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 #include "lldb/Core/Module.h" 13 #include "lldb/Core/Value.h" 14 #include "lldb/Expression/DiagnosticManager.h" 15 #include "lldb/Expression/FunctionCaller.h" 16 #include "lldb/Expression/UtilityFunction.h" 17 #include "lldb/Symbol/ClangASTContext.h" 18 #include "lldb/Symbol/Symbol.h" 19 #include "lldb/Target/ExecutionContext.h" 20 #include "lldb/Target/Process.h" 21 #include "lldb/Target/Target.h" 22 #include "lldb/Target/Thread.h" 23 #include "lldb/Utility/ConstString.h" 24 #include "lldb/Utility/Log.h" 25 #include "lldb/Utility/StreamString.h" 26 27 using namespace lldb; 28 using namespace lldb_private; 29 30 const char *AppleGetQueuesHandler::g_get_current_queues_function_name = 31 "__lldb_backtrace_recording_get_current_queues"; 32 const char *AppleGetQueuesHandler::g_get_current_queues_function_code = 33 " \n\ 34 extern \"C\" \n\ 35 { \n\ 36 /* \n\ 37 * mach defines \n\ 38 */ \n\ 39 \n\ 40 typedef unsigned int uint32_t; \n\ 41 typedef unsigned long long uint64_t; \n\ 42 typedef uint32_t mach_port_t; \n\ 43 typedef mach_port_t vm_map_t; \n\ 44 typedef int kern_return_t; \n\ 45 typedef uint64_t mach_vm_address_t; \n\ 46 typedef uint64_t mach_vm_size_t; \n\ 47 \n\ 48 mach_port_t mach_task_self (); \n\ 49 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 50 \n\ 51 /* \n\ 52 * libBacktraceRecording defines \n\ 53 */ \n\ 54 \n\ 55 typedef uint32_t queue_list_scope_t; \n\ 56 typedef void *introspection_dispatch_queue_info_t; \n\ 57 \n\ 58 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ 59 introspection_dispatch_queue_info_t *returned_queues_buffer, \n\ 60 uint64_t *returned_queues_buffer_size); \n\ 61 extern int printf(const char *format, ...); \n\ 62 \n\ 63 /* \n\ 64 * return type define \n\ 65 */ \n\ 66 \n\ 67 struct get_current_queues_return_values \n\ 68 { \n\ 69 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ 70 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ 71 uint64_t count; /* the number of queues included in the queues buffer */ \n\ 72 }; \n\ 73 \n\ 74 void __lldb_backtrace_recording_get_current_queues \n\ 75 (struct get_current_queues_return_values *return_buffer, \n\ 76 int debug, \n\ 77 void *page_to_free, \n\ 78 uint64_t page_to_free_size) \n\ 79 { \n\ 80 if (debug) \n\ 81 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\ 82 if (page_to_free != 0) \n\ 83 { \n\ 84 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 85 } \n\ 86 \n\ 87 return_buffer->count = __introspection_dispatch_get_queues ( \n\ 88 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ 89 (void**)&return_buffer->queues_buffer_ptr, \n\ 90 &return_buffer->queues_buffer_size); \n\ 91 if (debug) \n\ 92 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 93 } \n\ 94 } \n\ 95 "; 96 97 AppleGetQueuesHandler::AppleGetQueuesHandler(Process *process) 98 : m_process(process), m_get_queues_impl_code_up(), 99 m_get_queues_function_mutex(), 100 m_get_queues_return_buffer_addr(LLDB_INVALID_ADDRESS), 101 m_get_queues_retbuffer_mutex() {} 102 103 AppleGetQueuesHandler::~AppleGetQueuesHandler() {} 104 105 void AppleGetQueuesHandler::Detach() { 106 107 if (m_process && m_process->IsAlive() && 108 m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) { 109 std::unique_lock<std::mutex> lock(m_get_queues_retbuffer_mutex, 110 std::defer_lock); 111 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 112 m_process->DeallocateMemory(m_get_queues_return_buffer_addr); 113 } 114 } 115 116 // Construct a CompilerType for the structure that 117 // g_get_current_queues_function_code will return by value so we can extract 118 // the fields after performing the function call. i.e. we are getting this 119 // struct returned to us: 120 // 121 // struct get_current_queues_return_values 122 // { 123 // introspection_dispatch_queue_info_t *queues_buffer; 124 // uint64_t queues_buffer_size; 125 // uint64_t count; 126 // }; 127 128 // Compile our __lldb_backtrace_recording_get_current_queues() function (from 129 // the source above in g_get_current_queues_function_code) if we don't find 130 // that function in the inferior already with USE_BUILTIN_FUNCTION defined. 131 // (e.g. this would be the case for testing.) 132 // 133 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior 134 // process if needed. 