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 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 Status 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 Status 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() || get_item_info_caller == nullptr) { 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, 234 Status &error) { 235 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 236 ProcessSP process_sp(thread.CalculateProcess()); 237 TargetSP target_sp(thread.CalculateTarget()); 238 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 239 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 240 241 GetItemInfoReturnInfo return_value; 242 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 243 return_value.item_buffer_size = 0; 244 245 error.Clear(); 246 247 if (thread.SafeToCallFunctions() == false) { 248 if (log) 249 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 250 thread.GetID()); 251 error.SetErrorString("Not safe to call functions on this thread."); 252 return return_value; 253 } 254 255 // Set up the arguments for a call to 256 257 // struct get_item_info_return_values 258 // { 259 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 260 // from libBacktraceRecording */ 261 // uint64_t item_info_buffer_size; /* the size of the items buffer from 262 // libBacktraceRecording */ 263 // }; 264 // 265 // void __lldb_backtrace_recording_get_item_info 266 // (struct 267 // get_item_info_return_values 268 // *return_buffer, 269 // int debug, 270 // uint64_t item, 271 // void *page_to_free, 272 // uint64_t page_to_free_size) 273 274 // Where the return_buffer argument points to a 24 byte region of memory 275 // already allocated by lldb in 276 // the inferior process. 277 278 CompilerType clang_void_ptr_type = 279 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 280 Value return_buffer_ptr_value; 281 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 282 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 283 284 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 285 Value debug_value; 286 debug_value.SetValueType(Value::eValueTypeScalar); 287 debug_value.SetCompilerType(clang_int_type); 288 289 CompilerType clang_uint64_type = 290 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 291 Value item_value; 292 item_value.SetValueType(Value::eValueTypeScalar); 293 item_value.SetCompilerType(clang_uint64_type); 294 295 Value page_to_free_value; 296 page_to_free_value.SetValueType(Value::eValueTypeScalar); 297 page_to_free_value.SetCompilerType(clang_void_ptr_type); 298 299 Value page_to_free_size_value; 300 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 301 page_to_free_size_value.SetCompilerType(clang_uint64_type); 302 303 std::lock_guard<std::mutex> guard(m_get_item_info_retbuffer_mutex); 304 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 305 addr_t bufaddr = process_sp->AllocateMemory( 306 32, ePermissionsReadable | ePermissionsWritable, error); 307 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 308 if (log) 309 log->Printf("Failed to allocate memory for return buffer for get " 310 "current queues func call"); 311 return return_value; 312 } 313 m_get_item_info_return_buffer_addr = bufaddr; 314 } 315 316 ValueList argument_values; 317 318 return_buffer_ptr_value.GetScalar() = m_get_item_info_return_buffer_addr; 319 argument_values.PushValue(return_buffer_ptr_value); 320 321 debug_value.GetScalar() = 0; 322 argument_values.PushValue(debug_value); 323 324 item_value.GetScalar() = item; 325 argument_values.PushValue(item_value); 326 327 if (page_to_free != LLDB_INVALID_ADDRESS) 328 page_to_free_value.GetScalar() = page_to_free; 329 else 330 page_to_free_value.GetScalar() = 0; 331 argument_values.PushValue(page_to_free_value); 332 333 page_to_free_size_value.GetScalar() = page_to_free_size; 334 argument_values.PushValue(page_to_free_size_value); 335 336 addr_t args_addr = SetupGetItemInfoFunction(thread, argument_values); 337 338 DiagnosticManager diagnostics; 339 ExecutionContext exe_ctx; 340 EvaluateExpressionOptions options; 341 options.SetUnwindOnError(true); 342 options.SetIgnoreBreakpoints(true); 343 options.SetStopOthers(true); 344 options.SetTimeout(std::chrono::milliseconds(500)); 345 options.SetTryAllThreads(false); 346 thread.CalculateExecutionContext(exe_ctx); 347 348 if (!m_get_item_info_impl_code) { 349 error.SetErrorString("Unable to compile function to call " 350 "__introspection_dispatch_queue_item_get_info"); 351 return return_value; 352 } 353 354 ExpressionResults func_call_ret; 355 Value results; 356 FunctionCaller *func_caller = m_get_item_info_impl_code->GetFunctionCaller(); 357 if (!func_caller) { 358 if (log) 359 log->Printf("Could not retrieve function caller for " 360 "__introspection_dispatch_queue_item_get_info."); 361 error.SetErrorString("Could not retrieve function caller for " 362 "__introspection_dispatch_queue_item_get_info."); 363 return return_value; 364 } 365 366 func_call_ret = func_caller->ExecuteFunction(exe_ctx, &args_addr, options, 367 diagnostics, results); 368 if (func_call_ret != eExpressionCompleted || !error.Success()) { 369 if (log) 370 log->Printf("Unable to call " 371 "__introspection_dispatch_queue_item_get_info(), got " 372 "ExpressionResults %d, error contains %s", 373 func_call_ret, error.AsCString("")); 374 error.SetErrorString("Unable to call " 375 "__introspection_dispatch_queue_get_item_info() for " 376 "list of queues"); 377 return return_value; 378 } 379 380 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 381 m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 382 if (!error.Success() || 383 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { 384 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 385 return return_value; 386 } 387 388 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 389 m_get_item_info_return_buffer_addr + 8, 8, 0, error); 390 391 if (!error.Success()) { 392 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 393 return return_value; 394 } 395 if (log) 396 log->Printf("AppleGetItemInfoHandler called " 397 "__introspection_dispatch_queue_item_get_info (page_to_free == " 398 "0x%" PRIx64 ", size = %" PRId64 399 "), returned page is at 0x%" PRIx64 ", size %" PRId64, 400 page_to_free, page_to_free_size, return_value.item_buffer_ptr, 401 return_value.item_buffer_size); 402 403 return return_value; 404 } 405