1 //===-- AppleGetItemInfoHandler.cpp -------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "AppleGetItemInfoHandler.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 17 #include "lldb/Core/ConstString.h" 18 #include "lldb/Core/Log.h" 19 #include "lldb/Core/Module.h" 20 #include "lldb/Core/StreamString.h" 21 #include "lldb/Core/Value.h" 22 #include "lldb/Expression/DiagnosticManager.h" 23 #include "lldb/Expression/FunctionCaller.h" 24 #include "lldb/Expression/UtilityFunction.h" 25 #include "lldb/Symbol/ClangASTContext.h" 26 #include "lldb/Symbol/Symbol.h" 27 #include "lldb/Target/ExecutionContext.h" 28 #include "lldb/Target/Process.h" 29 #include "lldb/Target/Target.h" 30 #include "lldb/Target/Thread.h" 31 32 using namespace lldb; 33 using namespace lldb_private; 34 35 const char *AppleGetItemInfoHandler::g_get_item_info_function_name = "__lldb_backtrace_recording_get_item_info"; 36 const char *AppleGetItemInfoHandler::g_get_item_info_function_code = " \n\ 37 extern \"C\" \n\ 38 { \n\ 39 /* \n\ 40 * mach defines \n\ 41 */ \n\ 42 \n\ 43 typedef unsigned int uint32_t; \n\ 44 typedef unsigned long long uint64_t; \n\ 45 typedef uint32_t mach_port_t; \n\ 46 typedef mach_port_t vm_map_t; \n\ 47 typedef int kern_return_t; \n\ 48 typedef uint64_t mach_vm_address_t; \n\ 49 typedef uint64_t mach_vm_size_t; \n\ 50 \n\ 51 mach_port_t mach_task_self (); \n\ 52 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 53 \n\ 54 /* \n\ 55 * libBacktraceRecording defines \n\ 56 */ \n\ 57 \n\ 58 typedef uint32_t queue_list_scope_t; \n\ 59 typedef void *dispatch_queue_t; \n\ 60 typedef void *introspection_dispatch_queue_info_t; \n\ 61 typedef void *introspection_dispatch_item_info_ref; \n\ 62 \n\ 63 extern uint64_t __introspection_dispatch_queue_item_get_info (introspection_dispatch_item_info_ref item_info_ref, \n\ 64 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 65 uint64_t *returned_queues_buffer_size); \n\ 66 extern int printf(const char *format, ...); \n\ 67 \n\ 68 /* \n\ 69 * return type define \n\ 70 */ \n\ 71 \n\ 72 struct get_item_info_return_values \n\ 73 { \n\ 74 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 75 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 76 }; \n\ 77 \n\ 78 void __lldb_backtrace_recording_get_item_info \n\ 79 (struct get_item_info_return_values *return_buffer, \n\ 80 int debug, \n\ 81 uint64_t /* introspection_dispatch_item_info_ref item_info_ref */ item, \n\ 82 void *page_to_free, \n\ 83 uint64_t page_to_free_size) \n\ 84 { \n\ 85 if (debug) \n\ 86 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\ 87 if (page_to_free != 0) \n\ 88 { \n\ 89 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 90 } \n\ 91 \n\ 92 __introspection_dispatch_queue_item_get_info ((void*) item, \n\ 93 (void**)&return_buffer->item_info_buffer_ptr, \n\ 94 &return_buffer->item_info_buffer_size); \n\ 95 } \n\ 96 } \n\ 97 "; 98 99 AppleGetItemInfoHandler::AppleGetItemInfoHandler (Process *process) : 100 m_process (process), 101 m_get_item_info_impl_code (), 102 m_get_item_info_function_mutex(), 103 m_get_item_info_return_buffer_addr (LLDB_INVALID_ADDRESS), 104 m_get_item_info_retbuffer_mutex() 105 { 106 } 107 108 AppleGetItemInfoHandler::~AppleGetItemInfoHandler () 109 { 110 } 111 112 void 113 AppleGetItemInfoHandler::Detach () 114 { 115 116 if (m_process && m_process->IsAlive() && m_get_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) 117 { 118 Mutex::Locker locker; 119 locker.TryLock (m_get_item_info_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 120 m_process->DeallocateMemory (m_get_item_info_return_buffer_addr); 121 } 122 } 123 124 // Compile our __lldb_backtrace_recording_get_item_info() function (from the 125 // source above in g_get_item_info_function_code) if we don't find that function in the inferior 126 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 127 // 128 // Insert the __lldb_backtrace_recording_get_item_info into the inferior process if needed. 129 // 130 // Write the get_item_info_arglist into the inferior's memory space to prepare for the call. 131 // 132 // Returns the address of the arguments written down in the inferior process, which can be used to 133 // make the function call. 134 135 lldb::addr_t 136 AppleGetItemInfoHandler::SetupGetItemInfoFunction(Thread &thread, ValueList &get_item_info_arglist) 137 { 138 ExecutionContext exe_ctx(thread.shared_from_this()); 139 DiagnosticManager diagnostics; 140 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 141 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 142 FunctionCaller *get_item_info_caller = nullptr; 143 144 // Scope for mutex locker: 145 { 146 Mutex::Locker locker(m_get_item_info_function_mutex); 147 148 // First stage is to make the UtilityFunction to hold our injected function: 149 150 if (!m_get_item_info_impl_code.get()) 151 { 152 if (g_get_item_info_function_code != NULL) 153 { 154 Error error; 155 m_get_item_info_impl_code.reset(exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage (g_get_item_info_function_code, 156 eLanguageTypeObjC, 157 g_get_item_info_function_name, 158 error)); 159 if (error.Fail()) 160 { 161 if (log) 162 log->Printf ("Failed to get utility function: %s.", error.AsCString()); 163 return args_addr; 164 } 165 166 if (!m_get_item_info_impl_code->Install(diagnostics, exe_ctx)) 167 { 168 if (log) 169 { 170 log->Printf("Failed to install get-item-info introspection."); 171 diagnostics.Dump(log); 172 } 173 m_get_item_info_impl_code.reset(); 174 return args_addr; 175 } 176 } 177 else 178 { 179 if (log) 180 log->Printf("No get-item-info introspection code found."); 181 return LLDB_INVALID_ADDRESS; 182 } 183 184 // Next make the runner function for our implementation utility function. 