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 "clang/AST/ASTContext.h" 18 #include "clang/AST/DeclCXX.h" 19 20 #include "lldb/Core/ConstString.h" 21 #include "lldb/Core/Log.h" 22 #include "lldb/Core/Module.h" 23 #include "lldb/Core/StreamString.h" 24 #include "lldb/Core/Value.h" 25 #include "lldb/Expression/ClangExpression.h" 26 #include "lldb/Expression/ClangFunction.h" 27 #include "lldb/Expression/ClangUtilityFunction.h" 28 #include "lldb/Symbol/ClangASTContext.h" 29 #include "lldb/Symbol/Symbol.h" 30 #include "lldb/Target/ExecutionContext.h" 31 #include "lldb/Target/Process.h" 32 #include "lldb/Target/Target.h" 33 #include "lldb/Target/Thread.h" 34 35 using namespace lldb; 36 using namespace lldb_private; 37 38 const char *AppleGetItemInfoHandler::g_get_item_info_function_name = "__lldb_backtrace_recording_get_item_info"; 39 const char *AppleGetItemInfoHandler::g_get_item_info_function_code = " \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), 104 m_get_item_info_function (), 105 m_get_item_info_impl_code (), 106 m_get_item_info_function_mutex(), 107 m_get_item_info_return_buffer_addr (LLDB_INVALID_ADDRESS), 108 m_get_item_info_retbuffer_mutex() 109 { 110 } 111 112 AppleGetItemInfoHandler::~AppleGetItemInfoHandler () 113 { 114 } 115 116 void 117 AppleGetItemInfoHandler::Detach () 118 { 119 120 if (m_process && m_process->IsAlive() && m_get_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) 121 { 122 Mutex::Locker locker; 123 locker.TryLock (m_get_item_info_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 124 m_process->DeallocateMemory (m_get_item_info_return_buffer_addr); 125 } 126 } 127 128 // Compile our __lldb_backtrace_recording_get_item_info() function (from the 129 // source above in g_get_item_info_function_code) if we don't find that function in the inferior 130 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 131 // 132 // Insert the __lldb_backtrace_recording_get_item_info into the inferior process if needed. 133 // 134 // Write the get_item_info_arglist into the inferior's memory space to prepare for the call. 135 // 136 // Returns the address of the arguments written down in the inferior process, which can be used to 137 // make the function call. 138 139 lldb::addr_t 140 AppleGetItemInfoHandler::SetupGetItemInfoFunction (Thread &thread, ValueList &get_item_info_arglist) 141 { 142 ExecutionContext exe_ctx (thread.shared_from_this()); 143 Address impl_code_address; 144 StreamString errors; 145 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 146 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 147 148 // Scope for mutex locker: 149 { 150 Mutex::Locker locker(m_get_item_info_function_mutex); 151 152 // First stage is to make the ClangUtility to hold our injected function: 153 154 #define USE_BUILTIN_FUNCTION 0 // Define this to 1 and we will use the get_implementation function found in the target. 155 // This is useful for debugging additions to the get_impl function 'cause you don't have 156 // to bother with string-ifying the code into g_get_item_info_function_code. 157 158 if (USE_BUILTIN_FUNCTION) 159 { 160 ConstString our_utility_function_name("__lldb_backtrace_recording_get_item_info"); 161 SymbolContextList sc_list; 162 163 exe_ctx.GetTargetRef().GetImages().FindSymbolsWithNameAndType (our_utility_function_name, eSymbolTypeCode, sc_list); 164 if (sc_list.GetSize() == 1) 165 { 166 SymbolContext sc; 167 sc_list.GetContextAtIndex(0, sc); 168 if (sc.symbol != NULL) 169 impl_code_address = sc.symbol->GetAddress(); 170 171 //lldb::addr_t addr = impl_code_address.GetOpcodeLoadAddress (exe_ctx.GetTargetPtr()); 172 //printf ("Getting address for our_utility_function: 0x%" PRIx64 ".\n", addr); 173 } 174 else 175 { 176 //printf ("Could not find queues introspection function address.\n"); 177 return args_addr; 178 } 179 } 180 else if (!m_get_item_info_impl_code.get()) 181 { 182 if (g_get_item_info_function_code != NULL) 183 { 184 m_get_item_info_impl_code.reset (new ClangUtilityFunction (g_get_item_info_function_code, 185 g_get_item_info_function_name)); 186 if (!m_get_item_info_impl_code->Install(errors, exe_ctx)) 187 { 188 if (log) 189 log->Printf ("Failed to install get-item-info introspection: %s.", errors.GetData()); 190 m_get_item_info_impl_code.reset(); 191 return args_addr; 192 } 193 } 194 else 195 { 196 if (log) 197 log->Printf("No get-item-info introspection code found."); 198 errors.Printf ("No get-item-info introspection code found."); 199 return LLDB_INVALID_ADDRESS; 200 } 201 202 impl_code_address.Clear(); 203 impl_code_address.SetOffset(m_get_item_info_impl_code->StartAddress()); 204 } 205 else 206 { 207 impl_code_address.Clear(); 208 impl_code_address.SetOffset(m_get_item_info_impl_code->StartAddress()); 209 } 210 211 // Next make the runner function for our implementation utility function. 212 if (!m_get_item_info_function.get()) 213 { 214 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 215 ClangASTType get_item_info_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 216 m_get_item_info_function.reset(new ClangFunction (thread, 217 get_item_info_return_type, 218 impl_code_address, 219 get_item_info_arglist, 220 "queue-bt-item-info")); 221 222 errors.Clear(); 223 unsigned num_errors = m_get_item_info_function->CompileFunction(errors); 224 if (num_errors) 225 { 226 if (log) 227 log->Printf ("Error compiling get-item-info function: \"%s\".", errors.GetData()); 228 return args_addr; 229 } 230 231 errors.Clear(); 232 if (!m_get_item_info_function->WriteFunctionWrapper(exe_ctx, errors)) 233 { 234 if (log) 235 log->Printf ("Error Inserting get-item-info function: \"%s\".", errors.GetData()); 236 return args_addr; 237 } 238 } 