398 lines · cpp
1//===-- AppleGetItemInfoHandler.cpp ---------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "AppleGetItemInfoHandler.h"10 11#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"12#include "lldb/Core/Module.h"13#include "lldb/Core/Value.h"14#include "lldb/Expression/DiagnosticManager.h"15#include "lldb/Expression/FunctionCaller.h"16#include "lldb/Expression/UtilityFunction.h"17#include "lldb/Symbol/Symbol.h"18#include "lldb/Target/ExecutionContext.h"19#include "lldb/Target/Process.h"20#include "lldb/Target/Target.h"21#include "lldb/Target/Thread.h"22#include "lldb/Utility/ConstString.h"23#include "lldb/Utility/LLDBLog.h"24#include "lldb/Utility/Log.h"25#include "lldb/Utility/StreamString.h"26 27using namespace lldb;28using namespace lldb_private;29 30const char *AppleGetItemInfoHandler::g_get_item_info_function_name =31 "__lldb_backtrace_recording_get_item_info";32const char *AppleGetItemInfoHandler::g_get_item_info_function_code =33 " \n\34extern \"C\" \n\35{ \n\36 /* \n\37 * mach defines \n\38 */ \n\39 \n\40 typedef unsigned int uint32_t; \n\41 typedef unsigned long long uint64_t; \n\42 typedef uint32_t mach_port_t; \n\43 typedef mach_port_t vm_map_t; \n\44 typedef int kern_return_t; \n\45 typedef uint64_t mach_vm_address_t; \n\46 typedef uint64_t mach_vm_size_t; \n\47 \n\48 mach_port_t mach_task_self (); \n\49 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\50 \n\51 /* \n\52 * libBacktraceRecording defines \n\53 */ \n\54 \n\55 typedef uint32_t queue_list_scope_t; \n\56 typedef void *dispatch_queue_t; \n\57 typedef void *introspection_dispatch_queue_info_t; \n\58 typedef void *introspection_dispatch_item_info_ref; \n\59 \n\60 extern uint64_t __introspection_dispatch_queue_item_get_info (introspection_dispatch_item_info_ref item_info_ref, \n\61 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\62 uint64_t *returned_queues_buffer_size); \n\63 extern int printf(const char *format, ...); \n\64 \n\65 /* \n\66 * return type define \n\67 */ \n\68 \n\69 struct get_item_info_return_values \n\70 { \n\71 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\72 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\73 }; \n\74 \n\75 void __lldb_backtrace_recording_get_item_info \n\76 (struct get_item_info_return_values *return_buffer, \n\77 int debug, \n\78 uint64_t /* introspection_dispatch_item_info_ref item_info_ref */ item, \n\79 void *page_to_free, \n\80 uint64_t page_to_free_size) \n\81{ \n\82 if (debug) \n\83 printf (\"entering get_item_info with args return_buffer == %p, debug == %d, item == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, item, page_to_free, page_to_free_size); \n\84 if (page_to_free != 0) \n\85 { \n\86 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\87 } \n\88 \n\89 __introspection_dispatch_queue_item_get_info ((void*) item, \n\90 (void**)&return_buffer->item_info_buffer_ptr, \n\91 &return_buffer->item_info_buffer_size); \n\92} \n\93} \n\94";95 96AppleGetItemInfoHandler::AppleGetItemInfoHandler(Process *process)97 : m_process(process), m_get_item_info_impl_code(),98 m_get_item_info_function_mutex(),99 m_get_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS),100 m_get_item_info_retbuffer_mutex() {}101 102AppleGetItemInfoHandler::~AppleGetItemInfoHandler() = default;103 104void AppleGetItemInfoHandler::Detach() {105 106 if (m_process && m_process->IsAlive() &&107 m_get_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) {108 std::unique_lock<std::mutex> lock(m_get_item_info_retbuffer_mutex,109 std::defer_lock);110 (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer111 m_process->DeallocateMemory(m_get_item_info_return_buffer_addr);112 }113}114 115// Compile our __lldb_backtrace_recording_get_item_info() function (from the116// source above in g_get_item_info_function_code) if we don't find that117// function in the inferior already with USE_BUILTIN_FUNCTION defined. (e.g.118// this would be the case for testing.)119//120// Insert the __lldb_backtrace_recording_get_item_info into the inferior121// process if needed.122//123// Write the get_item_info_arglist into the inferior's memory space to prepare124// for the call.125//126// Returns the address of the arguments written down in the inferior process,127// which can be used to make the function call.128 129lldb::addr_t AppleGetItemInfoHandler::SetupGetItemInfoFunction(130 Thread &thread, ValueList &get_item_info_arglist) {131 ExecutionContext exe_ctx(thread.shared_from_this());132 DiagnosticManager diagnostics;133 Log *log = GetLog(LLDBLog::SystemRuntime);134 