185 Error error; 186 187 TypeSystem *type_system = thread.GetProcess()->GetTarget().GetScratchTypeSystemForLanguage(nullptr, eLanguageTypeC); 188 CompilerType get_item_info_return_type = type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType(); 189 190 get_item_info_caller = m_get_item_info_impl_code->MakeFunctionCaller(get_item_info_return_type, 191 get_item_info_arglist, 192 thread.shared_from_this(), 193 error); 194 if (error.Fail()) 195 { 196 if (log) 197 log->Printf ("Error Inserting get-item-info function: \"%s\".", error.AsCString()); 198 return args_addr; 199 } 200 } 201 else 202 { 203 // If it's already made, then we can just retrieve the caller: 204 get_item_info_caller = m_get_item_info_impl_code->GetFunctionCaller(); 205 if (!get_item_info_caller) 206 { 207 if (log) 208 log->Printf ("Failed to get get-item-info introspection caller."); 209 m_get_item_info_impl_code.reset(); 210 return args_addr; 211 } 212 } 213 } 214 215 diagnostics.Clear(); 216 217 // Now write down the argument values for this particular call. This looks like it might be a race condition 218 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 219 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 220 221 if (!get_item_info_caller->WriteFunctionArguments(exe_ctx, args_addr, get_item_info_arglist, diagnostics)) 222 { 223 if (log) 224 { 225 log->Printf("Error writing get-item-info function arguments."); 226 diagnostics.Dump(log); 227 } 228 229 return args_addr; 230 } 231 232 return args_addr; 233 } 234 235 AppleGetItemInfoHandler::GetItemInfoReturnInfo 236 AppleGetItemInfoHandler::GetItemInfo (Thread &thread, uint64_t item, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 237 { 238 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 239 ProcessSP process_sp (thread.CalculateProcess()); 240 TargetSP target_sp (thread.CalculateTarget()); 241 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 242 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 243 244 GetItemInfoReturnInfo return_value; 245 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 246 return_value.item_buffer_size = 0; 247 248 error.Clear(); 249 250 if (thread.SafeToCallFunctions() == false) 251 { 252 if (log) 253 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 254 error.SetErrorString ("Not safe to call functions on this thread."); 255 return return_value; 256 } 257 258 // Set up the arguments for a call to 259 260 // struct get_item_info_return_values 261 // { 262 // uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ 263 // uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ 264 // }; 265 // 266 // void __lldb_backtrace_recording_get_item_info 267 // (struct get_item_info_return_values *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 already allocated by lldb in 274 // the inferior process. 275 276 CompilerType clang_void_ptr_type = 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 = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 287 Value item_value; 288 item_value.SetValueType (Value::eValueTypeScalar); 289 item_value.SetCompilerType (clang_uint64_type); 290 291 Value page_to_free_value; 292 page_to_free_value.SetValueType (Value::eValueTypeScalar); 293 page_to_free_value.SetCompilerType (clang_void_ptr_type); 294 295 Value page_to_free_size_value; 296 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 297 page_to_free_size_value.SetCompilerType (clang_uint64_type); 298 299 300 Mutex::Locker locker(m_get_item_info_retbuffer_mutex); 301 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) 302 { 303 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 304 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 305 { 306 if (log) 307 log->Printf ("Failed to allocate memory for return buffer for get 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.SetTimeoutUsec(500000); 342 options.SetTryAllThreads (false); 343 thread.CalculateExecutionContext (exe_ctx); 344 345 if (!m_get_item_info_impl_code) 346 { 347 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_item_get_info"); 348 return return_value; 349 } 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 { 357 if (log) 358 log->Printf ("Could not retrieve function caller for __introspection_dispatch_queue_item_get_info."); 359 error.SetErrorString("Could not retrieve function caller for __introspection_dispatch_queue_item_get_info."); 360 return return_value; 361 } 362 363 func_call_ret = func_caller->ExecuteFunction(exe_ctx, &args_addr, options, diagnostics, results); 364 if (func_call_ret != eExpressionCompleted || !error.Success()) 365 { 366 if (log) 367 log->Printf ("Unable to call __introspection_dispatch_queue_item_get_info(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 368 error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_item_info() for list of queues"); 369 return return_value; 370 } 371 372 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 373 if (!error.Success() || return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) 374 { 375 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 376 return return_value; 377 } 378 379 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_item_info_return_buffer_addr + 8, 8, 0, error); 380 381 if (!error.Success()) 382 { 383 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 384 return return_value; 385 } 386 if (log) 387 log->Printf ("AppleGetItemInfoHandler called __introspection_dispatch_queue_item_get_info (page_to_free == 0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64 ", size %" PRId64, page_to_free, page_to_free_size, return_value.item_buffer_ptr, return_value.item_buffer_size); 388 389 390 return return_value; 391 } 392