1 //===-- AppleGetQueuesHandler.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 "AppleGetQueuesHandler.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 #include "AppleThreadPlanStepThroughObjCTrampoline.h" 17 18 #include "clang/AST/ASTContext.h" 19 #include "clang/AST/DeclCXX.h" 20 21 #include "lldb/Core/ConstString.h" 22 #include "lldb/Core/Log.h" 23 #include "lldb/Core/Module.h" 24 #include "lldb/Core/StreamString.h" 25 #include "lldb/Core/Value.h" 26 #include "lldb/Expression/ClangExpression.h" 27 #include "lldb/Expression/ClangFunction.h" 28 #include "lldb/Expression/ClangUtilityFunction.h" 29 #include "lldb/Symbol/ClangASTContext.h" 30 #include "lldb/Symbol/Symbol.h" 31 #include "lldb/Target/ExecutionContext.h" 32 #include "lldb/Target/Process.h" 33 34 using namespace lldb; 35 using namespace lldb_private; 36 37 const char *AppleGetQueuesHandler::g_get_current_queues_function_name = "__lldb_backtrace_recording_get_current_queues"; 38 const char *AppleGetQueuesHandler::g_get_current_queues_function_code = " \n\ 39 extern \"C\" \n\ 40 { \n\ 41 /* \n\ 42 * mach defines \n\ 43 */ \n\ 44 \n\ 45 typedef unsigned int uint32_t; \n\ 46 typedef unsigned long long uint64_t; \n\ 47 typedef uint32_t mach_port_t; \n\ 48 typedef mach_port_t vm_map_t; \n\ 49 typedef int kern_return_t; \n\ 50 typedef uint64_t mach_vm_address_t; \n\ 51 typedef uint64_t mach_vm_size_t; \n\ 52 \n\ 53 mach_port_t mach_task_self (); \n\ 54 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 55 \n\ 56 /* \n\ 57 * libBacktraceRecording defines \n\ 58 */ \n\ 59 \n\ 60 typedef uint32_t queue_list_scope_t; \n\ 61 typedef void *introspection_dispatch_queue_info_t; \n\ 62 \n\ 63 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ 64 introspection_dispatch_queue_info_t *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_current_queues_return_values \n\ 73 { \n\ 74 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ 75 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ 76 uint64_t count; /* the number of queues included in the queues buffer */ \n\ 77 }; \n\ 78 \n\ 79 void __lldb_backtrace_recording_get_current_queues \n\ 80 (struct get_current_queues_return_values *return_buffer, \n\ 81 int debug, \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_current_queues with args %p, %d, 0x%p, 0x%llx\\n\", return_buffer, debug, 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 return_buffer->count = __introspection_dispatch_get_queues ( \n\ 93 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ 94 (void**)&return_buffer->queues_buffer_ptr, \n\ 95 &return_buffer->queues_buffer_size); \n\ 96 if (debug) \n\ 97 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 98 } \n\ 99 } \n\ 100 "; 101 102 AppleGetQueuesHandler::AppleGetQueuesHandler (Process *process) : 103 m_process (process), 104 m_get_queues_function (), 105 m_get_queues_impl_code (), 106 m_get_queues_function_mutex(), 107 m_get_queues_return_buffer_addr (LLDB_INVALID_ADDRESS), 108 m_get_queues_retbuffer_mutex() 109 { 110 } 111 112 AppleGetQueuesHandler::~AppleGetQueuesHandler () 113 { 114 } 115 116 void 117 AppleGetQueuesHandler::Detach () 118 { 119 120 if (m_process && m_process->IsAlive() && m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) 121 { 122 Mutex::Locker locker; 123 locker.TryLock (m_get_queues_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 124 m_process->DeallocateMemory (m_get_queues_return_buffer_addr); 125 } 126 } 127 128 // Construct a ClangASTType for the structure that g_get_current_queues_function_code will return by value 129 // so we can extract the fields after performing the function call. 130 // i.e. we are getting this struct returned to us: 131 // 132 // struct get_current_queues_return_values 133 // { 134 // introspection_dispatch_queue_info_t *queues_buffer; 135 // uint64_t queues_buffer_size; 136 // uint64_t count; 137 // }; 138 139 140 // Compile our __lldb_backtrace_recording_get_current_queues() function (from the 141 // source above in g_get_current_queues_function_code) if we don't find that function in the inferior 142 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 143 // 144 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior process if needed. 