1 //===-- AppleGetItemInfoHandler.cpp -------------------------------*- C++ 2 //-*-===// 3 // 4 // The LLVM Compiler Infrastructure 5 // 6 // This file is distributed under the University of Illinois Open Source 7 // License. See LICENSE.TXT for details. 8 // 9 //===----------------------------------------------------------------------===// 10 11 #include "AppleGetItemInfoHandler.h" 12 13 // C Includes 14 // C++ Includes 15 // Other libraries and framework includes 16 // Project includes 17 18 #include "lldb/Core/Module.h" 19 #include "lldb/Core/Value.h" 20 #include "lldb/Expression/DiagnosticManager.h" 21 #include "lldb/Expression/FunctionCaller.h" 22 #include "lldb/Expression/UtilityFunction.h" 23 #include "lldb/Symbol/ClangASTContext.h" 24 #include "lldb/Symbol/Symbol.h" 25 #include "lldb/Target/ExecutionContext.h" 26 #include "lldb/Target/Process.h" 27 #include "lldb/Target/Target.h" 28 #include "lldb/Target/Thread.h" 29 #include "lldb/Utility/ConstString.h" 30 #include "lldb/Utility/Log.h" 31 #include "lldb/Utility/StreamString.h" 32 33 using namespace lldb; 34 using namespace lldb_private; 35 36 const char *AppleGetItemInfoHandler::g_get_item_info_function_name = 37 "__lldb_backtrace_recording_get_item_info"; 38 const char *AppleGetItemInfoHandler::g_get_item_info_function_code = 39 " \n\ 40 extern \"C\" \n\ 41 { \n\ 42 /* \n\ 43 * mach defines \n\ 44 */ \n\ 45 \n\ 46 typedef unsigned int uint32_t; \n\ 47 typedef unsigned long long uint64_t; \n\ 48 typedef uint32_t mach_port_t; \n\ 49 typedef mach_port_t vm_map_t; \n\ 50 typedef int kern_return_t; \n\ 51 typedef uint64_t mach_vm_address_t; \n\ 52 typedef uint64_t mach_vm_size_t; \n\ 53 \n\ 54 mach_port_t mach_task_self (); \n\ 55 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 56 \n\ 57 /* \n\ 58 * libBacktraceRecording defines \n\ 59 */ \n\ 60 \n\ 61 typedef uint32_t queue_list_scope_t; \n\ 62 typedef void *dispatch_queue_t; \n\ 63 typedef void *introspection_dispatch_queue_info_t; \n\ 64 typedef void *introspection_dispatch_item_info_ref; \n\ 65 \n\ 66 extern uint64_t __introspection_dispatch_queue_item_get_info (introspection_dispatch_item_info_ref item_info_ref, \n\ 67 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 68 uint64_t *returned_queues_buffer_size); \n\ 69 extern int printf(const char *format, ...); \n\ 70 \n\ 71 /* \n\ 72 * return type define \n\ 73 */ \n\ 74 \n\ 75 struct get_item_info_return_values \n\ 76 { \n\ 77 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 78 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 79 }; \n\ 80 \n\ 81 void __lldb_backtrace_recording_get_item_info \n\ 82 (struct get_item_info_return_values *return_buffer, \n\ 83 int debug, \n\ 84 uint64_t /* introspection_dispatch_item_info_ref item_info_ref */ item, \n\ 85 void *page_to_free, \n\ 86 uint64_t page_to_free_size) \n\ 87 { \n\ 88 if (debug) \n\ 89 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\ 90 if (page_to_free != 0) \n\ 91 { \n\ 92 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 93 } \n\ 94 \n\ 95 __introspection_dispatch_queue_item_get_info ((void*) item, \n\ 96 (void**)&return_buffer->item_info_buffer_ptr, \n\ 97 &return_buffer->item_info_buffer_size); \n\ 98 } \n\ 99 } \n\ 100 "; 101 102 AppleGetItemInfoHandler::AppleGetItemInfoHandler(Process *process) 103 : m_process(process), m_get_item_info_impl_code(), 104 m_get_item_info_function_mutex(), 105 m_get_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS), 106 m_get_item_info_retbuffer_mutex() {} 107 108 AppleGetItemInfoHandler::~AppleGetItemInfoHandler() {} 109 110 void AppleGetItemInfoHandler::Detach() { 111 112 if (m_process && m_process->IsAlive() && 113 m_get_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) { 114 std::unique_lock<std::mutex> lock(m_get_item_info_retbuffer_mutex, 115 std::defer_lock); 116 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 117 m_process->DeallocateMemory(m_get_item_info_return_buffer_addr); 118 } 119 } 120 121 // Compile our __lldb_backtrace_recording_get_item_info() function (from the 122 // source above in g_get_item_info_function_code) if we don't find that 123 // function in the inferior already with USE_BUILTIN_FUNCTION defined. (e.g. 124 // this would be the case for testing.) 125 // 126 // Insert the __lldb_backtrace_recording_get_item_info into the inferior 127 // process if needed. 