| //===-- asan_win.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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is a part of AddressSanitizer, an address sanity checker. |
| // |
| // Windows-specific details. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_common/sanitizer_platform.h" |
| #if SANITIZER_WINDOWS |
| #define WIN32_LEAN_AND_MEAN |
| #include <windows.h> |
| |
| #include <stdlib.h> |
| |
| #include "asan_interceptors.h" |
| #include "asan_internal.h" |
| #include "asan_mapping.h" |
| #include "asan_report.h" |
| #include "asan_stack.h" |
| #include "asan_thread.h" |
| #include "sanitizer_common/sanitizer_libc.h" |
| #include "sanitizer_common/sanitizer_mutex.h" |
| #include "sanitizer_common/sanitizer_win.h" |
| #include "sanitizer_common/sanitizer_win_defs.h" |
| |
| using namespace __asan; |
| |
| extern "C" { |
| SANITIZER_INTERFACE_ATTRIBUTE |
| int __asan_should_detect_stack_use_after_return() { |
| __asan_init(); |
| return __asan_option_detect_stack_use_after_return; |
| } |
| |
| SANITIZER_INTERFACE_ATTRIBUTE |
| uptr __asan_get_shadow_memory_dynamic_address() { |
| __asan_init(); |
| return __asan_shadow_memory_dynamic_address; |
| } |
| } // extern "C" |
| |
| // ---------------------- Windows-specific interceptors ---------------- {{{ |
| static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler; |
| static LPTOP_LEVEL_EXCEPTION_FILTER user_seh_handler; |
| |
| extern "C" SANITIZER_INTERFACE_ATTRIBUTE |
| long __asan_unhandled_exception_filter(EXCEPTION_POINTERS *info) { |
| EXCEPTION_RECORD *exception_record = info->ExceptionRecord; |
| CONTEXT *context = info->ContextRecord; |
| |
| // FIXME: Handle EXCEPTION_STACK_OVERFLOW here. |
| |
| SignalContext sig(exception_record, context); |
| ReportDeadlySignal(sig); |
| UNREACHABLE("returned from reporting deadly signal"); |
| } |
| |
| // Wrapper SEH Handler. If the exception should be handled by asan, we call |
| // __asan_unhandled_exception_filter, otherwise, we execute the user provided |
| // exception handler or the default. |
| static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) { |
| DWORD exception_code = info->ExceptionRecord->ExceptionCode; |
| if (__sanitizer::IsHandledDeadlyException(exception_code)) |
| return __asan_unhandled_exception_filter(info); |
| if (user_seh_handler) |
| return user_seh_handler(info); |
| // Bubble out to the default exception filter. |
| if (default_seh_handler) |
| return default_seh_handler(info); |
| return EXCEPTION_CONTINUE_SEARCH; |
| } |
| |
| INTERCEPTOR_WINAPI(LPTOP_LEVEL_EXCEPTION_FILTER, SetUnhandledExceptionFilter, |
| LPTOP_LEVEL_EXCEPTION_FILTER ExceptionFilter) { |
| CHECK(REAL(SetUnhandledExceptionFilter)); |
| if (ExceptionFilter == &SEHHandler) |
| return REAL(SetUnhandledExceptionFilter)(ExceptionFilter); |
| // We record the user provided exception handler to be called for all the |
| // exceptions unhandled by asan. |
| Swap(ExceptionFilter, user_seh_handler); |
| return ExceptionFilter; |
| } |
| |
| INTERCEPTOR_WINAPI(void, RtlRaiseException, EXCEPTION_RECORD *ExceptionRecord) { |
| CHECK(REAL(RtlRaiseException)); |
| // This is a noreturn function, unless it's one of the exceptions raised to |
| // communicate with the debugger, such as the one from OutputDebugString. |
| if (ExceptionRecord->ExceptionCode != DBG_PRINTEXCEPTION_C) |
| __asan_handle_no_return(); |
| REAL(RtlRaiseException)(ExceptionRecord); |
| } |
| |
| INTERCEPTOR_WINAPI(void, RaiseException, void *a, void *b, void *c, void *d) { |
| CHECK(REAL(RaiseException)); |
| __asan_handle_no_return(); |
