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 "lldb/Core/Module.h" 17 #include "lldb/Core/Value.h" 18 #include "lldb/Expression/DiagnosticManager.h" 19 #include "lldb/Expression/FunctionCaller.h" 20 #include "lldb/Expression/UtilityFunction.h" 21 #include "lldb/Symbol/ClangASTContext.h" 22 #include "lldb/Symbol/Symbol.h" 23 #include "lldb/Target/ExecutionContext.h" 24 #include "lldb/Target/Process.h" 25 #include "lldb/Target/Target.h" 26 #include "lldb/Target/Thread.h" 27 #include "lldb/Utility/ConstString.h" 28 #include "lldb/Utility/Log.h" 29 #include "lldb/Utility/StreamString.h" 30 31 using namespace lldb; 32 using namespace lldb_private; 33 34 const char *AppleGetQueuesHandler::g_get_current_queues_function_name = 35 "__lldb_backtrace_recording_get_current_queues"; 36 const char *AppleGetQueuesHandler::g_get_current_queues_function_code = 37 " \n\ 38 extern \"C\" \n\ 39 { \n\ 40 /* \n\ 41 * mach defines \n\ 42 */ \n\ 43 \n\ 44 typedef unsigned int uint32_t; \n\ 45 typedef unsigned long long uint64_t; \n\ 46 typedef uint32_t mach_port_t; \n\ 47 typedef mach_port_t vm_map_t; \n\ 48 typedef int kern_return_t; \n\ 49 typedef uint64_t mach_vm_address_t; \n\ 50 typedef uint64_t mach_vm_size_t; \n\ 51 \n\ 52 mach_port_t mach_task_self (); \n\ 53 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 54 \n\ 55 /* \n\ 56 * libBacktraceRecording defines \n\ 57 */ \n\ 58 \n\ 59 typedef uint32_t queue_list_scope_t; \n\ 60 typedef void *introspection_dispatch_queue_info_t; \n\ 61 \n\ 62 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ 63 introspection_dispatch_queue_info_t *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_current_queues_return_values \n\ 72 { \n\ 73 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ 74 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ 75 uint64_t count; /* the number of queues included in the queues buffer */ \n\ 76 }; \n\ 77 \n\ 78 void __lldb_backtrace_recording_get_current_queues \n\ 79 (struct get_current_queues_return_values *return_buffer, \n\ 80 int debug, \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_current_queues with args %p, %d, 0x%p, 0x%llx\\n\", return_buffer, debug, 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 return_buffer->count = __introspection_dispatch_get_queues ( \n\ 92 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ 93 (void**)&return_buffer->queues_buffer_ptr, \n\ 94 &return_buffer->queues_buffer_size); \n\ 95 if (debug) \n\ 96 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 97 } \n\ 98 } \n\ 99 "; 100 101 AppleGetQueuesHandler::AppleGetQueuesHandler(Process *process) 102 : m_process(process), m_get_queues_impl_code_up(), 103 m_get_queues_function_mutex(), 104 m_get_queues_return_buffer_addr(LLDB_INVALID_ADDRESS), 105 m_get_queues_retbuffer_mutex() {} 106 107 AppleGetQueuesHandler::~AppleGetQueuesHandler() {} 108 109 void AppleGetQueuesHandler::Detach() { 110 111 if (m_process && m_process->IsAlive() && 112 m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) { 113 std::unique_lock<std::mutex> lock(m_get_queues_retbuffer_mutex, 114 std::defer_lock); 115 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 116 m_process->DeallocateMemory(m_get_queues_return_buffer_addr); 117 } 118 } 119 120 // Construct a CompilerType for the structure that 121 // g_get_current_queues_function_code will return by value so we can extract 122 // the fields after performing the function call. i.e. we are getting this 123 // struct returned to us: 124 // 125 // struct get_current_queues_return_values 126 // { 127 // introspection_dispatch_queue_info_t *queues_buffer; 128 // uint64_t queues_buffer_size; 129 // uint64_t count; 130 // }; 131 132 // Compile our __lldb_backtrace_recording_get_current_queues() function (from 133 // the source above in g_get_current_queues_function_code) if we don't find 134 // that function in the inferior already with USE_BUILTIN_FUNCTION defined. 135 // (e.g. this would be the case for testing.) 136 // 137 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior 138 // process if needed. 