402 lines · cpp
1//===-- AppleGetThreadItemInfoHandler.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 "AppleGetThreadItemInfoHandler.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/Expression.h"16#include "lldb/Expression/FunctionCaller.h"17#include "lldb/Expression/UtilityFunction.h"18#include "lldb/Symbol/Symbol.h"19#include "lldb/Target/ExecutionContext.h"20#include "lldb/Target/Process.h"21#include "lldb/Target/StackFrame.h"22#include "lldb/Target/Target.h"23#include "lldb/Target/Thread.h"24#include "lldb/Utility/ConstString.h"25#include "lldb/Utility/LLDBLog.h"26#include "lldb/Utility/Log.h"27#include "lldb/Utility/StreamString.h"28#include "lldb/lldb-private.h"29 30using namespace lldb;31using namespace lldb_private;32 33const char34 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_name =35 "__lldb_backtrace_recording_get_thread_item_info";36const char37 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_code =38 " \n\39extern \"C\" \n\40{ \n\41 /* \n\42 * mach defines \n\43 */ \n\44 \n\45 typedef unsigned int uint32_t; \n\46 typedef unsigned long long uint64_t; \n\47 typedef uint32_t mach_port_t; \n\48 typedef mach_port_t vm_map_t; \n\49 typedef int kern_return_t; \n\50 typedef uint64_t mach_vm_address_t; \n\51 typedef uint64_t mach_vm_size_t; \n\52 \n\53 mach_port_t mach_task_self (); \n\54 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\55 \n\56 typedef void *pthread_t; \n\57 extern int printf(const char *format, ...); \n\58 extern pthread_t pthread_self(void); \n\59 \n\60 /* \n\61 * libBacktraceRecording defines \n\62 */ \n\63 \n\64 typedef uint32_t queue_list_scope_t; \n\65 typedef void *dispatch_queue_t; \n\66 typedef void *introspection_dispatch_queue_info_t; \n\67 typedef void *introspection_dispatch_item_info_ref; \n\68 \n\69 extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\70 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\71 uint64_t *returned_queues_buffer_size); \n\72 \n\73 /* \n\74 * return type define \n\75 */ \n\76 \n\77 struct get_thread_item_info_return_values \n\78 { \n\79 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\80 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\81 }; \n\82 \n\83 void __lldb_backtrace_recording_get_thread_item_info \n\84 (struct get_thread_item_info_return_values *return_buffer, \n\85 int debug, \n\86 uint64_t thread_id, \n\87 void *page_to_free, \n\88 uint64_t page_to_free_size) \n\89{ \n\90 void *pthread_id = pthread_self (); \n\91 if (debug) \n\92 printf (\"entering get_thread_item_info with args return_buffer == %p, debug == %d, thread id == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, (uint64_t) thread_id, page_to_free, page_to_free_size); \n\93 if (page_to_free != 0) \n\94 { \n\95 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\96 } \n\97 \n\98 __introspection_dispatch_thread_get_item_info (thread_id, \n\99 (void**)&return_buffer->item_info_buffer_ptr, \n\100 &return_buffer->item_info_buffer_size); \n\101} \n\102} \n\103";104 105AppleGetThreadItemInfoHandler::AppleGetThreadItemInfoHandler(Process *process)106 : m_process(process), m_get_thread_item_info_impl_code(),107 m_get_thread_item_info_function_mutex(),108 m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS),109 m_get_thread_item_info_retbuffer_mutex() {}110 111AppleGetThreadItemInfoHandler::~AppleGetThreadItemInfoHandler() = default;112 113void AppleGetThreadItemInfoHandler::Detach() {114 115 if (m_process && m_process->IsAlive() &&116 m_get_thread_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) {117 std::unique_lock<std::mutex> lock(m_get_thread_item_info_retbuffer_mutex,118 std::defer_lock);119 (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer120 m_process->DeallocateMemory(m_get_thread_item_info_return_buffer_addr);121 }122}123 124// Compile our __lldb_backtrace_recording_get_thread_item_info() function (from125// the source above in g_get_thread_item_info_function_code) if we don't find126// that function in the inferior already with USE_BUILTIN_FUNCTION defined.127// (e.g. this would be the case for testing.)128//129// Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior130// process