//===-- DynamicLoaderMacOSXDYLD.cpp -----------------------------*- 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 "lldb/Breakpoint/StoppointCallbackContext.h" #include "lldb/Core/Debugger.h" #include "lldb/Core/Module.h" #include "lldb/Core/ModuleSpec.h" #include "lldb/Core/PluginManager.h" #include "lldb/Core/Section.h" #include "lldb/Symbol/ClangASTContext.h" #include "lldb/Symbol/Function.h" #include "lldb/Symbol/ObjectFile.h" #include "lldb/Target/ABI.h" #include "lldb/Target/RegisterContext.h" #include "lldb/Target/StackFrame.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" #include "lldb/Target/ThreadPlanRunToAddress.h" #include "lldb/Utility/DataBuffer.h" #include "lldb/Utility/DataBufferHeap.h" #include "lldb/Utility/Log.h" #include "lldb/Utility/State.h" #include "DynamicLoaderDarwin.h" #include "DynamicLoaderMacOSXDYLD.h" #include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h" //#define ENABLE_DEBUG_PRINTF // COMMENT THIS LINE OUT PRIOR TO CHECKIN #ifdef ENABLE_DEBUG_PRINTF #include #define DEBUG_PRINTF(fmt, ...) printf(fmt, ##__VA_ARGS__) #else #define DEBUG_PRINTF(fmt, ...) #endif #ifndef __APPLE__ #include "Utility/UuidCompatibility.h" #else #include #endif using namespace lldb; using namespace lldb_private; // Create an instance of this class. This function is filled into the plugin // info class that gets handed out by the plugin factory and allows the lldb to // instantiate an instance of this class. DynamicLoader *DynamicLoaderMacOSXDYLD::CreateInstance(Process *process, bool force) { bool create = force; if (!create) { create = true; Module *exe_module = process->GetTarget().GetExecutableModulePointer(); if (exe_module) { ObjectFile *object_file = exe_module->GetObjectFile(); if (object_file) { create = (object_file->GetStrata() == ObjectFile::eStrataUser); } } if (create) { const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple(); switch (triple_ref.getOS()) { case llvm::Triple::Darwin: case llvm::Triple::MacOSX: case llvm::Triple::IOS: case llvm::Triple::TvOS: case llvm::Triple::WatchOS: // NEED_BRIDGEOS_TRIPLE case llvm::Triple::BridgeOS: create = triple_ref.getVendor() == llvm::Triple::Apple; break; default: create = false; break; } } } if (UseDYLDSPI(process)) { create = false; } if (create) return new DynamicLoaderMacOSXDYLD(process); return nullptr; } // Constructor DynamicLoaderMacOSXDYLD::DynamicLoaderMacOSXDYLD(Process *process) : DynamicLoaderDarwin(process), m_dyld_all_image_infos_addr(LLDB_INVALID_ADDRESS), m_dyld_all_image_infos(), m_dyld_all_image_infos_stop_id(UINT32_MAX), m_break_id(LLDB_INVALID_BREAK_ID), m_mutex(), m_process_image_addr_is_all_images_infos(false) {} // Destructor DynamicLoaderMacOSXDYLD::~DynamicLoaderMacOSXDYLD() { if (LLDB_BREAK_ID_IS_VALID(m_break_id)) m_process->GetTarget().RemoveBreakpointByID(m_break_id); } bool DynamicLoaderMacOSXDYLD::ProcessDidExec() { std::lock_guard baseclass_guard(GetMutex()); bool did_exec = false; if (m_process) { // If we are stopped after an exec, we will have only one thread... if (m_process->GetThreadList().GetSize() == 1) { // We know if a process has exec'ed if our "m_dyld_all_image_infos_addr" // value differs from the Process' image info address. When a process // execs itself it might cause a change if ASLR is enabled. const addr_t shlib_addr = m_process->GetImageInfoAddress(); if (m_process_image_addr_is_all_images_infos && shlib_addr != m_dyld_all_image_infos_addr) { // The image info address from the process is the // 'dyld_all_image_infos' address and it has changed. did_exec = true; } else if (!m_process_image_addr_is_all_images_infos && shlib_addr == m_dyld.address) { // The image info address from the process is the mach_header address // for dyld and it has changed. did_exec = true; } else { // ASLR might be disabled and dyld could have ended up in the same // location. We should try and detect if we are stopped at // '_dyld_start' ThreadSP thread_sp(m_process->GetThreadList().GetThreadAtIndex(0)); if (thread_sp) { lldb::StackFrameSP frame_sp(thread_sp->GetStackFrameAtIndex(0)); if (frame_sp) { const Symbol *symbol = frame_sp->GetSymbolContext(eSymbolContextSymbol).symbol; if (symbol) { if (symbol->GetName() == "_dyld_start") did_exec = true; } } } } if (did_exec) { m_libpthread_module_wp.reset(); m_pthread_getspecific_addr.Clear(); } } } return did_exec; } // Clear out the state of this class. void DynamicLoaderMacOSXDYLD::DoClear() { std::lock_guard guard(m_mutex); if (LLDB_BREAK_ID_IS_VALID(m_break_id)) m_process->GetTarget().RemoveBreakpointByID(m_break_id); m_dyld_all_image_infos_addr = LLDB_INVALID_ADDRESS; m_dyld_all_image_infos.Clear(); m_break_id = LLDB_INVALID_BREAK_ID; } // Check if we have found DYLD yet bool DynamicLoaderMacOSXDYLD::DidSetNotificationBreakpoint() { return LLDB_BREAK_ID_IS_VALID(m_break_id); } void