139 // 140 // Write the get_queues_arglist into the inferior's memory space to prepare for 141 // the call. 142 // 143 // Returns the address of the arguments written down in the inferior process, 144 // which can be used to make the function call. 145 146 lldb::addr_t 147 AppleGetQueuesHandler::SetupGetQueuesFunction(Thread &thread, 148 ValueList &get_queues_arglist) { 149 ThreadSP thread_sp(thread.shared_from_this()); 150 ExecutionContext exe_ctx(thread_sp); 151 152 Address impl_code_address; 153 DiagnosticManager diagnostics; 154 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 155 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 156 157 FunctionCaller *get_queues_caller = nullptr; 158 159 // Scope for mutex locker: 160 { 161 std::lock_guard<std::mutex> guard(m_get_queues_function_mutex); 162 163 // First stage is to make the ClangUtility to hold our injected function: 164 165 if (!m_get_queues_impl_code_up.get()) { 166 if (g_get_current_queues_function_code != NULL) { 167 Status error; 168 m_get_queues_impl_code_up.reset( 169 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 170 g_get_current_queues_function_code, eLanguageTypeC, 171 g_get_current_queues_function_name, error)); 172 if (error.Fail()) { 173 if (log) 174 log->Printf( 175 "Failed to get UtilityFunction for queues introspection: %s.", 176 error.AsCString()); 177 return args_addr; 178 } 179 180 if (!m_get_queues_impl_code_up->Install(diagnostics, exe_ctx)) { 181 if (log) { 182 log->Printf("Failed to install queues introspection"); 183 diagnostics.Dump(log); 184 } 185 m_get_queues_impl_code_up.reset(); 186 return args_addr; 187 } 188 } else { 189 if (log) { 190 log->Printf("No queues introspection code found."); 191 diagnostics.Dump(log); 192 } 193 return LLDB_INVALID_ADDRESS; 194 } 195 } 196 197 // Next make the runner function for our implementation utility function. 198 ClangASTContext *clang_ast_context = 199 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 200 CompilerType get_queues_return_type = 201 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 202 Status error; 203 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller( 204 get_queues_return_type, get_queues_arglist, thread_sp, error); 205 if (error.Fail() || get_queues_caller == nullptr) { 206 if (log) 207 log->Printf( 208 "Could not get function caller for get-queues function: %s.", 209 error.AsCString()); 210 return args_addr; 211 } 212 } 213 214 diagnostics.Clear(); 215 216 // Now write down the argument values for this particular call. This looks 217 // like it might be a race condition if other threads were calling into here, 218 // but actually it isn't because we allocate a new args structure for this 219 // call by passing args_addr = LLDB_INVALID_ADDRESS... 220 221 if (!get_queues_caller->WriteFunctionArguments( 222 exe_ctx, args_addr, get_queues_arglist, diagnostics)) { 223 if (log) { 224 log->Printf("Error writing get-queues function arguments."); 225 diagnostics.Dump(log); 226 } 227 return args_addr; 228 } 229 230 return args_addr; 231 } 232 233 AppleGetQueuesHandler::GetQueuesReturnInfo 234 AppleGetQueuesHandler::GetCurrentQueues(Thread &thread, addr_t page_to_free, 235 uint64_t page_to_free_size, 236 Status &error) { 237 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 238 ProcessSP process_sp(thread.CalculateProcess()); 239 TargetSP target_sp(thread.CalculateTarget()); 240 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 241 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 242 243 GetQueuesReturnInfo return_value; 244 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 245 return_value.queues_buffer_size = 0; 246 return_value.count = 0; 247 248 error.Clear(); 249 250 if (thread.SafeToCallFunctions() == false) { 251 if (log) 252 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 253 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_current_queues_return_values 261 // { 262 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from 263 // libBacktraceRecording */ 264 // uint64_t queues_buffer_size; /* the size of the queues buffer from 265 // libBacktraceRecording */ 266 // uint64_t count; /* the number of queues included in the 267 // queues buffer */ 268 // }; 269 // 270 // void 271 // __lldb_backtrace_recording_get_current_queues 272 // (struct 273 // get_current_queues_return_values 274 // *return_buffer, 275 // void *page_to_free, 276 // uint64_t page_to_free_size); 277 278 // Where the return_buffer argument points to a 24 byte region of memory 279 // already allocated by lldb in the inferior process. 