239 } 240 241 errors.Clear(); 242 243 // Now write down the argument values for this particular call. This looks like it might be a race condition 244 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 245 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 246 247 if (!m_get_item_info_function->WriteFunctionArguments (exe_ctx, args_addr, impl_code_address, get_item_info_arglist, errors)) 248 { 249 if (log) 250 log->Printf ("Error writing get-item-info function arguments: \"%s\".", errors.GetData()); 251 return args_addr; 252 } 253 254 return args_addr; 255 } 256 257 AppleGetItemInfoHandler::GetItemInfoReturnInfo 258 AppleGetItemInfoHandler::GetItemInfo (Thread &thread, uint64_t item, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 259 { 260 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 261 ProcessSP process_sp (thread.CalculateProcess()); 262 TargetSP target_sp (thread.CalculateTarget()); 263 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 264 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 265 266 GetItemInfoReturnInfo return_value; 267 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 268 return_value.item_buffer_size = 0; 269 270 error.Clear(); 271 272 if (thread.SafeToCallFunctions() == false) 273 { 274 if (log) 275 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 276 error.SetErrorString ("Not safe to call functions on this thread."); 277 return return_value; 278 } 279 280 // Set up the arguments for a call to 281 282 // struct get_item_info_return_values 283 // { 284 // uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ 285 // uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ 286 // }; 287 // 288 // void __lldb_backtrace_recording_get_item_info 289 // (struct get_item_info_return_values *return_buffer, 290 // int debug, 291 // uint64_t item, 292 // void *page_to_free, 293 // uint64_t page_to_free_size) 294 295 // Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in 296 // the inferior process. 297 298 ClangASTType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 299 Value return_buffer_ptr_value; 300 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 301 return_buffer_ptr_value.SetClangType (clang_void_ptr_type); 302 303 ClangASTType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 304 Value debug_value; 305 debug_value.SetValueType (Value::eValueTypeScalar); 306 debug_value.SetClangType (clang_int_type); 307 308 ClangASTType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 309 Value item_value; 310 item_value.SetValueType (Value::eValueTypeScalar); 311 item_value.SetClangType (clang_uint64_type); 312 313 Value page_to_free_value; 314 page_to_free_value.SetValueType (Value::eValueTypeScalar); 315 page_to_free_value.SetClangType (clang_void_ptr_type); 316 317 Value page_to_free_size_value; 318 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 319 page_to_free_size_value.SetClangType (clang_uint64_type); 320 321 322 Mutex::Locker locker(m_get_item_info_retbuffer_mutex); 323 if (m_get_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) 324 { 325 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 326 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 327 { 328 if (log) 329 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 330 return return_value; 331 } 332 m_get_item_info_return_buffer_addr = bufaddr; 333 } 334 335 ValueList argument_values; 336 337 return_buffer_ptr_value.GetScalar() = m_get_item_info_return_buffer_addr; 338 argument_values.PushValue (return_buffer_ptr_value); 339 340 debug_value.GetScalar() = 0; 341 argument_values.PushValue (debug_value); 342 343 item_value.GetScalar() = item; 344 argument_values.PushValue (item_value); 345 346 if (page_to_free != LLDB_INVALID_ADDRESS) 347 page_to_free_value.GetScalar() = page_to_free; 348 else 349 page_to_free_value.GetScalar() = 0; 350 argument_values.PushValue (page_to_free_value); 351 352 page_to_free_size_value.GetScalar() = page_to_free_size; 353 argument_values.PushValue (page_to_free_size_value); 354 355 addr_t args_addr = SetupGetItemInfoFunction (thread, argument_values); 356 357 StreamString errors; 358 ExecutionContext exe_ctx; 359 EvaluateExpressionOptions options; 360 options.SetUnwindOnError (true); 361 options.SetIgnoreBreakpoints (true); 362 options.SetStopOthers (true); 363 options.SetTimeoutUsec(500000); 364 options.SetTryAllThreads (false); 365 thread.CalculateExecutionContext (exe_ctx); 366 367 if (m_get_item_info_function == NULL) 368 { 369 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_item_get_info"); 370 return return_value; 371 } 372 373 374 ExpressionResults func_call_ret; 375 Value results; 376 func_call_ret = m_get_item_info_function->ExecuteFunction (exe_ctx, &args_addr, options, errors, results); 377 if (func_call_ret != eExpressionCompleted || !error.Success()) 378 { 379 if (log) 380 log->Printf ("Unable to call __introspection_dispatch_queue_item_get_info(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 381 error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_item_info() for list of queues"); 382 return return_value; 383 } 384 385 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 386 if (!error.Success() || return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) 387 { 388 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 389 return return_value; 390 } 391 392 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_item_info_return_buffer_addr + 8, 8, 0, error); 393 394 if (!error.Success()) 395 { 396 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 397 return return_value; 398 } 399 if (log) 400 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); 401 402 403 return return_value; 404 } 405