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