280 281 CompilerType clang_void_ptr_type = 282 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 283 Value return_buffer_ptr_value; 284 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 285 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 286 287 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 288 Value debug_value; 289 debug_value.SetValueType(Value::eValueTypeScalar); 290 debug_value.SetCompilerType(clang_int_type); 291 292 Value page_to_free_value; 293 page_to_free_value.SetValueType(Value::eValueTypeScalar); 294 page_to_free_value.SetCompilerType(clang_void_ptr_type); 295 296 CompilerType clang_uint64_type = 297 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 298 Value page_to_free_size_value; 299 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 300 page_to_free_size_value.SetCompilerType(clang_uint64_type); 301 302 std::lock_guard<std::mutex> guard(m_get_queues_retbuffer_mutex); 303 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) { 304 addr_t bufaddr = process_sp->AllocateMemory( 305 32, ePermissionsReadable | ePermissionsWritable, error); 306 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 307 if (log) 308 log->Printf("Failed to allocate memory for return buffer for get " 309 "current queues func call"); 310 return return_value; 311 } 312 m_get_queues_return_buffer_addr = bufaddr; 313 } 314 315 ValueList argument_values; 316 317 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 318 argument_values.PushValue(return_buffer_ptr_value); 319 320 debug_value.GetScalar() = 0; 321 argument_values.PushValue(debug_value); 322 323 if (page_to_free != LLDB_INVALID_ADDRESS) 324 page_to_free_value.GetScalar() = page_to_free; 325 else 326 page_to_free_value.GetScalar() = 0; 327 argument_values.PushValue(page_to_free_value); 328 329 page_to_free_size_value.GetScalar() = page_to_free_size; 330 argument_values.PushValue(page_to_free_size_value); 331 332 addr_t args_addr = SetupGetQueuesFunction(thread, argument_values); 333 334 if (!m_get_queues_impl_code_up) { 335 error.SetErrorString( 336 "Unable to compile __introspection_dispatch_get_queues."); 337 return return_value; 338 } 339 340 FunctionCaller *get_queues_caller = 341 m_get_queues_impl_code_up->GetFunctionCaller(); 342 343 if (get_queues_caller == NULL) { 344 error.SetErrorString( 345 "Unable to get caller for call __introspection_dispatch_get_queues"); 346 return return_value; 347 } 348 349 DiagnosticManager diagnostics; 350 ExecutionContext exe_ctx; 351 EvaluateExpressionOptions options; 352 options.SetUnwindOnError(true); 353 options.SetIgnoreBreakpoints(true); 354 options.SetStopOthers(true); 355 options.SetTimeout(std::chrono::milliseconds(500)); 356 options.SetTryAllThreads(false); 357 options.SetIsForUtilityExpr(true); 358 thread.CalculateExecutionContext(exe_ctx); 359 360 ExpressionResults func_call_ret; 361 Value results; 362 func_call_ret = get_queues_caller->ExecuteFunction( 363 exe_ctx, &args_addr, options, diagnostics, results); 364 if (func_call_ret != eExpressionCompleted || !error.Success()) { 365 if (log) 366 log->Printf("Unable to call introspection_get_dispatch_queues(), got " 367 "ExpressionResults %d, error contains %s", 368 func_call_ret, error.AsCString("")); 369 error.SetErrorString("Unable to call introspection_get_dispatch_queues() " 370 "for list of queues"); 371 return return_value; 372 } 373 374 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 375 m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 376 if (!error.Success() || 377 return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) { 378 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 379 return return_value; 380 } 381 382 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 383 m_get_queues_return_buffer_addr + 8, 8, 0, error); 384 385 if (!error.Success()) { 386 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 387 return return_value; 388 } 389 390 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 391 m_get_queues_return_buffer_addr + 16, 8, 0, error); 392 if (!error.Success()) { 393 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 394 return return_value; 395 } 396 397 if (log) 398 log->Printf("AppleGetQueuesHandler called " 399 "__introspection_dispatch_get_queues (page_to_free == " 400 "0x%" PRIx64 ", size = %" PRId64 401 "), returned page is at 0x%" PRIx64 ", size %" PRId64 402 ", count = %" PRId64, 403 page_to_free, page_to_free_size, return_value.queues_buffer_ptr, 404 return_value.queues_buffer_size, return_value.count); 405 406 return return_value; 407 } 408