if needed.131//132// Write the get_thread_item_info_arglist into the inferior's memory space to133// prepare for the call.134//135// Returns the address of the arguments written down in the inferior process,136// which can be used to make the function call.137 138lldb::addr_t AppleGetThreadItemInfoHandler::SetupGetThreadItemInfoFunction(139 Thread &thread, ValueList &get_thread_item_info_arglist) {140 ThreadSP thread_sp(thread.shared_from_this());141 ExecutionContext exe_ctx(thread_sp);142 Address impl_code_address;143 DiagnosticManager diagnostics;144 Log *log = GetLog(LLDBLog::SystemRuntime);145 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;146 FunctionCaller *get_thread_item_info_caller = nullptr;147 148 // Scope for mutex locker:149 {150 std::lock_guard<std::mutex> guard(m_get_thread_item_info_function_mutex);151 152 // First stage is to make the ClangUtility to hold our injected function:153 154 if (!m_get_thread_item_info_impl_code) {155 Status error;156 if (g_get_thread_item_info_function_code != nullptr) {157 auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction(158 g_get_thread_item_info_function_code,159 g_get_thread_item_info_function_name, eLanguageTypeC, exe_ctx);160 if (!utility_fn_or_error) {161 LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(),162 "Failed to get UtilityFunction for "163 "get-thread-item-info introspection: {0}.");164 return args_addr;165 }166 m_get_thread_item_info_impl_code = std::move(*utility_fn_or_error);167 } else {168 LLDB_LOGF(log, "No get-thread-item-info introspection code found.");169 return LLDB_INVALID_ADDRESS;170 }171 172 // Also make the FunctionCaller for this UtilityFunction:173 174 TypeSystemClangSP scratch_ts_sp = ScratchTypeSystemClang::GetForTarget(175 thread.GetProcess()->GetTarget());176 CompilerType get_thread_item_info_return_type =177 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();178 179 get_thread_item_info_caller =180 m_get_thread_item_info_impl_code->MakeFunctionCaller(181 get_thread_item_info_return_type, get_thread_item_info_arglist,182 thread_sp, error);183 if (error.Fail() || get_thread_item_info_caller == nullptr) {184 LLDB_LOGF(log,185 "Failed to install get-thread-item-info introspection "186 "caller: %s.",187 error.AsCString());188 m_get_thread_item_info_impl_code.reset();189 return args_addr;190 }191 192 } else {193 get_thread_item_info_caller =194 m_get_thread_item_info_impl_code->GetFunctionCaller();195 }196 }197 198 diagnostics.Clear();199 200 // Now write down the argument values for this particular call. This looks201 // like it might be a race condition if other threads were calling into here,202 // but actually it isn't because we allocate a new args structure for this203 // call by passing args_addr = LLDB_INVALID_ADDRESS...204 205 if (!get_thread_item_info_caller->WriteFunctionArguments(206 exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) {207 if (log) {208 LLDB_LOGF(log, "Error writing get-thread-item-info function arguments");209 diagnostics.Dump(log);210 }211 return args_addr;212 }213 214 return args_addr;215}216 217AppleGetThreadItemInfoHandler::GetThreadItemInfoReturnInfo218AppleGetThreadItemInfoHandler::GetThreadItemInfo(Thread &thread,219 lldb::tid_t thread_id,220 addr_t page_to_free,221 uint64_t page_to_free_size,222 Status &error) {223 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);224 ProcessSP process_sp(thread.CalculateProcess());225 TargetSP target_sp(thread.CalculateTarget());226 TypeSystemClangSP scratch_ts_sp =227 ScratchTypeSystemClang::GetForTarget(*target_sp);228 Log *log = GetLog(LLDBLog::SystemRuntime);229 230 GetThreadItemInfoReturnInfo return_value;231 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;232 return_value.item_buffer_size = 0;233 234 error.Clear();235 236 if (!thread.SafeToCallFunctions()) {237 LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64,238 thread.GetID());239 error =240 Status::FromErrorString("Not safe to call functions on this thread.");241 return return_value;242 }243 244 // Set up the arguments for a call to245 246 // struct