| REAL(RaiseException)(a, b, c, d); |
| } |
| |
| #ifdef _WIN64 |
| |
| INTERCEPTOR_WINAPI(EXCEPTION_DISPOSITION, __C_specific_handler, |
| _EXCEPTION_RECORD *a, void *b, _CONTEXT *c, |
| _DISPATCHER_CONTEXT *d) { |
| CHECK(REAL(__C_specific_handler)); |
| __asan_handle_no_return(); |
| return REAL(__C_specific_handler)(a, b, c, d); |
| } |
| |
| #else |
| |
| INTERCEPTOR(int, _except_handler3, void *a, void *b, void *c, void *d) { |
| CHECK(REAL(_except_handler3)); |
| __asan_handle_no_return(); |
| return REAL(_except_handler3)(a, b, c, d); |
| } |
| |
| #if ASAN_DYNAMIC |
| // This handler is named differently in -MT and -MD CRTs. |
| #define _except_handler4 _except_handler4_common |
| #endif |
| INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) { |
| CHECK(REAL(_except_handler4)); |
| __asan_handle_no_return(); |
| return REAL(_except_handler4)(a, b, c, d); |
| } |
| #endif |
| |
| static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) { |
| AsanThread *t = (AsanThread *)arg; |
| SetCurrentThread(t); |
| return t->ThreadStart(GetTid(), /* signal_thread_is_registered */ nullptr); |
| } |
| |
| INTERCEPTOR_WINAPI(HANDLE, CreateThread, LPSECURITY_ATTRIBUTES security, |
| SIZE_T stack_size, LPTHREAD_START_ROUTINE start_routine, |
| void *arg, DWORD thr_flags, DWORD *tid) { |
| // Strict init-order checking is thread-hostile. |
| if (flags()->strict_init_order) |
| StopInitOrderChecking(); |
| GET_STACK_TRACE_THREAD; |
| // FIXME: The CreateThread interceptor is not the same as a pthread_create |
| // one. This is a bandaid fix for PR22025. |
| bool detached = false; // FIXME: how can we determine it on Windows? |
| u32 current_tid = GetCurrentTidOrInvalid(); |
| AsanThread *t = |
| AsanThread::Create(start_routine, arg, current_tid, &stack, detached); |
| return REAL(CreateThread)(security, stack_size, asan_thread_start, t, |
| thr_flags, tid); |
| } |
| |
| // }}} |
| |
| namespace __asan { |
| |
| void InitializePlatformInterceptors() { |
| // The interceptors were not designed to be removable, so we have to keep this |
| // module alive for the life of the process. |
| HMODULE pinned; |
| CHECK(GetModuleHandleExW( |
| GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_PIN, |
| (LPCWSTR)&InitializePlatformInterceptors, &pinned)); |
| |
| ASAN_INTERCEPT_FUNC(CreateThread); |
| ASAN_INTERCEPT_FUNC(SetUnhandledExceptionFilter); |
| |
| #ifdef _WIN64 |
| ASAN_INTERCEPT_FUNC(__C_specific_handler); |
| #else |
| ASAN_INTERCEPT_FUNC(_except_handler3); |
| ASAN_INTERCEPT_FUNC(_except_handler4); |
| #endif |
| |
| // Try to intercept kernel32!RaiseException, and if that fails, intercept |
| // ntdll!RtlRaiseException instead. |
| if (!::__interception::OverrideFunction("RaiseException", |
| (uptr)WRAP(RaiseException), |
| (uptr *)&REAL(RaiseException))) { |
| CHECK(::__interception::OverrideFunction("RtlRaiseException", |
| (uptr)WRAP(RtlRaiseException), |
| (uptr *)&REAL(RtlRaiseException))); |
| } |
| } |
| |
| void AsanApplyToGlobals(globals_op_fptr op, const void *needle) { |
| UNIMPLEMENTED(); |
| } |
| |
| // ---------------------- TSD ---------------- {{{ |
| static bool tsd_key_inited = false; |
| |
| static __declspec(thread) void *fake_tsd = 0; |
| |
| // https://docs.microsoft.com/en-us/windows/desktop/api/winternl/ns-winternl-_teb |
| // "[This structure may be altered in future versions of Windows. Applications |
| // should use the alternate functions listed in this topic.]" |
| typedef struct _TEB { |
| PVOID Reserved1[12]; |
| // PVOID ThreadLocalStoragePointer; is here, at the last field in Reserved1. |
| PVOID ProcessEnvironmentBlock; |