DynamicLoaderMacOSXDYLD::ClearNotificationBreakpoint() { if (LLDB_BREAK_ID_IS_VALID(m_break_id)) { m_process->GetTarget().RemoveBreakpointByID(m_break_id); } } // Try and figure out where dyld is by first asking the Process if it knows // (which currently calls down in the lldb::Process to get the DYLD info // (available on SnowLeopard only). If that fails, then check in the default // addresses. void DynamicLoaderMacOSXDYLD::DoInitialImageFetch() { if (m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS) { // Check the image info addr as it might point to the mach header for dyld, // or it might point to the dyld_all_image_infos struct const addr_t shlib_addr = m_process->GetImageInfoAddress(); if (shlib_addr != LLDB_INVALID_ADDRESS) { ByteOrder byte_order = m_process->GetTarget().GetArchitecture().GetByteOrder(); uint8_t buf[4]; DataExtractor data(buf, sizeof(buf), byte_order, 4); Status error; if (m_process->ReadMemory(shlib_addr, buf, 4, error) == 4) { lldb::offset_t offset = 0; uint32_t magic = data.GetU32(&offset); switch (magic) { case llvm::MachO::MH_MAGIC: case llvm::MachO::MH_MAGIC_64: case llvm::MachO::MH_CIGAM: case llvm::MachO::MH_CIGAM_64: m_process_image_addr_is_all_images_infos = false; ReadDYLDInfoFromMemoryAndSetNotificationCallback(shlib_addr); return; default: break; } } // Maybe it points to the all image infos? m_dyld_all_image_infos_addr = shlib_addr; m_process_image_addr_is_all_images_infos = true; } } if (m_dyld_all_image_infos_addr != LLDB_INVALID_ADDRESS) { if (ReadAllImageInfosStructure()) { if (m_dyld_all_image_infos.dyldImageLoadAddress != LLDB_INVALID_ADDRESS) ReadDYLDInfoFromMemoryAndSetNotificationCallback( m_dyld_all_image_infos.dyldImageLoadAddress); else ReadDYLDInfoFromMemoryAndSetNotificationCallback( m_dyld_all_image_infos_addr & 0xfffffffffff00000ull); return; } } // Check some default values Module *executable = m_process->GetTarget().GetExecutableModulePointer(); if (executable) { const ArchSpec &exe_arch = executable->GetArchitecture(); if (exe_arch.GetAddressByteSize() == 8) { ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x7fff5fc00000ull); } else if (exe_arch.GetMachine() == llvm::Triple::arm || exe_arch.GetMachine() == llvm::Triple::thumb || exe_arch.GetMachine() == llvm::Triple::aarch64 || exe_arch.GetMachine() == llvm::Triple::aarch64_32) { ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x2fe00000); } else { ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x8fe00000); } } return; } // Assume that dyld is in memory at ADDR and try to parse it's load commands bool DynamicLoaderMacOSXDYLD::ReadDYLDInfoFromMemoryAndSetNotificationCallback( lldb::addr_t addr) { std::lock_guard baseclass_guard(GetMutex()); DataExtractor data; // Load command data static ConstString g_dyld_all_image_infos("dyld_all_image_infos"); if (ReadMachHeader(addr, &m_dyld.header, &data)) { if (m_dyld.header.filetype == llvm::MachO::MH_DYLINKER) { m_dyld.address = addr; ModuleSP dyld_module_sp; if (ParseLoadCommands(data, m_dyld, &m_dyld.file_spec)) { if (m_dyld.file_spec) { UpdateDYLDImageInfoFromNewImageInfo(m_dyld); } } dyld_module_sp = GetDYLDModule(); Target &target = m_process->GetTarget(); if (m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS && dyld_module_sp.get()) { const Symbol *symbol = dyld_module_sp->FindFirstSymbolWithNameAndType( g_dyld_all_image_infos, eSymbolTypeData); if (symbol) m_dyld_all_image_infos_addr = symbol->GetLoadAddress(&target); } // Update all image infos InitializeFromAllImageInfos(); // If we didn't have an executable before, but now we do, then the dyld // module shared pointer might be unique and we may need to add it again // (since Target::SetExecutableModule() will clear the images). So append // the dyld module back to the list if it is /// unique! if (dyld_module_sp) { target.GetImages().AppendIfNeeded(dyld_module_sp); // At this point we should have read in dyld's module, and so we should // set breakpoints in it: ModuleList modules; modules.Append(dyld_module_sp); target.ModulesDidLoad(modules); SetDYLDModule(dyld_module_sp); } return true; } } return false; } bool DynamicLoaderMacOSXDYLD::NeedToDoInitialImageFetch() { return m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS; } // Static callback function that gets called when our DYLD notification // breakpoint gets hit. We update all of our image infos and then let our super // class DynamicLoader class decide if we should stop or not (based on global // preference). bool DynamicLoaderMacOSXDYLD::NotifyBreakpointHit( void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id, lldb::user_id_t break_loc_id) { // Let the event know that the images have changed // DYLD passes three arguments to the notification breakpoint. // Arg1: enum dyld_image_mode mode - 0 = adding, 1 = removing Arg2: uint32_t // infoCount - Number of shared libraries added Arg3: dyld_image_info // info[] - Array of structs of the form: // const struct mach_header // *imageLoadAddress // const char *imageFilePath // uintptr_t imageFileModDate (a time_t) DynamicLoaderMacOSXDYLD *dyld_instance = (DynamicLoaderMacOSXDYLD *)baton; // First step is to see if we've already initialized the all image infos. If // we haven't then this function will do so and return true. In the course // of initializing the all_image_infos it will read the complete current // state, so we don't need to figure out what has changed from the data // passed in to us. ExecutionContext exe_ctx(context->exe_ctx_ref); Process *process = exe_ctx.GetProcessPtr(); // This is a sanity check just in case this dyld_instance is an old dyld // plugin's breakpoint still lying around. if (process != dyld_instance->m_process) return false; if (dyld_instance->InitializeFromAllImageInfos()) return dyld_instance->GetStopWhenImagesChange(); const lldb::ABISP &abi = process->GetABI(); if (abi) { // Build up the value array to store the three arguments given above, then // get the values from the ABI: ClangASTContext *clang_ast_context = ClangASTContext::GetScratch(process->GetTarget()); if (!clang_ast_context) return false; ValueList argument_values; Value input_value; CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); CompilerType clang_uint32_type = clang_ast_context->GetBuiltinTypeForEncodingAndBitSize( lldb::eEncodingUint, 32); input_value.SetValueType(Value::eValueTypeScalar); input_value.SetCompilerType(clang_uint32_type); // input_value.SetContext (Value::eContextTypeClangType, // clang_uint32_type); argument_values.PushValue(input_value); argument_values.PushValue(input_value); input_value.SetCompilerType(clang_void_ptr_type); // input_value.SetContext (Value::eContextTypeClangType, // clang_void_ptr_type); argument_values.PushValue(input_value); if (abi->GetArgumentValues(exe_ctx.GetThreadRef(), argument_values)) { uint32_t dyld_mode = argument_values.GetValueAtIndex(0)->GetScalar().UInt(-1); if (dyld_mode != static_cast(-1)) { // Okay the mode was right, now get the number of elements, and the // array of new elements... uint32_t image_infos_count = argument_values.GetValueAtIndex(1)->GetScalar().UInt(-1); if (image_infos_count != static_cast(-1)) { // Got the number added, now go through the array of added elements, // putting out the mach header address, and adding the image. Note, // I'm not putting in logging here, since the AddModules & // RemoveModules functions do all the logging internally. lldb::addr_t image_infos_addr = argument_values.GetValueAtIndex(2)->GetScalar().ULongLong(); if (dyld_mode == 0) { // This is add: dyld_instance->AddModulesUsingImageInfosAddress(image_infos_addr, image_infos_count); } else { // This is remove: dyld_instance->RemoveModulesUsingImageInfosAddress( image_infos_addr, image_infos_count); } } } } } else { process->GetTarget().GetDebugger().GetAsyncErrorStream()->Printf( "No ABI plugin located for triple %s -- shared libraries will not be " "registered!\n", process->GetTarget().GetArchitecture().GetTriple().getTriple().c_str()); } // Return true to stop the target, false to just let the target run return dyld_instance->GetStopWhenImagesChange(); } bool DynamicLoaderMacOSXDYLD::ReadAllImageInfosStructure() { std::lock_guard guard(m_mutex); // the all image infos is already valid for this process stop ID if (m_process->GetStopID() == m_dyld_all_image_infos_stop_id) return true; m_dyld_all_image_infos.Clear(); if (m_dyld_all_image_infos_addr != LLDB_INVALID_ADDRESS) { ByteOrder byte_order = m_process->GetTarget().GetArchitecture().GetByteOrder(); uint32_t addr_size = m_process->GetTarget().GetArchitecture().GetAddressByteSize(); uint8_t buf[256]; DataExtractor data(buf, sizeof(buf), byte_order, addr_size); lldb::offset_t offset = 0; const size_t count_v2 = sizeof(uint32_t) + // version sizeof(uint32_t) + // infoArrayCount addr_size + // infoArray addr_size + // notification addr_size + // processDetachedFromSharedRegion + // libSystemInitialized + pad addr_size; // dyldImageLoadAddress const size_t count_v11 = count_v2 + addr_size + // jitInfo addr_size + // dyldVersion addr_size + // errorMessage addr_size + // terminationFlags addr_size + // coreSymbolicationShmPage addr_size + // systemOrderFlag addr_size + // uuidArrayCount addr_size + // uuidArray addr_size + // dyldAllImageInfosAddress addr_size + // initialImageCount addr_size + // errorKind addr_size + // errorClientOfDylibPath addr_size + // errorTargetDylibPath addr_size; // errorSymbol const size_t count_v13 = count_v11 + addr_size + // sharedCacheSlide sizeof(uuid_t); // sharedCacheUUID UNUSED_IF_ASSERT_DISABLED(count_v13); assert(sizeof(buf) >= count_v13); Status error; if (m_process->ReadMemory(m_dyld_all_image_infos_addr, buf, 4, error) == 4) { m_dyld_all_image_infos.version = data.GetU32(&offset); // If anything in the high byte is set, we probably got the byte order // incorrect (the process might not have it set correctly yet due to // attaching to a program without a specified file). if (m_dyld_all_image_infos.version & 0xff000000) { // We have guessed the wrong byte order. Swap it and try reading the // version again. if (byte_order == eByteOrderLittle) byte_order = eByteOrderBig; else byte_order = eByteOrderLittle; data.SetByteOrder(byte_order); offset = 0; m_dyld_all_image_infos.version = data.GetU32(&offset); } } else { return false; } const size_t count = (m_dyld_all_image_infos.version >= 11) ? count_v11 : count_v2; const size_t bytes_read = m_process->ReadMemory(m_dyld_all_image_infos_addr, buf, count, error); if (bytes_read == count) { offset = 0; m_dyld_all_image_infos.version = data.GetU32(&offset); m_dyld_all_image_infos.dylib_info_count = data.GetU32(&offset); m_dyld_all_image_infos.dylib_info_addr = data.GetPointer(&offset); m_dyld_all_image_infos.notification = data.GetPointer(&offset); m_dyld_all_image_infos.processDetachedFromSharedRegion = data.GetU8(&offset); m_dyld_all_image_infos.libSystemInitialized = data.GetU8(&offset); // Adjust for padding. offset += addr_size - 2; m_dyld_all_image_infos.dyldImageLoadAddress = data.GetPointer(&offset); if (m_dyld_all_image_infos.version >= 11) { offset += addr_size * 8; uint64_t dyld_all_image_infos_addr = data.GetPointer(&offset); // When we started, we were given the actual address of the // all_image_infos struct (probably via TASK_DYLD_INFO) in memory - // this address is stored in m_dyld_all_image_infos_addr and is the // most accurate address we have. // We read the dyld_all_image_infos struct from memory; it contains its // own address. If the address in the struct does not match the actual // address, the dyld we're looking at has been loaded at a different // location (slid) from where it intended to load. The addresses in // the dyld_all_image_infos struct are the original, non-slid // addresses, and need to be adjusted. Most importantly the address of // dyld and the notification address need to be adjusted. if (dyld_all_image_infos_addr != m_dyld_all_image_infos_addr) { uint64_t image_infos_offset = dyld_all_image_infos_addr - m_dyld_all_image_infos.dyldImageLoadAddress; uint64_t notification_offset = m_dyld_all_image_infos.notification - m_dyld_all_image_infos.dyldImageLoadAddress; m_dyld_all_image_infos.dyldImageLoadAddress = m_dyld_all_image_infos_addr - image_infos_offset; m_dyld_all_image_infos.notification = m_dyld_all_image_infos.dyldImageLoadAddress + notification_offset; } } m_dyld_all_image_infos_stop_id = m_process->GetStopID(); return true; } } return false; } bool DynamicLoaderMacOSXDYLD::AddModulesUsingImageInfosAddress( lldb::addr_t image_infos_addr, uint32_t image_infos_count) { ImageInfo::collection image_infos; Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); LLDB_LOGF(log, "Adding %d modules.\n", image_infos_count); std::lock_guard guard(m_mutex); std::lock_guard baseclass_guard(GetMutex()); if (m_process->GetStopID() == m_dyld_image_infos_stop_id) return true; StructuredData::ObjectSP image_infos_json_sp = m_process->GetLoadedDynamicLibrariesInfos(image_infos_addr, image_infos_count); if (image_infos_json_sp.get() && image_infos_json_sp->GetAsDictionary() && image_infos_json_sp->GetAsDictionary()->HasKey("images") && image_infos_json_sp->GetAsDictionary() ->GetValueForKey("images") ->GetAsArray() && image_infos_json_sp->GetAsDictionary() ->GetValueForKey("images") ->GetAsArray() ->GetSize() == image_infos_count) { bool return_value = false; if (JSONImageInformationIntoImageInfo(image_infos_json_sp, image_infos)) { UpdateSpecialBinariesFromNewImageInfos(image_infos); return_value = AddModulesUsingImageInfos(image_infos); } m_dyld_image_infos_stop_id = m_process->GetStopID(); return return_value; } if (!ReadImageInfos(image_infos_addr, image_infos_count, image_infos)) return false; UpdateImageInfosHeaderAndLoadCommands(image_infos, image_infos_count, false); bool return_value = AddModulesUsingImageInfos(image_infos); m_dyld_image_infos_stop_id = m_process->GetStopID(); return return_value; } bool DynamicLoaderMacOSXDYLD::RemoveModulesUsingImageInfosAddress( lldb::addr_t image_infos_addr, uint32_t image_infos_count) { ImageInfo::collection image_infos; Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); std::lock_guard guard(m_mutex); std::lock_guard baseclass_guard(GetMutex()); if (m_process->GetStopID() == m_dyld_image_infos_stop_id) return true; // First read in the image_infos for the removed modules, and their headers & // load commands. if (!ReadImageInfos(image_infos_addr, image_infos_count, image_infos)) { if (log) log->PutCString("Failed