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/ConstString.h" 19 #include "lldb/Core/Log.h" 20 #include "lldb/Core/Module.h" 21 #include "lldb/Core/StreamString.h" 22 #include "lldb/Core/Value.h" 23 #include "lldb/Expression/DiagnosticManager.h" 24 #include "lldb/Expression/FunctionCaller.h" 25 #include "lldb/Expression/UtilityFunction.h" 26 #include "lldb/Symbol/ClangASTContext.h" 27 #include "lldb/Symbol/Symbol.h" 28 #include "lldb/Target/ExecutionContext.h" 29 #include "lldb/Target/Process.h" 30 #include "lldb/Target/Target.h" 31 #include "lldb/Target/Thread.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 function 123 // in the inferior 124 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for 125 // testing.) 126 // 127 // Insert the __lldb_backtrace_recording_get_item_info into the inferior process 128 // if needed. 129 // 130 // Write the get_item_info_arglist into the inferior's memory space to prepare 131 // for the call. 132 // 133 // Returns the address of the arguments written down in the inferior process, 134 // which can be used to 135 // make the function call. 136 137 lldb::addr_t AppleGetItemInfoHandler::SetupGetItemInfoFunction( 138 Thread &thread, ValueList &get_item_info_arglist) { 139 ExecutionContext exe_ctx(thread.shared_from_this()); 140 DiagnosticManager diagnostics; 141 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 142 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 143 FunctionCaller *get_item_info_caller = nullptr; 144 145 // Scope for mutex locker: 146 { 147 std::lock_guard<std::mutex> guard(m_get_item_info_function_mutex); 148 149 // First stage is to make the UtilityFunction to hold our injected function: 150 151 if (!m_get_item_info_impl_code.get()) { 152 if (g_get_item_info_function_code != NULL) { 153 Error error; 154 m_get_item_info_impl_code.reset( 155 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 156 g_get_item_info_function_code, eLanguageTypeObjC, 157 g_get_item_info_function_name, error)); 158 if (error.Fail()) { 159 if (log) 160 log->Printf("Failed to get utility function: %s.", 161 error.AsCString()); 162 return args_addr; 163 } 164 165 if (!m_get_item_info_impl_code->Install(diagnostics, exe_ctx)) { 166 if (log) { 167 log->Printf("Failed to install get-item-info introspection."); 168 diagnostics.Dump(log); 169 } 170 m_get_item_info_impl_code.reset(); 171 return args_addr; 172 } 173 } else { 174 if (log) 175 log->Printf("No get-item-info introspection code found."); 176 return LLDB_INVALID_ADDRESS; 177 } 178 179 // Next make the runner function for our implementation utility function. 180 Error error; 181 182 TypeSystem *type_system = 183 thread.GetProcess()->GetTarget().GetScratchTypeSystemForLanguage( 184 nullptr, eLanguageTypeC); 185 CompilerType get_item_info_return_type = 186 type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType(); 187 188 get_item_info_caller = m_get_item_info_impl_code->MakeFunctionCaller( 189 get_item_info_return_type, get_item_info_arglist, 190 thread.shared_from_this(), error); 191 if (error.Fail()) { 192 if (log) 193 log->Printf("Error Inserting get-item-info function: \"%s\".", 194 error.AsCString()); 195 return args_addr; 196 } 197 } else { 198 // If it's already made, then we can just retrieve the caller: 199 get_item_info_caller = m_get_item_info_impl_code->GetFunctionCaller(); 200 if (!get_item_info_caller) { 201 if (log) 202 log->Printf("Failed to get get-item-info introspection caller."); 203 m_get_item_info_impl_code.reset(); 204 return args_addr; 205 } 206 } 207 } 208 209 diagnostics.Clear(); 210 211 // Now write down the argument values for this particular call. This looks 212 // like it might be a race condition 213 // if other threads were calling into here, but actually it isn't because we 214 // allocate a new args structure for 215 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 216 217 if (!get_item_info_caller->WriteFunctionArguments( 218 exe_ctx, args_addr, get_item_info_arglist, diagnostics)) { 219 if (log) { 220 log->Printf("Error writing get-item-info function arguments."); 221 diagnostics.Dump(log); 222 } 223 224 return args_addr; 225 } 226 227 return args_addr; 228 } 229 230 AppleGetItemInfoHandler::GetItemInfoReturnInfo 231 AppleGetItemInfoHandler::GetItemInfo(Thread &thread, uint64_t item, 232 addr_t page_to_free, 233 uint64_t page_to_free_size, Error &error) { 234 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 235 ProcessSP process_sp(thread.CalculateProcess()); 236 TargetSP target_sp(thread.CalculateTarget()); 237 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 238 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 239 240 GetItemInfoReturnInfo return_value; 241 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 242 return_value.item_buffer_size = 0; 243 244 error.Clear(); 245 246 if (thread.SafeToCallFunctions() == false) { 247 if (log) 248 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 249 thread.GetID()); 250 error.SetErrorString("Not safe to call functions on this thread."); 251 return return_value; 252 } 253 254 // Set up the arguments for a call to 255 256 // struct get_item_info_return_values 257 // { 258 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 259 // from libBacktraceRecording */ 260 // uint64_t item_info_buffer_size; /* the size of the items buffer from 261 // libBacktraceRecording */ 262 // }; 263 // 264 // void __lldb_backtrace_recording_get_item_info 265 // (struct 266 // get_item_info_return_values 267 // *return_buffer, 268 // int debug, 269 // uint64_t item, 270 // void *page_to_free, 271 // uint64_t page_to_free_size) 272 273 // Where the return_buffer argument points to a 24 byte region of memory 274 // already allocated by lldb in 275 // the inferior process. 