get_thread_item_info_return_values {247 // uint64_t item_info_buffer_ptr; /* the address of the items buffer248 // from libBacktraceRecording */249 // uint64_t item_info_buffer_size; /* the size of the items buffer from250 // libBacktraceRecording */251 // };252 //253 // void __lldb_backtrace_recording_get_thread_item_info254 // (struct255 // get_thread_item_info_return_values256 // *return_buffer,257 // int debug,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 thread_id_value;278 thread_id_value.SetValueType(Value::ValueType::Scalar);279 thread_id_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_thread_item_info_retbuffer_mutex);290 if (m_get_thread_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_thread_item_info_return_buffer_addr = bufaddr;299 }300 301 ValueList argument_values;302 303 return_buffer_ptr_value.GetScalar() =304 m_get_thread_item_info_return_buffer_addr;305 argument_values.PushValue(return_buffer_ptr_value);306 307 debug_value.GetScalar() = 0;308 argument_values.PushValue(debug_value);309 310 thread_id_value.GetScalar() = thread_id;311 argument_values.PushValue(thread_id_value);312 313 if (page_to_free != LLDB_INVALID_ADDRESS)314 page_to_free_value.GetScalar() = page_to_free;315 else316 page_to_free_value.GetScalar() = 0;317 argument_values.PushValue(page_to_free_value);318 319 page_to_free_size_value.GetScalar() = page_to_free_size;320 argument_values.PushValue(page_to_free_size_value);321 322 addr_t args_addr = SetupGetThreadItemInfoFunction(thread, argument_values);323 324 DiagnosticManager diagnostics;325 ExecutionContext exe_ctx;326 EvaluateExpressionOptions options;327 FunctionCaller *get_thread_item_info_caller = nullptr;328 329 options.SetUnwindOnError(true);330 options.SetIgnoreBreakpoints(true);331 options.SetStopOthers(true);332#if __has_feature(address_sanitizer)333 options.SetTimeout(process_sp->GetUtilityExpressionTimeout());334#else335 options.SetTimeout(std::chrono::milliseconds(500));336#endif337 options.SetTryAllThreads(false);338 options.SetIsForUtilityExpr(true);339 thread.CalculateExecutionContext(exe_ctx);340 341 if (!m_get_thread_item_info_impl_code) {342 error = Status::FromErrorString(343 "Unable to compile function to call "344 "__introspection_dispatch_thread_get_item_info");345 return return_value;346 }347 348 get_thread_item_info_caller =349 m_get_thread_item_info_impl_code->GetFunctionCaller();350 351 if (!get_thread_item_info_caller) {352 error = Status::FromErrorString(353 "Unable to compile function caller for "354 "__introspection_dispatch_thread_get_item_info");355 return return_value;356 }357 358 ExpressionResults func_call_ret;359 Value results;360 func_call_ret = get_thread_item_info_caller->ExecuteFunction(361 exe_ctx, &args_addr, options, diagnostics, results);362 if (func_call_ret != eExpressionCompleted || !error.Success()) {363 LLDB_LOGF(log,364 "Unable to call "365 "__introspection_dispatch_thread_get_item_info(), got "366 "ExpressionResults %d, error contains %s",367 func_call_ret, error.AsCString(""));368 error = Status::FromErrorString(369 "Unable to call "370 "__introspection_dispatch_thread_get_item_info() for "371 "list of queues");372 return return_value;373 }374 375 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory(376 m_get_thread_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS,377 error);378 if (!error.Success() ||379 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) {380 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;381 return return_value;382 }383 384 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory(385 m_get_thread_item_info_return_buffer_addr + 8, 8, 0, error);386 387 if (!error.Success()) {388 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS;389 return return_value;390 }391 392 LLDB_LOGF(log,393 "AppleGetThreadItemInfoHandler called "394 "__introspection_dispatch_thread_get_item_info (page_to_free "395 "== 0x%" PRIx64 ", size = %" PRId64396 "), returned page is at 0x%" PRIx64 ", size %" PRId64,397 page_to_free, page_to_free_size, return_value.item_buffer_ptr,398 return_value.item_buffer_size);399 400 return return_value;401}402