| PVOID Reserved2[399]; |
| BYTE Reserved3[1952]; |
| PVOID TlsSlots[64]; |
| BYTE Reserved4[8]; |
| PVOID Reserved5[26]; |
| PVOID ReservedForOle; |
| PVOID Reserved6[4]; |
| PVOID TlsExpansionSlots; |
| } TEB, *PTEB; |
| |
| constexpr size_t TEB_RESERVED_FIELDS_THREAD_LOCAL_STORAGE_OFFSET = 11; |
| BOOL IsTlsInitialized() { |
| PTEB teb = (PTEB)NtCurrentTeb(); |
| return teb->Reserved1[TEB_RESERVED_FIELDS_THREAD_LOCAL_STORAGE_OFFSET] != |
| nullptr; |
| } |
| |
| void AsanTSDInit(void (*destructor)(void *tsd)) { |
| // FIXME: we're ignoring the destructor for now. |
| tsd_key_inited = true; |
| } |
| |
| void *AsanTSDGet() { |
| CHECK(tsd_key_inited); |
| return IsTlsInitialized() ? fake_tsd : nullptr; |
| } |
| |
| void AsanTSDSet(void *tsd) { |
| CHECK(tsd_key_inited); |
| fake_tsd = tsd; |
| } |
| |
| void PlatformTSDDtor(void *tsd) { AsanThread::TSDDtor(tsd); } |
| // }}} |
| |
| // ---------------------- Various stuff ---------------- {{{ |
| void *AsanDoesNotSupportStaticLinkage() { |
| #if defined(_DEBUG) |
| #error Please build the runtime with a non-debug CRT: /MD or /MT |
| #endif |
| return 0; |
| } |
| |
| uptr FindDynamicShadowStart() { |
| uptr granularity = GetMmapGranularity(); |
| uptr alignment = 8 * granularity; |
| uptr left_padding = granularity; |
| uptr space_size = kHighShadowEnd + left_padding; |
| uptr shadow_start = FindAvailableMemoryRange(space_size, alignment, |
| granularity, nullptr, nullptr); |
| CHECK_NE((uptr)0, shadow_start); |
| CHECK(IsAligned(shadow_start, alignment)); |
| return shadow_start; |
| } |
| |
| void AsanCheckDynamicRTPrereqs() {} |
| |
| void AsanCheckIncompatibleRT() {} |
| |
| void ReadContextStack(void *context, uptr *stack, uptr *ssize) { |
| UNIMPLEMENTED(); |
| } |
| |
| void AsanOnDeadlySignal(int, void *siginfo, void *context) { UNIMPLEMENTED(); } |
| |
| #if SANITIZER_WINDOWS64 |
| // Exception handler for dealing with shadow memory. |
| static LONG CALLBACK |
| ShadowExceptionHandler(PEXCEPTION_POINTERS exception_pointers) { |
| uptr page_size = GetPageSizeCached(); |
| // Only handle access violations. |
| if (exception_pointers->ExceptionRecord->ExceptionCode != |
| EXCEPTION_ACCESS_VIOLATION || |
| exception_pointers->ExceptionRecord->NumberParameters < 2) { |
| __asan_handle_no_return(); |
| return EXCEPTION_CONTINUE_SEARCH; |
| } |
| |
| // Only handle access violations that land within the shadow memory. |
| uptr addr = |
| (uptr)(exception_pointers->ExceptionRecord->ExceptionInformation[1]); |
| |
| // Check valid shadow range. |
| if (!AddrIsInShadow(addr)) { |
| __asan_handle_no_return(); |
| return EXCEPTION_CONTINUE_SEARCH; |
| } |
| |
| // This is an access violation while trying to read from the shadow. Commit |
| // the relevant page and let execution continue. |
| |
| // Determine the address of the page that is being accessed. |
| uptr page = RoundDownTo(addr, page_size); |
| |
| // Commit the page. |
| uptr result = |
| (uptr)::VirtualAlloc((LPVOID)page, page_size, MEM_COMMIT, PAGE_READWRITE); |
| if (result != page) |
| return EXCEPTION_CONTINUE_SEARCH; |
| |
| // The page mapping succeeded, so continue execution as usual. |
| return EXCEPTION_CONTINUE_EXECUTION; |
| } |
| |
| #endif |
| |
| void InitializePlatformExceptionHandlers() { |
| #if SANITIZER_WINDOWS64 |
| // On Win64, we map memory on demand with access violation handler. |
| // Install our exception handler. |
| CHECK(AddVectoredExceptionHandler(TRUE, &ShadowExceptionHandler)); |
| #endif |
| } |
| |
| bool IsSystemHeapAddress(uptr addr) { |
| return ::HeapValidate(GetProcessHeap(), 0, (void *)addr) != FALSE; |