276 277 CompilerType clang_void_ptr_type = 278 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 279 Value return_buffer_ptr_value; 280 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 281 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 282 283 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 284 Value debug_value; 285 debug_value.SetValueType(Value::eValueTypeScalar); 286 debug_value.SetCompilerType(clang_int_type); 287 288 CompilerType clang_uint64_type = 289 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 290 Value item_value; 291 item_value.SetValueType(Value::eValueTypeScalar); 292 item_value.SetCompilerType(clang_uint64_type); 293 294 Value page_to_free_value; 295 page_to_free_value.SetValueType(Value::eValueTypeScalar); 296 page_to_free_value.SetCompilerType(clang_void_ptr_type); 297 298 Value page_to_free_size_value; 299 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 300 page_to_free_size_value.SetCompilerType(clang_uint64_type); 301 302 std::lock_guard<std::mutex> guard(m_get_item_info_retbuffer_mutex); 303 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 304 addr_t bufaddr = process_sp->AllocateMemory( 305 32, ePermissionsReadable | ePermissionsWritable, error); 306 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 307 if (log) 308 log->Printf("Failed to allocate memory for return buffer for get " 309 "current queues func call"); 310 return return_value; 311 } 312 m_get_item_info_return_buffer_addr = bufaddr; 313 } 314 315 ValueList argument_values; 316 317 return_buffer_ptr_value.GetScalar() = m_get_item_info_return_buffer_addr; 318 argument_values.PushValue(return_buffer_ptr_value); 319 320 debug_value.GetScalar() = 0; 321 argument_values.PushValue(debug_value); 322 323 item_value.GetScalar() = item; 324 argument_values.PushValue(item_value); 325 326 if (page_to_free != LLDB_INVALID_ADDRESS) 327 page_to_free_value.GetScalar() = page_to_free; 328 else 329 page_to_free_value.GetScalar() = 0; 330 argument_values.PushValue(page_to_free_value); 331 332 page_to_free_size_value.GetScalar() = page_to_free_size; 333 argument_values.PushValue(page_to_free_size_value); 334 335 addr_t args_addr = SetupGetItemInfoFunction(thread, argument_values); 336 337 DiagnosticManager diagnostics; 338 ExecutionContext exe_ctx; 339 EvaluateExpressionOptions options; 340 options.SetUnwindOnError(true); 341 options.SetIgnoreBreakpoints(true); 342 options.SetStopOthers(true); 343 options.SetTimeoutUsec(500000); 344 options.SetTryAllThreads(false); 345 thread.CalculateExecutionContext(exe_ctx); 346 347 if (!m_get_item_info_impl_code) { 348 error.SetErrorString("Unable to compile function to call " 349 "__introspection_dispatch_queue_item_get_info"); 350 return return_value; 351 } 352 353 ExpressionResults func_call_ret; 354 Value results; 355 FunctionCaller *func_caller = m_get_item_info_impl_code->GetFunctionCaller(); 356 if (!func_caller) { 357 if (log) 358 log->Printf("Could not retrieve function caller for " 359 "__introspection_dispatch_queue_item_get_info."); 360 error.SetErrorString("Could not retrieve function caller for " 361 "__introspection_dispatch_queue_item_get_info."); 362 return return_value; 363 } 364 365 func_call_ret = func_caller->ExecuteFunction(exe_ctx, &args_addr, options, 366 diagnostics, results); 367 if (func_call_ret != eExpressionCompleted || !error.Success()) { 368 if (log) 369 log->Printf("Unable to call " 370 "__introspection_dispatch_queue_item_get_info(), got " 371 "ExpressionResults %d, error contains %s", 372 func_call_ret, error.AsCString("")); 373 error.SetErrorString("Unable to call " 374 "__introspection_dispatch_queue_get_item_info() for " 375 "list of queues"); 376 return return_value; 377 } 378 379 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 380 m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 381 if (!error.Success() || 382 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { 383 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 384 return return_value; 385 } 386 387 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 388 m_get_item_info_return_buffer_addr + 8, 8, 0, error); 389 390 if (!error.Success()) { 391 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 392 return return_value; 393 } 394 if (log) 395 log->Printf("AppleGetItemInfoHandler called " 396 "__introspection_dispatch_queue_item_get_info (page_to_free == " 397 "0x%" PRIx64 ", size = %" PRId64 398 "), returned page is at 0x%" PRIx64 ", size %" PRId64, 399 page_to_free, page_to_free_size, return_value.item_buffer_ptr, 400 return_value.item_buffer_size); 401 402 return return_value; 403 } 404