128 // 129 // Write the get_item_info_arglist into the inferior's memory space to prepare 130 // for the call. 131 // 132 // Returns the address of the arguments written down in the inferior process, 133 // which can be used to make the function call. 134 135 lldb::addr_t AppleGetItemInfoHandler::SetupGetItemInfoFunction( 136 Thread &thread, ValueList &get_item_info_arglist) { 137 ExecutionContext exe_ctx(thread.shared_from_this()); 138 DiagnosticManager diagnostics; 139 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 140 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 141 FunctionCaller *get_item_info_caller = nullptr; 142 143 // Scope for mutex locker: 144 { 145 std::lock_guard<std::mutex> guard(m_get_item_info_function_mutex); 146 147 // First stage is to make the UtilityFunction to hold our injected 148 // function: 149 150 if (!m_get_item_info_impl_code.get()) { 151 if (g_get_item_info_function_code != NULL) { 152 Status error; 153 m_get_item_info_impl_code.reset( 154 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 155 g_get_item_info_function_code, eLanguageTypeObjC, 156 g_get_item_info_function_name, error)); 157 if (error.Fail()) { 158 if (log) 159 log->Printf("Failed to get utility function: %s.", 160 error.AsCString()); 161 return args_addr; 162 } 163 164 if (!m_get_item_info_impl_code->Install(diagnostics, exe_ctx)) { 165 if (log) { 166 log->Printf("Failed to install get-item-info introspection."); 167 diagnostics.Dump(log); 168 } 169 m_get_item_info_impl_code.reset(); 170 return args_addr; 171 } 172 } else { 173 if (log) 174 log->Printf("No get-item-info introspection code found."); 175 return LLDB_INVALID_ADDRESS; 176 } 177 178 // Next make the runner function for our implementation utility function. 179 Status error; 180 181 TypeSystem *type_system = 182 thread.GetProcess()->GetTarget().GetScratchTypeSystemForLanguage( 183 nullptr, eLanguageTypeC); 184 CompilerType get_item_info_return_type = 185 type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType(); 186 187 get_item_info_caller = m_get_item_info_impl_code->MakeFunctionCaller( 188 get_item_info_return_type, get_item_info_arglist, 189 thread.shared_from_this(), error); 190 if (error.Fail() || get_item_info_caller == nullptr) { 191 if (log) 192 log->Printf("Error Inserting get-item-info function: \"%s\".", 193 error.AsCString()); 194 return args_addr; 195 } 196 } else { 197 // If it's already made, then we can just retrieve the caller: 198 get_item_info_caller = m_get_item_info_impl_code->GetFunctionCaller(); 199 if (!get_item_info_caller) { 200 if (log) 201 log->Printf("Failed to get get-item-info introspection caller."); 202 m_get_item_info_impl_code.reset(); 203 return args_addr; 204 } 205 } 206 } 207 208 diagnostics.Clear(); 209 210 // Now write down the argument values for this particular call. This looks 211 // like it might be a race condition if other threads were calling into here, 212 // but actually it isn't because we allocate a new args structure for this 213 // call by passing args_addr = LLDB_INVALID_ADDRESS... 214 215 if (!get_item_info_caller->WriteFunctionArguments( 216 exe_ctx, args_addr, get_item_info_arglist, diagnostics)) { 217 if (log) { 218 log->Printf("Error writing get-item-info function arguments."); 219 diagnostics.Dump(log); 220 } 221 222 return args_addr; 223 } 224 225 return args_addr; 226 } 227 228 AppleGetItemInfoHandler::GetItemInfoReturnInfo 229 AppleGetItemInfoHandler::GetItemInfo(Thread &thread, uint64_t item, 230 addr_t page_to_free, 231 uint64_t page_to_free_size, 232 Status &error) { 233 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 234 ProcessSP process_sp(thread.CalculateProcess()); 235 TargetSP target_sp(thread.CalculateTarget()); 236 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 237 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 238 239 GetItemInfoReturnInfo return_value; 240 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 241 return_value.item_buffer_size = 0; 242 243 error.Clear(); 244 245 if (thread.SafeToCallFunctions() == false) { 246 if (log) 247 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 248 thread.GetID()); 249 error.SetErrorString("Not safe to call functions on this thread."); 250 return return_value; 251 } 252 253 // Set up the arguments for a call to 254 255 // struct get_item_info_return_values 256 // { 257 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 258 // from libBacktraceRecording */ 259 // uint64_t item_info_buffer_size; /* the size of the items buffer from 260 // libBacktraceRecording */ 261 // }; 262 // 263 // void __lldb_backtrace_recording_get_item_info 264 // (struct 265 // get_item_info_return_values 266 // *return_buffer, 267 // int debug, 268 // uint64_t item, 269 // void *page_to_free, 270 // uint64_t page_to_free_size) 271 272 // Where the return_buffer argument points to a 24 byte region of memory 273 // already allocated by lldb in the inferior process. 