135 // 136 // Write the get_queues_arglist into the inferior's memory space to prepare for 137 // the call. 138 // 139 // Returns the address of the arguments written down in the inferior process, 140 // which can be used to make the function call. 141 142 lldb::addr_t 143 AppleGetQueuesHandler::SetupGetQueuesFunction(Thread &thread, 144 ValueList &get_queues_arglist) { 145 ThreadSP thread_sp(thread.shared_from_this()); 146 ExecutionContext exe_ctx(thread_sp); 147 148 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; 152 153 FunctionCaller *get_queues_caller = nullptr; 154 155 // Scope for mutex locker: 156 { 157 std::lock_guard<std::mutex> guard(m_get_queues_function_mutex); 158 159 // First stage is to make the ClangUtility to hold our injected function: 160 161 if (!m_get_queues_impl_code_up.get()) { 162 if (g_get_current_queues_function_code != NULL) { 163 Status error; 164 m_get_queues_impl_code_up.reset( 165 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 166 g_get_current_queues_function_code, eLanguageTypeC, 167 g_get_current_queues_function_name, error)); 168 if (error.Fail()) { 169 if (log) 170 log->Printf( 171 "Failed to get UtilityFunction for queues introspection: %s.", 172 error.AsCString()); 173 return args_addr; 174 } 175 176 if (!m_get_queues_impl_code_up->Install(diagnostics, exe_ctx)) { 177 if (log) { 178 log->Printf("Failed to install queues introspection"); 179 diagnostics.Dump(log); 180 } 181 m_get_queues_impl_code_up.reset(); 182 return args_addr; 183 } 184 } else { 185 if (log) { 186 log->Printf("No queues introspection code found."); 187 diagnostics.Dump(log); 188 } 189 return LLDB_INVALID_ADDRESS; 190 } 191 } 192 193 // Next make the runner function for our implementation utility function. 194 ClangASTContext *clang_ast_context = 195 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 196 CompilerType get_queues_return_type = 197 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 198 Status error; 199 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller( 200 get_queues_return_type, get_queues_arglist, thread_sp, error); 201 if (error.Fail() || get_queues_caller == nullptr) { 202 if (log) 203 log->Printf( 204 "Could not get function caller for get-queues function: %s.", 205 error.AsCString()); 206 return args_addr; 207 } 208 } 209 210 diagnostics.Clear(); 211 212 // Now write down the argument values for this particular call. This looks 213 // like it might be a race condition if other threads were calling into here, 214 // but actually it isn't because we allocate a new args structure for this 215 // call by passing args_addr = LLDB_INVALID_ADDRESS... 216 217 if (!get_queues_caller->WriteFunctionArguments( 218 exe_ctx, args_addr, get_queues_arglist, diagnostics)) { 219 if (log) { 220 log->Printf("Error writing get-queues function arguments."); 221 diagnostics.Dump(log); 222 } 223 return args_addr; 224 } 225 226 return args_addr; 227 } 228 229 AppleGetQueuesHandler::GetQueuesReturnInfo 230 AppleGetQueuesHandler::GetCurrentQueues(Thread &thread, addr_t page_to_free, 231 uint64_t page_to_free_size, 232 Status &error) { 233 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 234 ProcessSP process_sp(thread.CalculateProcess()); 235 TargetSP target_sp(thread.CalculateTarget()); 236 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 237 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 238 239 GetQueuesReturnInfo return_value; 240 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 241 return_value.queues_buffer_size = 0; 242 return_value.count = 0; 243 244 error.Clear(); 245 246 if (!thread.SafeToCallFunctions()) { 247 if (log) 248 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 249 thread.GetID()); 250 error.SetErrorString("Not safe to call functions on this thread."); 251 return return_value; 252 } 253 254 // Set up the arguments for a call to 255 256 // struct get_current_queues_return_values 257 // { 258 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from 259 // libBacktraceRecording */ 260 // uint64_t queues_buffer_size; /* the size of the queues buffer from 261 // libBacktraceRecording */ 262 // uint64_t count; /* the number of queues included in the 263 // queues buffer */ 264 // }; 265 // 266 // void 267 // __lldb_backtrace_recording_get_current_queues 268 // (struct 269 // get_current_queues_return_values 270 // *return_buffer, 271 // void *page_to_free, 272 // uint64_t page_to_free_size); 273 274 // Where the return_buffer argument points to a 24 byte region of memory 275 // already allocated by lldb in the inferior process. 