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;135 FunctionCaller *get_item_info_caller = nullptr;136 137 // Scope for mutex locker:138 {139 std::lock_guard<std::mutex> guard(m_get_item_info_function_mutex);140 141 // First stage is to make the UtilityFunction to hold our injected142 // function:143 144 if (!m_get_item_info_impl_code) {145 if (g_get_item_info_function_code != nullptr) {146 auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction(147 g_get_item_info_function_code, g_get_item_info_function_name,148 eLanguageTypeObjC, exe_ctx);149 if (!utility_fn_or_error) {150 LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(),151 "Failed to create utility function: {0}");152 }153 m_get_item_info_impl_code = std::move(*utility_fn_or_error);154 } else {155 LLDB_LOGF(log, "No get-item-info introspection code found.");156 return LLDB_INVALID_ADDRESS;157 }158 159 // Next make the runner function for our implementation utility function.160 auto type_system_or_err =161 thread.GetProcess()->GetTarget().GetScratchTypeSystemForLanguage(162 eLanguageTypeC);163 if (auto err = type_system_or_err.takeError()) {164 LLDB_LOG_ERROR(log, std::move(err),165 "Error inserting get-item-info function: {0}");166 return args_addr;167 }168 auto ts = *type_system_or_err;169 if (!ts)170 return args_addr;171 172 CompilerType get_item_info_return_type =173 ts->GetBasicTypeFromAST(eBasicTypeVoid)174 .GetPointerType();175 176 Status error;177 get_item_info_caller = m_get_item_info_impl_code->MakeFunctionCaller(178 get_item_info_return_type, get_item_info_arglist,179 thread.shared_from_this(), error);180 if (error.Fail() || get_item_info_caller == nullptr) {181 LLDB_LOGF(log, "Error inserting get-item-info function: \"%s\".",182 error.AsCString());183 return args_addr;184 }185 } else {186 // If it's already made, then we can just retrieve the caller:187 get_item_info_caller = m_get_item_info_impl_code->GetFunctionCaller();188 if (!get_item_info_caller) {189 LLDB_LOGF(log, "Failed to get get-item-info introspection caller.");190 m_get_item_info_impl_code.reset();191 return args_addr;192 }193 }194 }195 196 diagnostics.Clear();197 198 // Now write down the argument values for this particular call. This looks199 // like it might be a race condition if other threads were calling into here,200 // but actually it isn't because we allocate a new args structure for this201 // call by passing args_addr = LLDB_INVALID_ADDRESS...202 203 if (!get_item_info_caller->WriteFunctionArguments(204 exe_ctx, args_addr, get_item_info_arglist, diagnostics)) {205 if (log) {206 LLDB_LOGF(log, "Error writing get-item-info function arguments.");207 diagnostics.Dump(log);208 }209 210 return args_addr;211 }212 213 return args_addr;214}215 216AppleGetItemInfoHandler::GetItemInfoReturnInfo217AppleGetItemInfoHandler::GetItemInfo(Thread &thread, uint64_t item,218 addr_t page_to_free,219 uint64_t page_to_free_size,220 Status &error) {221 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);222 ProcessSP process_sp(thread.CalculateProcess());223 TargetSP target_sp(thread.CalculateTarget());224 TypeSystemClangSP scratch_ts_sp =225 ScratchTypeSystemClang::GetForTarget(*target_sp);226 Log *log = GetLog(LLDBLog::SystemRuntime);227 228 GetItemInfoReturnInfo return_value;229 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;230 return_value.item_buffer_size = 0;231 232 error.Clear();233 234 if (!thread.SafeToCallFunctions()) {235 LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64,236 thread.GetID());237 error =238 Status::FromErrorString("Not safe to call functions on this thread.");239 return return_value;240 }241 242 // Set up the arguments for a call to243 244 // struct get_item_info_return_values245 // {246 // uint64_t item_info_buffer_ptr; /* the address of the items buffer247 // from libBacktraceRecording */248 // uint64_t item_info_buffer_size; /* the size of the items buffer from249 // libBacktraceRecording */250 // };251 //252 // void __lldb_backtrace_recording_get_item_info253 // (struct254 // get_item_info_return_values255 // *return_buffer,256 // int debug,257 // uint64_t item,258 // void *page_to_free,259 // uint64_t page_to_free_size)260 261 // Where the return_buffer argument points to a 24 byte region of memory262 // already allocated by lldb in the inferior process.263 264 CompilerType clang_void_ptr_type =265 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();266 Value return_buffer_ptr_value;267 return_buffer_ptr_value.SetValueType(Value::ValueType::Scalar);268 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type);269 270 