfuzzer_extra_counters alphabetically. We want the stop +// symbol to be placed in the section just after the user supplied counters (if +// present). Align to 1 so there isn't any padding placed between this and the +// previous variable. +// +#pragma section(".data$__libfuzzer_extra_countzzz") +ATTRIBUTE_ALIGNED(1) +__declspec(allocate(".data$__libfuzzer_extra_countzzz")) uint8_t + __stop___libfuzzer_extra_counters = 0; + +uint8_t *ExtraCountersBegin() { + return __start___libfuzzer_extra_counters + + sizeof(__start___libfuzzer_extra_counters); +} + +uint8_t *ExtraCountersEnd() { return &__stop___libfuzzer_extra_counters; } + +ATTRIBUTE_NO_SANITIZE_ALL +void ClearExtraCounters() { + uint8_t *Beg = ExtraCountersBegin(); + SecureZeroMemory(Beg, ExtraCountersEnd() - Beg); +} + +} // namespace fuzzer + +#endif |