1 //===-- AppleGetThreadItemInfoHandler.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 "AppleGetThreadItemInfoHandler.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/Expression.h" 22 #include "lldb/Expression/FunctionCaller.h" 23 #include "lldb/Expression/UtilityFunction.h" 24 #include "lldb/Symbol/ClangASTContext.h" 25 #include "lldb/Symbol/Symbol.h" 26 #include "lldb/Target/ExecutionContext.h" 27 #include "lldb/Target/Process.h" 28 #include "lldb/Target/StackFrame.h" 29 #include "lldb/Target/Target.h" 30 #include "lldb/Target/Thread.h" 31 #include "lldb/Utility/ConstString.h" 32 #include "lldb/Utility/Log.h" 33 #include "lldb/Utility/StreamString.h" 34 #include "lldb/lldb-private.h" 35 36 using namespace lldb; 37 using namespace lldb_private; 38 39 const char 40 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_name = 41 "__lldb_backtrace_recording_get_thread_item_info"; 42 const char 43 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_code = 44 " \n\ 45 extern \"C\" \n\ 46 { \n\ 47 /* \n\ 48 * mach defines \n\ 49 */ \n\ 50 \n\ 51 typedef unsigned int uint32_t; \n\ 52 typedef unsigned long long uint64_t; \n\ 53 typedef uint32_t mach_port_t; \n\ 54 typedef mach_port_t vm_map_t; \n\ 55 typedef int kern_return_t; \n\ 56 typedef uint64_t mach_vm_address_t; \n\ 57 typedef uint64_t mach_vm_size_t; \n\ 58 \n\ 59 mach_port_t mach_task_self (); \n\ 60 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 61 \n\ 62 typedef void *pthread_t; \n\ 63 extern int printf(const char *format, ...); \n\ 64 extern pthread_t pthread_self(void); \n\ 65 \n\ 66 /* \n\ 67 * libBacktraceRecording defines \n\ 68 */ \n\ 69 \n\ 70 typedef uint32_t queue_list_scope_t; \n\ 71 typedef void *dispatch_queue_t; \n\ 72 typedef void *introspection_dispatch_queue_info_t; \n\ 73 typedef void *introspection_dispatch_item_info_ref; \n\ 74 \n\ 75 extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\ 76 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 77 uint64_t *returned_queues_buffer_size); \n\ 78 \n\ 79 /* \n\ 80 * return type define \n\ 81 */ \n\ 82 \n\ 83 struct get_thread_item_info_return_values \n\ 84 { \n\ 85 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 86 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 87 }; \n\ 88 \n\ 89 void __lldb_backtrace_recording_get_thread_item_info \n\ 90 (struct get_thread_item_info_return_values *return_buffer, \n\ 91 int debug, \n\ 92 uint64_t thread_id, \n\ 93 void *page_to_free, \n\ 94 uint64_t page_to_free_size) \n\ 95 { \n\ 96 void *pthread_id = pthread_self (); \n\ 97 if (debug) \n\ 98 printf (\"entering get_thread_item_info with args return_buffer == %p, debug == %d, thread id == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, (uint64_t) thread_id, page_to_free, page_to_free_size); \n\ 99 if (page_to_free != 0) \n\ 100 { \n\ 101 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 102 } \n\ 103 \n\ 104 __introspection_dispatch_thread_get_item_info (thread_id, \n\ 105 (void**)&return_buffer->item_info_buffer_ptr, \n\ 106 &return_buffer->item_info_buffer_size); \n\ 107 } \n\ 108 } \n\ 109 "; 110 111 AppleGetThreadItemInfoHandler::AppleGetThreadItemInfoHandler(Process *process) 112 : m_process(process), m_get_thread_item_info_impl_code(), 113 m_get_thread_item_info_function_mutex(), 114 m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS), 115 m_get_thread_item_info_retbuffer_mutex() {} 116 117 AppleGetThreadItemInfoHandler::~AppleGetThreadItemInfoHandler() {} 118 119 void AppleGetThreadItemInfoHandler::Detach() { 120 121 if (m_process && m_process->IsAlive() && 122 m_get_thread_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) { 123 std::unique_lock<std::mutex> lock(m_get_thread_item_info_retbuffer_mutex, 124 std::defer_lock); 125 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 126 m_process->DeallocateMemory(m_get_thread_item_info_return_buffer_addr); 127 } 128 } 129 130 // Compile our __lldb_backtrace_recording_get_thread_item_info() function (from 131 // the source above in g_get_thread_item_info_function_code) if we don't find 132 // that function in the inferior already with USE_BUILTIN_FUNCTION defined. 133 // (e.g. this would be the case for testing.) 134 // 135 // Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior 136 // process if needed. 