CompilerType clang_int_type = scratch_ts_sp->GetBasicType(eBasicTypeInt);271 Value debug_value;272 debug_value.SetValueType(Value::ValueType::Scalar);273 debug_value.SetCompilerType(clang_int_type);274 275 CompilerType clang_uint64_type =276 scratch_ts_sp->GetBasicType(eBasicTypeUnsignedLongLong);277 Value item_value;278 item_value.SetValueType(Value::ValueType::Scalar);279 item_value.SetCompilerType(clang_uint64_type);280 281 Value page_to_free_value;282 page_to_free_value.SetValueType(Value::ValueType::Scalar);283 page_to_free_value.SetCompilerType(clang_void_ptr_type);284 285 Value page_to_free_size_value;286 page_to_free_size_value.SetValueType(Value::ValueType::Scalar);287 page_to_free_size_value.SetCompilerType(clang_uint64_type);288 289 std::lock_guard<std::mutex> guard(m_get_item_info_retbuffer_mutex);290 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) {291 addr_t bufaddr = process_sp->AllocateMemory(292 32, ePermissionsReadable | ePermissionsWritable, error);293 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) {294 LLDB_LOGF(log, "Failed to allocate memory for return buffer for get "295 "current queues func call");296 return return_value;297 }298 m_get_item_info_return_buffer_addr = bufaddr;299 }300 301 ValueList argument_values;302 303 return_buffer_ptr_value.GetScalar() = m_get_item_info_return_buffer_addr;304 argument_values.PushValue(return_buffer_ptr_value);305 306 debug_value.GetScalar() = 0;307 argument_values.PushValue(debug_value);308 309 item_value.GetScalar() = item;310 argument_values.PushValue(item_value);311 312 if (page_to_free != LLDB_INVALID_ADDRESS)313 page_to_free_value.GetScalar() = page_to_free;314 else315 page_to_free_value.GetScalar() = 0;316 argument_values.PushValue(page_to_free_value);317 318 page_to_free_size_value.GetScalar() = page_to_free_size;319 argument_values.PushValue(page_to_free_size_value);320 321 addr_t args_addr = SetupGetItemInfoFunction(thread, argument_values);322 323 DiagnosticManager diagnostics;324 ExecutionContext exe_ctx;325 EvaluateExpressionOptions options;326 options.SetUnwindOnError(true);327 options.SetIgnoreBreakpoints(true);328 options.SetStopOthers(true);329#if __has_feature(address_sanitizer)330 options.SetTimeout(process_sp->GetUtilityExpressionTimeout());331#else332 options.SetTimeout(std::chrono::milliseconds(500));333#endif334 options.SetTimeout(process_sp->GetUtilityExpressionTimeout());335 options.SetTryAllThreads(false);336 options.SetIsForUtilityExpr(true);337 thread.CalculateExecutionContext(exe_ctx);338 339 if (!m_get_item_info_impl_code) {340 error =341 Status::FromErrorString("Unable to compile function to call "342 "__introspection_dispatch_queue_item_get_info");343 return return_value;344 }345 346 ExpressionResults func_call_ret;347 Value results;348 FunctionCaller *func_caller = m_get_item_info_impl_code->GetFunctionCaller();349 if (!func_caller) {350 LLDB_LOGF(log, "Could not retrieve function caller for "351 "__introspection_dispatch_queue_item_get_info.");352 error = Status::FromErrorString(353 "Could not retrieve function caller for "354 "__introspection_dispatch_queue_item_get_info.");355 return return_value;356 }357 358 func_call_ret = func_caller->ExecuteFunction(exe_ctx, &args_addr, options,359 diagnostics, results);360 if (func_call_ret != eExpressionCompleted || !error.Success()) {361 LLDB_LOGF(log,362 "Unable to call "363 "__introspection_dispatch_queue_item_get_info(), got "364 "ExpressionResults %d, error contains %s",365 func_call_ret, error.AsCString(""));366 error = Status::FromErrorString(367 "Unable to call "368 "__introspection_dispatch_queue_get_item_info() for "369 "list of queues");370 return return_value;371 }372 373 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory(374 m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error);375 if (!error.Success() ||376 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) {377 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;378 return return_value;379 }380 381 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory(382 m_get_item_info_return_buffer_addr + 8, 8, 0, error);383 384 if (!error.Success()) {385 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;386 return return_value;387 }388 LLDB_LOGF(log,389 "AppleGetItemInfoHandler called "390 "__introspection_dispatch_queue_item_get_info (page_to_free == "391 "0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64392 ", size %" PRId64,393 page_to_free, page_to_free_size, return_value.item_buffer_ptr,394 return_value.item_buffer_size);395 396 return return_value;397}398