| } |
| |
| // We want to install our own exception handler (EH) to print helpful reports |
| // on access violations and whatnot. Unfortunately, the CRT initializers assume |
| // they are run before any user code and drop any previously-installed EHs on |
| // the floor, so we can't install our handler inside __asan_init. |
| // (See crt0dat.c in the CRT sources for the details) |
| // |
| // Things get even more complicated with the dynamic runtime, as it finishes its |
| // initialization before the .exe module CRT begins to initialize. |
| // |
| // For the static runtime (-MT), it's enough to put a callback to |
| // __asan_set_seh_filter in the last section for C initializers. |
| // |
| // For the dynamic runtime (-MD), we want link the same |
| // asan_dynamic_runtime_thunk.lib to all the modules, thus __asan_set_seh_filter |
| // will be called for each instrumented module. This ensures that at least one |
| // __asan_set_seh_filter call happens after the .exe module CRT is initialized. |
| extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __asan_set_seh_filter() { |
| // We should only store the previous handler if it's not our own handler in |
| // order to avoid loops in the EH chain. |
| auto prev_seh_handler = SetUnhandledExceptionFilter(SEHHandler); |
| if (prev_seh_handler != &SEHHandler) |
| default_seh_handler = prev_seh_handler; |
| return 0; |
| } |
| |
| bool HandleDlopenInit() { |
| // Not supported on this platform. |
| static_assert(!SANITIZER_SUPPORTS_INIT_FOR_DLOPEN, |
| "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be false"); |
| return false; |
| } |
| |
| #if !ASAN_DYNAMIC |
| // The CRT runs initializers in this order: |
| // - C initializers, from XIA to XIZ |
| // - C++ initializers, from XCA to XCZ |
| // Prior to 2015, the CRT set the unhandled exception filter at priority XIY, |
| // near the end of C initialization. Starting in 2015, it was moved to the |
| // beginning of C++ initialization. We set our priority to XCAB to run |
| // immediately after the CRT runs. This way, our exception filter is called |
| // first and we can delegate to their filter if appropriate. |
| #pragma section(".CRT$XCAB", long, read) |
| __declspec(allocate(".CRT$XCAB")) int (*__intercept_seh)() = |
| __asan_set_seh_filter; |
| |
| // Piggyback on the TLS initialization callback directory to initialize asan as |
| // early as possible. Initializers in .CRT$XL* are called directly by ntdll, |
| // which run before the CRT. Users also add code to .CRT$XLC, so it's important |
| // to run our initializers first. |
| static void NTAPI asan_thread_init(void *module, DWORD reason, void *reserved) { |
| if (reason == DLL_PROCESS_ATTACH) |
| __asan_init(); |
| } |
| |
| #pragma section(".CRT$XLAB", long, read) |
| __declspec(allocate(".CRT$XLAB")) void(NTAPI *__asan_tls_init)( |
| void *, unsigned long, void *) = asan_thread_init; |
| #endif |
| |
| static void NTAPI asan_thread_exit(void *module, DWORD reason, void *reserved) { |
| if (reason == DLL_THREAD_DETACH) { |
| // Unpoison the thread's stack because the memory may be re-used. |
| NT_TIB *tib = (NT_TIB *)NtCurrentTeb(); |
| uptr stackSize = (uptr)tib->StackBase - (uptr)tib->StackLimit; |
| __asan_unpoison_memory_region(tib->StackLimit, stackSize); |
| } |
| } |
| |
| #pragma section(".CRT$XLY", long, read) |
| __declspec(allocate(".CRT$XLY")) void(NTAPI *__asan_tls_exit)( |
| void *, unsigned long, void *) = asan_thread_exit; |
| |
| WIN_FORCE_LINK(__asan_dso_reg_hook) |
| |
| // }}} |
| } // namespace __asan |
| |
| #endif // SANITIZER_WINDOWS |