137 // 138 // Write the get_thread_item_info_arglist into the inferior's memory space to 139 // prepare for the call. 140 // 141 // Returns the address of the arguments written down in the inferior process, 142 // which can be used to make the function call. 143 144 lldb::addr_t AppleGetThreadItemInfoHandler::SetupGetThreadItemInfoFunction( 145 Thread &thread, ValueList &get_thread_item_info_arglist) { 146 ThreadSP thread_sp(thread.shared_from_this()); 147 ExecutionContext exe_ctx(thread_sp); 148 Address impl_code_address; 149 DiagnosticManager diagnostics; 150 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 151 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 152 FunctionCaller *get_thread_item_info_caller = nullptr; 153 154 // Scope for mutex locker: 155 { 156 std::lock_guard<std::mutex> guard(m_get_thread_item_info_function_mutex); 157 158 // First stage is to make the ClangUtility to hold our injected function: 159 160 if (!m_get_thread_item_info_impl_code.get()) { 161 Status error; 162 if (g_get_thread_item_info_function_code != NULL) { 163 m_get_thread_item_info_impl_code.reset( 164 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 165 g_get_thread_item_info_function_code, eLanguageTypeC, 166 g_get_thread_item_info_function_name, error)); 167 if (error.Fail()) { 168 if (log) 169 log->Printf("Failed to get UtilityFunction for " 170 "get-thread-item-info introspection: %s.", 171 error.AsCString()); 172 m_get_thread_item_info_impl_code.reset(); 173 return args_addr; 174 } 175 176 if (!m_get_thread_item_info_impl_code->Install(diagnostics, exe_ctx)) { 177 if (log) { 178 log->Printf( 179 "Failed to install get-thread-item-info introspection."); 180 diagnostics.Dump(log); 181 } 182 183 m_get_thread_item_info_impl_code.reset(); 184 return args_addr; 185 } 186 } else { 187 if (log) 188 log->Printf("No get-thread-item-info introspection code found."); 189 return LLDB_INVALID_ADDRESS; 190 } 191 192 // Also make the FunctionCaller for this UtilityFunction: 193 194 ClangASTContext *clang_ast_context = 195 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 196 CompilerType get_thread_item_info_return_type = 197 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 198 199 get_thread_item_info_caller = 200 m_get_thread_item_info_impl_code->MakeFunctionCaller( 201 get_thread_item_info_return_type, get_thread_item_info_arglist, 202 thread_sp, error); 203 if (error.Fail() || get_thread_item_info_caller == nullptr) { 204 if (log) 205 log->Printf("Failed to install get-thread-item-info introspection " 206 "caller: %s.", 207 error.AsCString()); 208 m_get_thread_item_info_impl_code.reset(); 209 return args_addr; 210 } 211 212 } else { 213 get_thread_item_info_caller = 214 m_get_thread_item_info_impl_code->GetFunctionCaller(); 215 } 216 } 217 218 diagnostics.Clear(); 219 220 // Now write down the argument values for this particular call. This looks 221 // like it might be a race condition if other threads were calling into here, 222 // but actually it isn't because we allocate a new args structure for this 223 // call by passing args_addr = LLDB_INVALID_ADDRESS... 224 225 if (!get_thread_item_info_caller->WriteFunctionArguments( 226 exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) { 227 if (log) { 228 log->Printf("Error writing get-thread-item-info function arguments"); 229 diagnostics.Dump(log); 230 } 231 return args_addr; 232 } 233 234 return args_addr; 235 } 236 237 AppleGetThreadItemInfoHandler::GetThreadItemInfoReturnInfo 238 AppleGetThreadItemInfoHandler::GetThreadItemInfo(Thread &thread, 239 tid_t thread_id, 240 addr_t page_to_free, 241 uint64_t page_to_free_size, 242 Status &error) { 243 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 244 ProcessSP process_sp(thread.CalculateProcess()); 245 TargetSP target_sp(thread.CalculateTarget()); 246 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 247 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 248 249 GetThreadItemInfoReturnInfo return_value; 250 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 251 return_value.item_buffer_size = 0; 252 253 error.Clear(); 254 255 if (thread.SafeToCallFunctions() == false) { 256 if (log) 257 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 258 thread.GetID()); 259 error.SetErrorString("Not safe to call functions on this thread."); 260 return return_value; 261 } 262 263 // Set up the arguments for a call to 264 265 // struct get_thread_item_info_return_values { 266 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 267 // from libBacktraceRecording */ 268 // uint64_t item_info_buffer_size; /* the size of the items buffer from 269 // libBacktraceRecording */ 270 // }; 271 // 272 // void __lldb_backtrace_recording_get_thread_item_info 273 // (struct 274 // get_thread_item_info_return_values 275 // *return_buffer, 276 // int debug, 277 // void *page_to_free, 278 // uint64_t page_to_free_size) 279 280 // Where the return_buffer argument points to a 24 byte region of memory 281 // already allocated by lldb in the inferior process. 