274 275 CompilerType clang_void_ptr_type = 276 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 277 Value return_buffer_ptr_value; 278 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 279 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 280 281 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 282 Value debug_value; 283 debug_value.SetValueType(Value::eValueTypeScalar); 284 debug_value.SetCompilerType(clang_int_type); 285 286 CompilerType clang_uint64_type = 287 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 288 Value item_value; 289 item_value.SetValueType(Value::eValueTypeScalar); 290 item_value.SetCompilerType(clang_uint64_type); 291 292 Value page_to_free_value; 293 page_to_free_value.SetValueType(Value::eValueTypeScalar); 294 page_to_free_value.SetCompilerType(clang_void_ptr_type); 295 296 Value page_to_free_size_value; 297 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 298 page_to_free_size_value.SetCompilerType(clang_uint64_type); 299 300 std::lock_guard<std::mutex> guard(m_get_item_info_retbuffer_mutex); 301 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 302 addr_t bufaddr = process_sp->AllocateMemory( 303 32, ePermissionsReadable | ePermissionsWritable, error); 304 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 305 if (log) 306 log->Printf("Failed to allocate memory for return buffer for get " 307 "current queues func call"); 308 return return_value; 309 } 310 m_get_item_info_return_buffer_addr = bufaddr; 311 } 312 313 ValueList argument_values; 314 315 return_buffer_ptr_value.GetScalar() = m_get_item_info_return_buffer_addr; 316 argument_values.PushValue(return_buffer_ptr_value); 317 318 debug_value.GetScalar() = 0; 319 argument_values.PushValue(debug_value); 320 321 item_value.GetScalar() = item; 322 argument_values.PushValue(item_value); 323 324 if (page_to_free != LLDB_INVALID_ADDRESS) 325 page_to_free_value.GetScalar() = page_to_free; 326 else 327 page_to_free_value.GetScalar() = 0; 328 argument_values.PushValue(page_to_free_value); 329 330 page_to_free_size_value.GetScalar() = page_to_free_size; 331 argument_values.PushValue(page_to_free_size_value); 332 333 addr_t args_addr = SetupGetItemInfoFunction(thread, argument_values); 334 335 DiagnosticManager diagnostics; 336 ExecutionContext exe_ctx; 337 EvaluateExpressionOptions options; 338 options.SetUnwindOnError(true); 339 options.SetIgnoreBreakpoints(true); 340 options.SetStopOthers(true); 341 options.SetTimeout(std::chrono::milliseconds(500)); 342 options.SetTryAllThreads(false); 343 options.SetIsForUtilityExpr(true); 344 thread.CalculateExecutionContext(exe_ctx); 345 346 if (!m_get_item_info_impl_code) { 347 error.SetErrorString("Unable to compile function to call " 348 "__introspection_dispatch_queue_item_get_info"); 349 return return_value; 350 } 351 352 ExpressionResults func_call_ret; 353 Value results; 354 FunctionCaller *func_caller = m_get_item_info_impl_code->GetFunctionCaller(); 355 if (!func_caller) { 356 if (log) 357 log->Printf("Could not retrieve function caller for " 358 "__introspection_dispatch_queue_item_get_info."); 359 error.SetErrorString("Could not retrieve function caller for " 360 "__introspection_dispatch_queue_item_get_info."); 361 return return_value; 362 } 363 364 func_call_ret = func_caller->ExecuteFunction(exe_ctx, &args_addr, options, 365 diagnostics, results); 366 if (func_call_ret != eExpressionCompleted || !error.Success()) { 367 if (log) 368 log->Printf("Unable to call " 369 "__introspection_dispatch_queue_item_get_info(), got " 370 "ExpressionResults %d, error contains %s", 371 func_call_ret, error.AsCString("")); 372 error.SetErrorString("Unable to call " 373 "__introspection_dispatch_queue_get_item_info() for " 374 "list of queues"); 375 return return_value; 376 } 377 378 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 379 m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 380 if (!error.Success() || 381 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { 382 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 383 return return_value; 384 } 385 386 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 387 m_get_item_info_return_buffer_addr + 8, 8, 0, error); 388 389 if (!error.Success()) { 390 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 391 return return_value; 392 } 393 if (log) 394 log->Printf("AppleGetItemInfoHandler called " 395 "__introspection_dispatch_queue_item_get_info (page_to_free == " 396 "0x%" PRIx64 ", size = %" PRId64 397 "), returned page is at 0x%" PRIx64 ", size %" PRId64, 398 page_to_free, page_to_free_size, return_value.item_buffer_ptr, 399 return_value.item_buffer_size); 400 401 return return_value; 402 } 403