276 277 CompilerType clang_void_ptr_type = 278 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 279 Value return_buffer_ptr_value; 280 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 281 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 282 283 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 284 Value debug_value; 285 debug_value.SetValueType(Value::eValueTypeScalar); 286 debug_value.SetCompilerType(clang_int_type); 287 288 Value page_to_free_value; 289 page_to_free_value.SetValueType(Value::eValueTypeScalar); 290 page_to_free_value.SetCompilerType(clang_void_ptr_type); 291 292 CompilerType clang_uint64_type = 293 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 294 Value page_to_free_size_value; 295 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 296 page_to_free_size_value.SetCompilerType(clang_uint64_type); 297 298 std::lock_guard<std::mutex> guard(m_get_queues_retbuffer_mutex); 299 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) { 300 addr_t bufaddr = process_sp->AllocateMemory( 301 32, ePermissionsReadable | ePermissionsWritable, error); 302 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 303 if (log) 304 log->Printf("Failed to allocate memory for return buffer for get " 305 "current queues func call"); 306 return return_value; 307 } 308 m_get_queues_return_buffer_addr = bufaddr; 309 } 310 311 ValueList argument_values; 312 313 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 314 argument_values.PushValue(return_buffer_ptr_value); 315 316 debug_value.GetScalar() = 0; 317 argument_values.PushValue(debug_value); 318 319 if (page_to_free != LLDB_INVALID_ADDRESS) 320 page_to_free_value.GetScalar() = page_to_free; 321 else 322 page_to_free_value.GetScalar() = 0; 323 argument_values.PushValue(page_to_free_value); 324 325 page_to_free_size_value.GetScalar() = page_to_free_size; 326 argument_values.PushValue(page_to_free_size_value); 327 328 addr_t args_addr = SetupGetQueuesFunction(thread, argument_values); 329 330 if (!m_get_queues_impl_code_up) { 331 error.SetErrorString( 332 "Unable to compile __introspection_dispatch_get_queues."); 333 return return_value; 334 } 335 336 FunctionCaller *get_queues_caller = 337 m_get_queues_impl_code_up->GetFunctionCaller(); 338 339 if (get_queues_caller == NULL) { 340 error.SetErrorString( 341 "Unable to get caller for call __introspection_dispatch_get_queues"); 342 return return_value; 343 } 344 345 DiagnosticManager diagnostics; 346 ExecutionContext exe_ctx; 347 EvaluateExpressionOptions options; 348 options.SetUnwindOnError(true); 349 options.SetIgnoreBreakpoints(true); 350 options.SetStopOthers(true); 351 options.SetTimeout(std::chrono::milliseconds(500)); 352 options.SetTryAllThreads(false); 353 options.SetIsForUtilityExpr(true); 354 thread.CalculateExecutionContext(exe_ctx); 355 356 ExpressionResults func_call_ret; 357 Value results; 358 func_call_ret = get_queues_caller->ExecuteFunction( 359 exe_ctx, &args_addr, options, diagnostics, results); 360 if (func_call_ret != eExpressionCompleted || !error.Success()) { 361 if (log) 362 log->Printf("Unable to call introspection_get_dispatch_queues(), got " 363 "ExpressionResults %d, error contains %s", 364 func_call_ret, error.AsCString("")); 365 error.SetErrorString("Unable to call introspection_get_dispatch_queues() " 366 "for list of queues"); 367 return return_value; 368 } 369 370 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 371 m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 372 if (!error.Success() || 373 return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) { 374 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 375 return return_value; 376 } 377 378 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 379 m_get_queues_return_buffer_addr + 8, 8, 0, error); 380 381 if (!error.Success()) { 382 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 383 return return_value; 384 } 385 386 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 387 m_get_queues_return_buffer_addr + 16, 8, 0, error); 388 if (!error.Success()) { 389 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 390 return return_value; 391 } 392 393 if (log) 394 log->Printf("AppleGetQueuesHandler called " 395 "__introspection_dispatch_get_queues (page_to_free == " 396 "0x%" PRIx64 ", size = %" PRId64 397 "), returned page is at 0x%" PRIx64 ", size %" PRId64 398 ", count = %" PRId64, 399 page_to_free, page_to_free_size, return_value.queues_buffer_ptr, 400 return_value.queues_buffer_size, return_value.count); 401 402 return return_value; 403 } 404