282 283 CompilerType clang_void_ptr_type = 284 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 285 Value return_buffer_ptr_value; 286 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 287 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 288 289 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 290 Value debug_value; 291 debug_value.SetValueType(Value::eValueTypeScalar); 292 debug_value.SetCompilerType(clang_int_type); 293 294 CompilerType clang_uint64_type = 295 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 296 Value thread_id_value; 297 thread_id_value.SetValueType(Value::eValueTypeScalar); 298 thread_id_value.SetCompilerType(clang_uint64_type); 299 300 Value page_to_free_value; 301 page_to_free_value.SetValueType(Value::eValueTypeScalar); 302 page_to_free_value.SetCompilerType(clang_void_ptr_type); 303 304 Value page_to_free_size_value; 305 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 306 page_to_free_size_value.SetCompilerType(clang_uint64_type); 307 308 std::lock_guard<std::mutex> guard(m_get_thread_item_info_retbuffer_mutex); 309 if (m_get_thread_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 310 addr_t bufaddr = process_sp->AllocateMemory( 311 32, ePermissionsReadable | ePermissionsWritable, error); 312 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 313 if (log) 314 log->Printf("Failed to allocate memory for return buffer for get " 315 "current queues func call"); 316 return return_value; 317 } 318 m_get_thread_item_info_return_buffer_addr = bufaddr; 319 } 320 321 ValueList argument_values; 322 323 return_buffer_ptr_value.GetScalar() = 324 m_get_thread_item_info_return_buffer_addr; 325 argument_values.PushValue(return_buffer_ptr_value); 326 327 debug_value.GetScalar() = 0; 328 argument_values.PushValue(debug_value); 329 330 thread_id_value.GetScalar() = thread_id; 331 argument_values.PushValue(thread_id_value); 332 333 if (page_to_free != LLDB_INVALID_ADDRESS) 334 page_to_free_value.GetScalar() = page_to_free; 335 else 336 page_to_free_value.GetScalar() = 0; 337 argument_values.PushValue(page_to_free_value); 338 339 page_to_free_size_value.GetScalar() = page_to_free_size; 340 argument_values.PushValue(page_to_free_size_value); 341 342 addr_t args_addr = SetupGetThreadItemInfoFunction(thread, argument_values); 343 344 DiagnosticManager diagnostics; 345 ExecutionContext exe_ctx; 346 EvaluateExpressionOptions options; 347 FunctionCaller *get_thread_item_info_caller = nullptr; 348 349 options.SetUnwindOnError(true); 350 options.SetIgnoreBreakpoints(true); 351 options.SetStopOthers(true); 352 options.SetTimeout(std::chrono::milliseconds(500)); 353 options.SetTryAllThreads(false); 354 options.SetIsForUtilityExpr(true); 355 thread.CalculateExecutionContext(exe_ctx); 356 357 if (!m_get_thread_item_info_impl_code) { 358 error.SetErrorString("Unable to compile function to call " 359 "__introspection_dispatch_thread_get_item_info"); 360 return return_value; 361 } 362 363 get_thread_item_info_caller = 364 m_get_thread_item_info_impl_code->GetFunctionCaller(); 365 366 if (!get_thread_item_info_caller) { 367 error.SetErrorString("Unable to compile function caller for " 368 "__introspection_dispatch_thread_get_item_info"); 369 return return_value; 370 } 371 372 ExpressionResults func_call_ret; 373 Value results; 374 func_call_ret = get_thread_item_info_caller->ExecuteFunction( 375 exe_ctx, &args_addr, options, diagnostics, results); 376 if (func_call_ret != eExpressionCompleted || !error.Success()) { 377 if (log) 378 log->Printf("Unable to call " 379 "__introspection_dispatch_thread_get_item_info(), got " 380 "ExpressionResults %d, error contains %s", 381 func_call_ret, error.AsCString("")); 382 error.SetErrorString("Unable to call " 383 "__introspection_dispatch_thread_get_item_info() for " 384 "list of queues"); 385 return return_value; 386 } 387 388 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 389 m_get_thread_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, 390 error); 391 if (!error.Success() || 392 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { 393 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 394 return return_value; 395 } 396 397 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 398 m_get_thread_item_info_return_buffer_addr + 8, 8, 0, error); 399 400 if (!error.Success()) { 401 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 402 return return_value; 403 } 404 405 if (log) 406 log->Printf("AppleGetThreadItemInfoHandler called " 407 "__introspection_dispatch_thread_get_item_info (page_to_free " 408 "== 0x%" PRIx64 ", size = %" PRId64 409 "), returned page is at 0x%" PRIx64 ", size %" PRId64, 410 page_to_free, page_to_free_size, return_value.item_buffer_ptr, 411 return_value.item_buffer_size); 412 413 return return_value; 414 } 415