145 // 146 // Write the get_queues_arglist into the inferior's memory space to prepare for the call. 147 // 148 // Returns the address of the arguments written down in the inferior process, which can be used to 149 // make the function call. 150 151 lldb::addr_t 152 AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_queues_arglist) 153 { 154 ExecutionContext exe_ctx (thread.shared_from_this()); 155 Address impl_code_address; 156 StreamString errors; 157 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 158 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 159 160 // Scope for mutex locker: 161 { 162 Mutex::Locker locker(m_get_queues_function_mutex); 163 164 // First stage is to make the ClangUtility to hold our injected function: 165 166 #define USE_BUILTIN_FUNCTION 0 // Define this to 1 and we will use the get_implementation function found in the target. 167 // This is useful for debugging additions to the get_impl function 'cause you don't have 168 // to bother with string-ifying the code into g_get_current_queues_function_code. 169 170 if (USE_BUILTIN_FUNCTION) 171 { 172 ConstString our_utility_function_name("__lldb_backtrace_recording_get_current_queues"); 173 SymbolContextList sc_list; 174 175 exe_ctx.GetTargetRef().GetImages().FindSymbolsWithNameAndType (our_utility_function_name, eSymbolTypeCode, sc_list); 176 if (sc_list.GetSize() == 1) 177 { 178 SymbolContext sc; 179 sc_list.GetContextAtIndex(0, sc); 180 if (sc.symbol != NULL) 181 impl_code_address = sc.symbol->GetAddress(); 182 183 //lldb::addr_t addr = impl_code_address.GetOpcodeLoadAddress (exe_ctx.GetTargetPtr()); 184 //printf ("Getting address for our_utility_function: 0x%" PRIx64 ".\n", addr); 185 } 186 else 187 { 188 //printf ("Could not find queues introspection function address.\n"); 189 return args_addr; 190 } 191 } 192 else if (!m_get_queues_impl_code.get()) 193 { 194 if (g_get_current_queues_function_code != NULL) 195 { 196 m_get_queues_impl_code.reset (new ClangUtilityFunction (g_get_current_queues_function_code, 197 g_get_current_queues_function_name)); 198 if (!m_get_queues_impl_code->Install(errors, exe_ctx)) 199 { 200 if (log) 201 log->Printf ("Failed to install queues introspection: %s.", errors.GetData()); 202 m_get_queues_impl_code.reset(); 203 return args_addr; 204 } 205 } 206 else 207 { 208 if (log) 209 log->Printf("No queues introspection code found."); 210 errors.Printf ("No queues introspection code found."); 211 return LLDB_INVALID_ADDRESS; 212 } 213 214 impl_code_address.Clear(); 215 impl_code_address.SetOffset(m_get_queues_impl_code->StartAddress()); 216 } 217 else 218 { 219 impl_code_address.Clear(); 220 impl_code_address.SetOffset(m_get_queues_impl_code->StartAddress()); 221 } 222 223 // Next make the runner function for our implementation utility function. 224 if (!m_get_queues_function.get()) 225 { 226 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 227 ClangASTType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 228 m_get_queues_function.reset(new ClangFunction (thread, 229 get_queues_return_type, 230 impl_code_address, 231 get_queues_arglist, 232 "queue-fetch-queues")); 233 234 errors.Clear(); 235 unsigned num_errors = m_get_queues_function->CompileFunction(errors); 236 if (num_errors) 237 { 238 if (log) 239 log->Printf ("Error compiling get-queues function: \"%s\".", errors.GetData()); 240 return args_addr; 241 } 242 243 errors.Clear(); 244 if (!m_get_queues_function->WriteFunctionWrapper(exe_ctx, errors)) 245 { 246 if (log) 247 log->Printf ("Error Inserting get-queues function: \"%s\".", errors.GetData()); 248 return args_addr; 249 } 250 } 251 } 252 253 errors.Clear(); 254 255 // Now write down the argument values for this particular call. This looks like it might be a race condition 256 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 257 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 258 259 if (!m_get_queues_function->WriteFunctionArguments (exe_ctx, args_addr, impl_code_address, get_queues_arglist, errors)) 260 { 261 if (log) 262 log->Printf ("Error writing get-queues function arguments: \"%s\".", errors.GetData()); 263 return args_addr; 264 } 265 266 return args_addr; 267 } 268 269 AppleGetQueuesHandler::GetQueuesReturnInfo 270 AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 271 { 272 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 273 ProcessSP process_sp (thread.CalculateProcess()); 274 TargetSP target_sp (thread.CalculateTarget()); 275 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 276 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 277 278 GetQueuesReturnInfo return_value; 279 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 280 return_value.queues_buffer_size = 0; 281 return_value.count = 0; 282 283 error.Clear(); 284 285 if (thread.SafeToCallFunctions() == false) 286 { 287 if (log) 288 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 