From 61efe14e21b2c47a848f6d7500ed05af17c64a9a Mon Sep 17 00:00:00 2001 From: Jonas Devlieghere Date: Fri, 25 Mar 2022 09:03:52 -0700 Subject: [PATCH] [lldb] Add a fuzzer for target creation This patch adds a generic fuzzer that interprets inputs as object files and uses them to create a target in lldb. It is very similar to the llvm-dwarfdump fuzzer which found a bunch of issues in libObject. Differential revision: https://reviews.llvm.org/D122461 --- lldb/tools/CMakeLists.txt | 1 + lldb/tools/lldb-fuzzer/CMakeLists.txt | 17 +++++++++ lldb/tools/lldb-fuzzer/lldb-target-fuzzer.cpp | 35 +++++++++++++++++++ lldb/tools/lldb-fuzzer/utils/CMakeLists.txt | 6 ++++ lldb/tools/lldb-fuzzer/utils/TempFile.cpp | 33 +++++++++++++++++ lldb/tools/lldb-fuzzer/utils/TempFile.h | 27 ++++++++++++++ llvm/docs/FuzzingLLVM.rst | 5 +++ 7 files changed, 124 insertions(+) create mode 100644 lldb/tools/lldb-fuzzer/CMakeLists.txt create mode 100644 lldb/tools/lldb-fuzzer/lldb-target-fuzzer.cpp create mode 100644 lldb/tools/lldb-fuzzer/utils/CMakeLists.txt create mode 100644 lldb/tools/lldb-fuzzer/utils/TempFile.cpp create mode 100644 lldb/tools/lldb-fuzzer/utils/TempFile.h diff --git a/lldb/tools/CMakeLists.txt b/lldb/tools/CMakeLists.txt index 1585fd4dc4b9..16a2c7956aef 100644 --- a/lldb/tools/CMakeLists.txt +++ b/lldb/tools/CMakeLists.txt @@ -6,6 +6,7 @@ add_subdirectory(intel-features) # i.e. if a target requires it as dependency. The typical # example is `check-lldb`. So, we pass EXCLUDE_FROM_ALL here. add_subdirectory(lldb-test EXCLUDE_FROM_ALL) +add_subdirectory(lldb-fuzzer EXCLUDE_FROM_ALL) add_lldb_tool_subdirectory(lldb-instr) add_lldb_tool_subdirectory(lldb-vscode) diff --git a/lldb/tools/lldb-fuzzer/CMakeLists.txt b/lldb/tools/lldb-fuzzer/CMakeLists.txt new file mode 100644 index 000000000000..44df5f193b44 --- /dev/null +++ b/lldb/tools/lldb-fuzzer/CMakeLists.txt @@ -0,0 +1,17 @@ +add_subdirectory(utils) + +set(LLVM_LINK_COMPONENTS + Support + ) + +add_llvm_fuzzer(lldb-target-fuzzer + EXCLUDE_FROM_ALL + lldb-target-fuzzer.cpp + ) + +target_link_libraries(lldb-target-fuzzer + PRIVATE + liblldb + lldbFuzzerUtils + ) + diff --git a/lldb/tools/lldb-fuzzer/lldb-target-fuzzer.cpp b/lldb/tools/lldb-fuzzer/lldb-target-fuzzer.cpp new file mode 100644 index 000000000000..82487bb224f0 --- /dev/null +++ b/lldb/tools/lldb-fuzzer/lldb-target-fuzzer.cpp @@ -0,0 +1,35 @@ +//===-- lldb-target-fuzzer.cpp - Fuzz target creation ---------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include + +#include "lldb/API/SBDebugger.h" +#include "lldb/API/SBTarget.h" + +using namespace lldb; +using namespace lldb_fuzzer; +using namespace llvm; + +extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv) { + SBDebugger::Initialize(); + return 0; +} + +extern "C" int LLVMFuzzerTestOneInput(uint8_t *data, size_t size) { + std::unique_ptr file = TempFile::Create(data, size); + if (!file) + return 1; + + SBDebugger debugger = SBDebugger::Create(false); + SBTarget target = debugger.CreateTarget(file->GetPath().data()); + debugger.DeleteTarget(target); + SBDebugger::Destroy(debugger); + SBModule::GarbageCollectAllocatedModules(); + + return 0; +} diff --git a/lldb/tools/lldb-fuzzer/utils/CMakeLists.txt b/lldb/tools/lldb-fuzzer/utils/CMakeLists.txt new file mode 100644 index 000000000000..2c99c79e8aef --- /dev/null +++ b/lldb/tools/lldb-fuzzer/utils/CMakeLists.txt @@ -0,0 +1,6 @@ +add_lldb_library(lldbFuzzerUtils + TempFile.cpp + + LINK_COMPONENTS + Support + ) diff --git a/lldb/tools/lldb-fuzzer/utils/TempFile.cpp b/lldb/tools/lldb-fuzzer/utils/TempFile.cpp new file mode 100644 index 000000000000..c5c16ec19df7 --- /dev/null +++ b/lldb/tools/lldb-fuzzer/utils/TempFile.cpp @@ -0,0 +1,33 @@ +//===-- TempFile.cpp ------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/FileSystem.h" +#include + +using namespace lldb_fuzzer; +using namespace llvm; + +TempFile::~TempFile() { + if (!m_path.empty()) + sys::fs::remove(m_path.str(), true); +} + +std::unique_ptr TempFile::Create(uint8_t *data, size_t size) { + int fd; + std::unique_ptr temp_file = std::make_unique(); + std::error_code ec = sys::fs::createTemporaryFile("lldb-fuzzer", "input", fd, + temp_file->m_path); + if (ec) + return nullptr; + + raw_fd_ostream os(fd, true); + os.write(reinterpret_cast(data), size); + os.close(); + + return temp_file; +} diff --git a/lldb/tools/lldb-fuzzer/utils/TempFile.h b/lldb/tools/lldb-fuzzer/utils/TempFile.h new file mode 100644 index 000000000000..27453b0c62d2 --- /dev/null +++ b/lldb/tools/lldb-fuzzer/utils/TempFile.h @@ -0,0 +1,27 @@ +//===-- TempFile.h ----------------------------------------------*- C++ -*-===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/Support/Error.h" + +namespace lldb_fuzzer { + +class TempFile { +public: + TempFile() = default; + ~TempFile(); + + static std::unique_ptr Create(uint8_t *data, size_t size); + llvm::StringRef GetPath() { return m_path.str(); } + +private: + llvm::SmallString<128> m_path; +}; + +} // namespace lldb_fuzzer diff --git a/llvm/docs/FuzzingLLVM.rst b/llvm/docs/FuzzingLLVM.rst index e471020aab76..6b32eeab1241 100644 --- a/llvm/docs/FuzzingLLVM.rst +++ b/llvm/docs/FuzzingLLVM.rst @@ -158,6 +158,11 @@ compatible with all of libFuzzer's features. See the notes above about .. |LLVM IR fuzzer| replace:: :ref:`structured LLVM IR fuzzer ` +lldb-target-fuzzer +--------------------- + +A |generic fuzzer| that interprets inputs as object files and uses them to +create a target in lldb. Mutators and Input Generators =============================