reading image infos array."); return false; } LLDB_LOGF(log, "Removing %d modules.", image_infos_count); ModuleList unloaded_module_list; for (uint32_t idx = 0; idx < image_infos.size(); ++idx) { if (log) { LLDB_LOGF(log, "Removing module at address=0x%16.16" PRIx64 ".", image_infos[idx].address); image_infos[idx].PutToLog(log); } // Remove this image_infos from the m_all_image_infos. We do the // comparison by address rather than by file spec because we can have many // modules with the same "file spec" in the case that they are modules // loaded from memory. // // Also copy over the uuid from the old entry to the removed entry so we // can use it to lookup the module in the module list. ImageInfo::collection::iterator pos, end = m_dyld_image_infos.end(); for (pos = m_dyld_image_infos.begin(); pos != end; pos++) { if (image_infos[idx].address == (*pos).address) { image_infos[idx].uuid = (*pos).uuid; // Add the module from this image_info to the "unloaded_module_list". // We'll remove them all at one go later on. ModuleSP unload_image_module_sp( FindTargetModuleForImageInfo(image_infos[idx], false, nullptr)); if (unload_image_module_sp.get()) { // When we unload, be sure to use the image info from the old list, // since that has sections correctly filled in. UnloadModuleSections(unload_image_module_sp.get(), *pos); unloaded_module_list.AppendIfNeeded(unload_image_module_sp); } else { if (log) { LLDB_LOGF(log, "Could not find module for unloading info entry:"); image_infos[idx].PutToLog(log); } } // Then remove it from the m_dyld_image_infos: m_dyld_image_infos.erase(pos); break; } } if (pos == end) { if (log) { LLDB_LOGF(log, "Could not find image_info entry for unloading image:"); image_infos[idx].PutToLog(log); } } } if (unloaded_module_list.GetSize() > 0) { if (log) { log->PutCString("Unloaded:"); unloaded_module_list.LogUUIDAndPaths( log, "DynamicLoaderMacOSXDYLD::ModulesDidUnload"); } m_process->GetTarget().GetImages().Remove(unloaded_module_list); } m_dyld_image_infos_stop_id = m_process->GetStopID(); return true; } bool DynamicLoaderMacOSXDYLD::ReadImageInfos( lldb::addr_t image_infos_addr, uint32_t image_infos_count, ImageInfo::collection &image_infos) { std::lock_guard baseclass_guard(GetMutex()); const ByteOrder endian = GetByteOrderFromMagic(m_dyld.header.magic); const uint32_t addr_size = m_dyld.GetAddressByteSize(); image_infos.resize(image_infos_count); const size_t count = image_infos.size() * 3 * addr_size; DataBufferHeap info_data(count, 0); Status error; const size_t bytes_read = m_process->ReadMemory( image_infos_addr, info_data.GetBytes(), info_data.GetByteSize(), error); if (bytes_read == count) { lldb::offset_t info_data_offset = 0; DataExtractor info_data_ref(info_data.GetBytes(), info_data.GetByteSize(), endian, addr_size); for (size_t i = 0; i < image_infos.size() && info_data_ref.ValidOffset(info_data_offset); i++) { image_infos[i].address = info_data_ref.GetPointer(&info_data_offset); lldb::addr_t path_addr = info_data_ref.GetPointer(&info_data_offset); image_infos[i].mod_date = info_data_ref.GetPointer(&info_data_offset); char raw_path[PATH_MAX]; m_process->ReadCStringFromMemory(path_addr, raw_path, sizeof(raw_path), error); // don't resolve the path if (error.Success()) { image_infos[i].file_spec.SetFile(raw_path, FileSpec::Style::native); } } return true; } else { return false; } } // If we have found where the "_dyld_all_image_infos" lives in memory, read the // current info from it, and then update all image load addresses (or lack // thereof). Only do this if this is the first time we're reading the dyld // infos. Return true if we actually read anything, and false otherwise. bool DynamicLoaderMacOSXDYLD::InitializeFromAllImageInfos() { Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); std::lock_guard guard(m_mutex); std::lock_guard baseclass_guard(GetMutex()); if (m_process->GetStopID() == m_dyld_image_infos_stop_id || m_dyld_image_infos.size() != 0) return false; if (ReadAllImageInfosStructure()) { // Nothing to load or unload? if (m_dyld_all_image_infos.dylib_info_count == 0) return true; if (m_dyld_all_image_infos.dylib_info_addr == 0) { // DYLD is updating the images now. So we should say we have no images, // and then we'll // figure it out when we hit the added breakpoint. return false; } else { if (!AddModulesUsingImageInfosAddress( m_dyld_all_image_infos.dylib_info_addr, m_dyld_all_image_infos.dylib_info_count)) { DEBUG_PRINTF("%s", "unable to read all data for all_dylib_infos."); m_dyld_image_infos.clear(); } } // Now we have one more bit of business. If there is a library left in the // images for our target that doesn't have a load address, then it must be // something that we were expecting to load (for instance we read a load // command for it) but it didn't in fact load - probably