289 error.SetErrorString ("Not safe to call functions on this thread."); 290 return return_value; 291 } 292 293 // Set up the arguments for a call to 294 295 // struct get_current_queues_return_values 296 // { 297 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ 298 // uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ 299 // uint64_t count; /* the number of queues included in the queues buffer */ 300 // }; 301 // 302 // void 303 // __lldb_backtrace_recording_get_current_queues 304 // (struct get_current_queues_return_values *return_buffer, 305 // void *page_to_free, 306 // uint64_t page_to_free_size); 307 308 // Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in 309 // the inferior process. 310 311 ClangASTType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 312 Value return_buffer_ptr_value; 313 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 314 return_buffer_ptr_value.SetClangType (clang_void_ptr_type); 315 316 ClangASTType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 317 Value debug_value; 318 debug_value.SetValueType (Value::eValueTypeScalar); 319 debug_value.SetClangType (clang_int_type); 320 321 Value page_to_free_value; 322 page_to_free_value.SetValueType (Value::eValueTypeScalar); 323 page_to_free_value.SetClangType (clang_void_ptr_type); 324 325 ClangASTType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 326 Value page_to_free_size_value; 327 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 328 page_to_free_size_value.SetClangType (clang_uint64_type); 329 330 331 Mutex::Locker locker(m_get_queues_retbuffer_mutex); 332 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) 333 { 334 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 335 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 336 { 337 if (log) 338 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 339 return return_value; 340 } 341 m_get_queues_return_buffer_addr = bufaddr; 342 } 343 344 ValueList argument_values; 345 346 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 347 argument_values.PushValue (return_buffer_ptr_value); 348 349 debug_value.GetScalar() = 0; 350 argument_values.PushValue (debug_value); 351 352 if (page_to_free != LLDB_INVALID_ADDRESS) 353 page_to_free_value.GetScalar() = page_to_free; 354 else 355 page_to_free_value.GetScalar() = 0; 356 argument_values.PushValue (page_to_free_value); 357 358 page_to_free_size_value.GetScalar() = page_to_free_size; 359 argument_values.PushValue (page_to_free_size_value); 360 361 addr_t args_addr = SetupGetQueuesFunction (thread, argument_values); 362 363 if (m_get_queues_function == NULL) 364 { 365 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_get_queues"); 366 } 367 368 StreamString errors; 369 ExecutionContext exe_ctx; 370 EvaluateExpressionOptions options; 371 options.SetUnwindOnError (true); 372 options.SetIgnoreBreakpoints (true); 373 options.SetStopOthers (true); 374 options.SetTimeoutUsec(500000); 375 options.SetTryAllThreads (false); 376 thread.CalculateExecutionContext (exe_ctx); 377 378 ExpressionResults func_call_ret; 379 Value results; 380 func_call_ret = m_get_queues_function->ExecuteFunction (exe_ctx, &args_addr, options, errors, results); 381 if (func_call_ret != eExpressionCompleted || !error.Success()) 382 { 383 if (log) 384 log->Printf ("Unable to call introspection_get_dispatch_queues(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 385 error.SetErrorString ("Unable to call introspection_get_dispatch_queues() for list of queues"); 386 return return_value; 387 } 388 389 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 390 if (!error.Success() || return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) 391 { 392 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 393 return return_value; 394 } 395 396 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 8, 8, 0, error); 397 398 if (!error.Success()) 399 { 400 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 401 return return_value; 402 } 403 404 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 16, 8, 0, error); 405 if (!error.Success()) 406 { 407 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 408 return return_value; 409 } 410 411 if (log) 412 log->Printf ("AppleGetQueuesHandler called __introspection_dispatch_get_queues (page_to_free == 0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64 ", size %" PRId64 ", count = %" PRId64, page_to_free, page_to_free_size, return_value.queues_buffer_ptr, return_value.queues_buffer_size, return_value.count); 413 414 return return_value; 415 } 416