because // DYLD_*_PATH pointed to an equivalent version. We don't want it to stay // in the target's module list or it will confuse us, so unload it here. Target &target = m_process->GetTarget(); const ModuleList &target_modules = target.GetImages(); ModuleList not_loaded_modules; std::lock_guard guard(target_modules.GetMutex()); size_t num_modules = target_modules.GetSize(); for (size_t i = 0; i < num_modules; i++) { ModuleSP module_sp = target_modules.GetModuleAtIndexUnlocked(i); if (!module_sp->IsLoadedInTarget(&target)) { if (log) { StreamString s; module_sp->GetDescription(s.AsRawOstream()); LLDB_LOGF(log, "Unloading pre-run module: %s.", s.GetData()); } not_loaded_modules.Append(module_sp); } } if (not_loaded_modules.GetSize() != 0) { target.GetImages().Remove(not_loaded_modules); } return true; } else return false; } // Read a mach_header at ADDR into HEADER, and also fill in the load command // data into LOAD_COMMAND_DATA if it is non-NULL. // // Returns true if we succeed, false if we fail for any reason. bool DynamicLoaderMacOSXDYLD::ReadMachHeader(lldb::addr_t addr, llvm::MachO::mach_header *header, DataExtractor *load_command_data) { DataBufferHeap header_bytes(sizeof(llvm::MachO::mach_header), 0); Status error; size_t bytes_read = m_process->ReadMemory(addr, header_bytes.GetBytes(), header_bytes.GetByteSize(), error); if (bytes_read == sizeof(llvm::MachO::mach_header)) { lldb::offset_t offset = 0; ::memset(header, 0, sizeof(llvm::MachO::mach_header)); // Get the magic byte unswapped so we can figure out what we are dealing // with DataExtractor data(header_bytes.GetBytes(), header_bytes.GetByteSize(), endian::InlHostByteOrder(), 4); header->magic = data.GetU32(&offset); lldb::addr_t load_cmd_addr = addr; data.SetByteOrder( DynamicLoaderMacOSXDYLD::GetByteOrderFromMagic(header->magic)); switch (header->magic) { case llvm::MachO::MH_MAGIC: case llvm::MachO::MH_CIGAM: data.SetAddressByteSize(4); load_cmd_addr += sizeof(llvm::MachO::mach_header); break; case llvm::MachO::MH_MAGIC_64: case llvm::MachO::MH_CIGAM_64: data.SetAddressByteSize(8); load_cmd_addr += sizeof(llvm::MachO::mach_header_64); break; default: return false; } // Read the rest of dyld's mach header if (data.GetU32(&offset, &header->cputype, (sizeof(llvm::MachO::mach_header) / sizeof(uint32_t)) - 1)) { if (load_command_data == nullptr) return true; // We were able to read the mach_header and weren't asked // to read the load command bytes DataBufferSP load_cmd_data_sp(new DataBufferHeap(header->sizeofcmds, 0)); size_t load_cmd_bytes_read = m_process->ReadMemory(load_cmd_addr, load_cmd_data_sp->GetBytes(), load_cmd_data_sp->GetByteSize(), error); if (load_cmd_bytes_read == header->sizeofcmds) { // Set the load command data and also set the correct endian swap // settings and the correct address size load_command_data->SetData(load_cmd_data_sp, 0, header->sizeofcmds); load_command_data->SetByteOrder(data.GetByteOrder()); load_command_data->SetAddressByteSize(data.GetAddressByteSize()); return true; // We successfully read the mach_header and the load // command data } return false; // We weren't able to read the load command data } } return false; // We failed the read the mach_header } // Parse the load commands for an image uint32_t DynamicLoaderMacOSXDYLD::ParseLoadCommands(const DataExtractor &data, ImageInfo &dylib_info, FileSpec *lc_id_dylinker) { lldb::offset_t offset = 0; uint32_t cmd_idx; Segment segment; dylib_info.Clear(true); for (cmd_idx = 0; cmd_idx < dylib_info.header.ncmds; cmd_idx++) { // Clear out any load command specific data from DYLIB_INFO since we are // about to read it. if (data.ValidOffsetForDataOfSize(offset, sizeof(llvm::MachO::load_command))) { llvm::MachO::load_command load_cmd; lldb::offset_t load_cmd_offset = offset; load_cmd.cmd = data.GetU32(&offset); load_cmd.cmdsize = data.GetU32(&offset); switch (load_cmd.cmd) { case llvm::MachO::LC_SEGMENT: { segment.name.SetTrimmedCStringWithLength( (const char *)data.GetData(&offset, 16), 16); // We are putting 4 uint32_t values 4 uint64_t values so we have to use // multiple 32 bit gets below. segment.vmaddr = data.GetU32(&offset); segment.vmsize = data.GetU32(&offset); segment.fileoff = data.GetU32(&offset); segment.filesize = data.GetU32(&offset); // Extract maxprot, initprot, nsects and flags all at once data.GetU32(&offset, &segment.maxprot, 4); dylib_info.segments.push_back(segment); } break; case llvm::MachO::LC_SEGMENT_64: { segment.name.SetTrimmedCStringWithLength( (const char *)data.GetData(&offset, 16), 16); // Extract vmaddr, vmsize, fileoff, and filesize all at once data.GetU64(&offset, &segment.vmaddr, 4); // Extract maxprot, initprot, nsects and flags all at once data.GetU32(&offset, &segment.maxprot, 4); dylib_info.segments.push_back(segment); } break; case llvm::MachO::LC_ID_DYLINKER: if (lc_id_dylinker) { const lldb::offset_t name_offset = load_cmd_offset + data.GetU32(&offset); const char *path = data.PeekCStr(name_offset); lc_id_dylinker->SetFile(path, FileSpec::Style::native); FileSystem::Instance().Resolve(*lc_id_dylinker); } break; case llvm::MachO::LC_UUID: dylib_info.uuid = UUID::fromOptionalData(data.GetData(&offset, 16), 16); break; default: break; } // Set offset to be the beginning of the next load command. offset = load_cmd_offset + load_cmd.cmdsize; } } // All sections listed in the dyld image info structure will all either be // fixed up already, or they will all be off by a single slide amount that is // determined by finding the first segment that is at file offset zero which // also has bytes (a file size that is greater than zero) in the object file. // Determine the slide amount (if any) const size_t num_sections = dylib_info.segments.size(); for (size_t i = 0; i < num_sections; ++i) { // Iterate through the object file sections to find the first section that // starts of file offset zero and that has bytes in the file... if ((dylib_info.segments[i].fileoff == 0 && dylib_info.segments[i].filesize > 0) || (dylib_info.segments[i].name == "__TEXT")) { dylib_info.slide = dylib_info.address - dylib_info.segments[i].vmaddr; // We have found the slide amount, so we can exit this for loop. break; } } return cmd_idx; } // Read the mach_header and load commands for each image that the // _dyld_all_image_infos structure points to and cache the results. void DynamicLoaderMacOSXDYLD::UpdateImageInfosHeaderAndLoadCommands( ImageInfo::collection &image_infos, uint32_t infos_count, bool update_executable) { uint32_t exe_idx = UINT32_MAX; // Read any UUID values that we can get for (uint32_t i = 0; i < infos_count; i++) { if (!image_infos[i].UUIDValid()) { DataExtractor data; // Load command data if (!ReadMachHeader(image_infos[i].address, &image_infos[i].header, &data)) continue; ParseLoadCommands(data, image_infos[i], nullptr); if (image_infos[i].header.filetype == llvm::MachO::MH_EXECUTE) exe_idx = i; } } Target &target = m_process->GetTarget(); if (exe_idx < image_infos.size()) { const bool can_create = true; ModuleSP exe_module_sp(FindTargetModuleForImageInfo(image_infos[exe_idx], can_create, nullptr)); if (exe_module_sp) { UpdateImageLoadAddress(exe_module_sp.get(), image_infos[exe_idx]); if (exe_module_sp.get() != target.GetExecutableModulePointer()) { // Don't load dependent images since we are in dyld where we will know // and find out about all images that are loaded. Also when setting the // executable module, it will clear the targets module list, and if we // have an in memory dyld module, it will get removed from the list so // we will need to add it back after setting the executable module, so // we first try and see if we already have a weak pointer to the dyld // module, make it into a shared pointer, then add the executable, then // re-add it back to make sure it is always in the list. ModuleSP dyld_module_sp(GetDYLDModule()); m_process->GetTarget().SetExecutableModule(exe_module_sp, eLoadDependentsNo); if (dyld_module_sp) { if (target.GetImages().AppendIfNeeded(dyld_module_sp)) { std::lock_guard baseclass_guard(GetMutex()); // Also add it to the section list. UpdateImageLoadAddress(dyld_module_sp.get(), m_dyld); } } } } } } // Dump the _dyld_all_image_infos members and all current image infos that we // have parsed to the file handle provided. void DynamicLoaderMacOSXDYLD::PutToLog(Log *log) const { if (log == nullptr) return; std::lock_guard guard(m_mutex); std::lock_guard baseclass_guard(GetMutex()); LLDB_LOGF(log, "dyld_all_image_infos = { version=%d, count=%d, addr=0x%8.8" PRIx64 ", notify=0x%8.8" PRIx64 " }", m_dyld_all_image_infos.version, m_dyld_all_image_infos.dylib_info_count, (uint64_t)m_dyld_all_image_infos.dylib_info_addr, (uint64_t)m_dyld_all_image_infos.notification); size_t i; const size_t count = m_dyld_image_infos.size(); if (count > 0) { log->PutCString("Loaded:"); for (i = 0; i < count; i++) m_dyld_image_infos[i].PutToLog(log); } } bool DynamicLoaderMacOSXDYLD::SetNotificationBreakpoint() { DEBUG_PRINTF("DynamicLoaderMacOSXDYLD::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState())); if (m_break_id == LLDB_INVALID_BREAK_ID) { if (m_dyld_all_image_infos.notification != LLDB_INVALID_ADDRESS) { Address so_addr; // Set the notification breakpoint and install a breakpoint callback // function that will get called each time the breakpoint gets hit. We // will use this to track when shared libraries get loaded/unloaded. bool resolved = m_process->GetTarget().ResolveLoadAddress( m_dyld_all_image_infos.notification, so_addr); if (!resolved) { ModuleSP dyld_module_sp = GetDYLDModule(); if (dyld_module_sp) { std::lock_guard baseclass_guard(GetMutex()); UpdateImageLoadAddress(dyld_module_sp.get(), m_dyld); resolved = m_process->GetTarget().ResolveLoadAddress( m_dyld_all_image_infos.notification, so_addr); } } if (resolved) { Breakpoint *dyld_break = m_process->GetTarget().CreateBreakpoint(so_addr, true, false).get(); dyld_break->SetCallback(DynamicLoaderMacOSXDYLD::NotifyBreakpointHit, this, true); dyld_break->SetBreakpointKind("shared-library-event"); m_break_id = dyld_break->GetID(); } } } return m_break_id != LLDB_INVALID_BREAK_ID; } Status DynamicLoaderMacOSXDYLD::CanLoadImage() { Status error; // In order for us to tell if we can load a shared library we verify that the // dylib_info_addr isn't zero (which means no shared libraries have been set // yet, or dyld is currently mucking with the shared library list). if (ReadAllImageInfosStructure()) { // TODO: also check the _dyld_global_lock_held variable in // libSystem.B.dylib? // TODO: check the malloc lock? // TODO: check the objective C lock? if (m_dyld_all_image_infos.dylib_info_addr != 0) return error; // Success } error.SetErrorString("unsafe to load or unload shared libraries"); return error; } bool DynamicLoaderMacOSXDYLD::GetSharedCacheInformation( lldb::addr_t &base_address, UUID &uuid, LazyBool &using_shared_cache, LazyBool &private_shared_cache) { base_address = LLDB_INVALID_ADDRESS; uuid.Clear(); using_shared_cache = eLazyBoolCalculate; private_shared_cache = eLazyBoolCalculate; if (m_process) { addr_t all_image_infos = m_process->GetImageInfoAddress(); // The address returned by GetImageInfoAddress may be the address of dyld // (don't want) or it may be the address of the dyld_all_image_infos // structure (want). The first four bytes will be either the version field // (all_image_infos) or a Mach-O file magic constant. Version 13 and higher // of dyld_all_image_infos is required to get the sharedCacheUUID field. Status err; uint32_t version_or_magic = m_process->ReadUnsignedIntegerFromMemory(all_image_infos, 4, -1, err); if (version_or_magic != static_cast(-1) && version_or_magic != llvm::MachO::MH_MAGIC && version_or_magic != llvm::MachO::MH_CIGAM && version_or_magic != llvm::MachO::MH_MAGIC_64 && version_or_magic != llvm::MachO::MH_CIGAM_64 && version_or_magic >= 13) { addr_t sharedCacheUUID_address = LLDB_INVALID_ADDRESS; int wordsize = m_process->GetAddressByteSize(); if (wordsize == 8) { sharedCacheUUID_address = all_image_infos + 160; // sharedCacheUUID } if (wordsize == 4) { sharedCacheUUID_address = all_image_infos + 84; // sharedCacheUUID } if (sharedCacheUUID_address != LLDB_INVALID_ADDRESS) { uuid_t shared_cache_uuid; if (m_process->ReadMemory(sharedCacheUUID_address, shared_cache_uuid, sizeof(uuid_t), err) == sizeof(uuid_t)) { uuid = UUID::fromOptionalData(shared_cache_uuid, 16); if (uuid.IsValid()) { using_shared_cache = eLazyBoolYes; } } if (version_or_magic >= 15) { // The sharedCacheBaseAddress field is the next one in the // dyld_all_image_infos struct. addr_t sharedCacheBaseAddr_address = sharedCacheUUID_address + 16; Status error; base_address = m_process->ReadUnsignedIntegerFromMemory( sharedCacheBaseAddr_address, wordsize, LLDB_INVALID_ADDRESS, error); if (error.Fail()) base_address = LLDB_INVALID_ADDRESS; } return true; } // // add // NB: sharedCacheBaseAddress is the next field in dyld_all_image_infos // after // sharedCacheUUID -- that is, 16 bytes after it, if we wanted to fetch // it. } } return false; } void DynamicLoaderMacOSXDYLD::Initialize() { PluginManager::RegisterPlugin(GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance); } void DynamicLoaderMacOSXDYLD::Terminate() { PluginManager::UnregisterPlugin(CreateInstance); } lldb_private::ConstString DynamicLoaderMacOSXDYLD::GetPluginNameStatic() { static ConstString g_name("macosx-dyld"); return g_name; } const char *DynamicLoaderMacOSXDYLD::GetPluginDescriptionStatic() { return "Dynamic loader plug-in that watches for shared library loads/unloads " "in MacOSX user processes."; } // PluginInterface protocol lldb_private::ConstString DynamicLoaderMacOSXDYLD::GetPluginName() { return GetPluginNameStatic(); } uint32_t DynamicLoaderMacOSXDYLD::GetPluginVersion() { return 1; } uint32_t DynamicLoaderMacOSXDYLD::AddrByteSize() { std::lock_guard baseclass_guard(GetMutex()); switch (m_dyld.header.magic) { case llvm::MachO::MH_MAGIC: case llvm::MachO::MH_CIGAM: return 4; case llvm::MachO::MH_MAGIC_64: case llvm::MachO::MH_CIGAM_64: return 8; default: break; } return 0; } lldb::ByteOrder DynamicLoaderMacOSXDYLD::GetByteOrderFromMagic(uint32_t magic) { switch (magic) { case llvm::MachO::MH_MAGIC: case llvm::MachO::MH_MAGIC_64: return endian::InlHostByteOrder(); case llvm::MachO::MH_CIGAM: case llvm::MachO::MH_CIGAM_64: if (endian::InlHostByteOrder() == lldb::eByteOrderBig) return lldb::eByteOrderLittle; else return lldb::eByteOrderBig; default: break; } return lldb::eByteOrderInvalid; }