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/ConstString.h" 17 #include "lldb/Core/Log.h" 18 #include "lldb/Core/Module.h" 19 #include "lldb/Core/StreamString.h" 20 #include "lldb/Core/Value.h" 21 #include "lldb/Expression/DiagnosticManager.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/Target.h" 29 #include "lldb/Target/Thread.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 122 // so we can extract the fields after performing the function call. 123 // i.e. we are getting this 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 134 // source above in g_get_current_queues_function_code) if we don't find that 135 // function in the inferior 136 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for 137 // testing.) 138 // 139 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior 140 // process if needed. 141 // 142 // Write the get_queues_arglist into the inferior's memory space to prepare for 143 // the call. 144 // 145 // Returns the address of the arguments written down in the inferior process, 146 // which can be used to 147 // make the function call. 148 149 lldb::addr_t 150 AppleGetQueuesHandler::SetupGetQueuesFunction(Thread &thread, 151 ValueList &get_queues_arglist) { 152 ThreadSP thread_sp(thread.shared_from_this()); 153 ExecutionContext exe_ctx(thread_sp); 154 155 Address impl_code_address; 156 DiagnosticManager diagnostics; 157 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 158 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 159 160 FunctionCaller *get_queues_caller = nullptr; 161 162 // Scope for mutex locker: 163 { 164 std::lock_guard<std::mutex> guard(m_get_queues_function_mutex); 165 166 // First stage is to make the ClangUtility to hold our injected function: 167 168 if (!m_get_queues_impl_code_up.get()) { 169 if (g_get_current_queues_function_code != NULL) { 170 Error error; 171 m_get_queues_impl_code_up.reset( 172 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 173 g_get_current_queues_function_code, eLanguageTypeC, 174 g_get_current_queues_function_name, error)); 175 if (error.Fail()) { 176 if (log) 177 log->Printf( 178 "Failed to get UtilityFunction for queues introspection: %s.", 179 error.AsCString()); 180 return args_addr; 181 } 182 183 if (!m_get_queues_impl_code_up->Install(diagnostics, exe_ctx)) { 184 if (log) { 185 log->Printf("Failed to install queues introspection"); 186 diagnostics.Dump(log); 187 } 188 m_get_queues_impl_code_up.reset(); 189 return args_addr; 190 } 191 } else { 192 if (log) { 193 log->Printf("No queues introspection code found."); 194 diagnostics.Dump(log); 195 } 196 return LLDB_INVALID_ADDRESS; 197 } 198 } 199 200 // Next make the runner function for our implementation utility function. 201 ClangASTContext *clang_ast_context = 202 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 203 CompilerType get_queues_return_type = 204 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 205 Error error; 206 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller( 207 get_queues_return_type, get_queues_arglist, thread_sp, error); 208 if (error.Fail()) { 209 if (log) 210 log->Printf( 211 "Could not get function caller for get-queues function: %s.", 212 error.AsCString()); 213 return args_addr; 214 } 215 } 216 217 diagnostics.Clear(); 218 219 // Now write down the argument values for this particular call. This looks 220 // like it might be a race condition 221 // if other threads were calling into here, but actually it isn't because we 222 // allocate a new args structure for 223 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 224 225 if (!get_queues_caller->WriteFunctionArguments( 226 exe_ctx, args_addr, get_queues_arglist, diagnostics)) { 227 if (log) { 228 log->Printf("Error writing get-queues function arguments."); 229 diagnostics.Dump(log); 230 } 231 return args_addr; 232 } 233 234 return args_addr; 235 } 236 237 AppleGetQueuesHandler::GetQueuesReturnInfo 238 AppleGetQueuesHandler::GetCurrentQueues(Thread &thread, addr_t page_to_free, 239 uint64_t page_to_free_size, 240 Error &error) { 241 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 242 ProcessSP process_sp(thread.CalculateProcess()); 243 TargetSP target_sp(thread.CalculateTarget()); 244 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 245 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 246 247 GetQueuesReturnInfo return_value; 248 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 249 return_value.queues_buffer_size = 0; 250 return_value.count = 0; 251 252 error.Clear(); 253 254 if (thread.SafeToCallFunctions() == false) { 255 if (log) 256 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 257 thread.GetID()); 258 error.SetErrorString("Not safe to call functions on this thread."); 259 return return_value; 260 } 261 262 // Set up the arguments for a call to 263 264 // struct get_current_queues_return_values 265 // { 266 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from 267 // libBacktraceRecording */ 268 // uint64_t queues_buffer_size; /* the size of the queues buffer from 269 // libBacktraceRecording */ 270 // uint64_t count; /* the number of queues included in the 271 // queues buffer */ 272 // }; 273 // 274 // void 275 // __lldb_backtrace_recording_get_current_queues 276 // (struct 277 // get_current_queues_return_values 278 // *return_buffer, 279 // void *page_to_free, 280 // uint64_t page_to_free_size); 281 282 // Where the return_buffer argument points to a 24 byte region of memory 283 // already allocated by lldb in 284 // the inferior process. 285 286 CompilerType clang_void_ptr_type = 287 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 288 Value return_buffer_ptr_value; 289 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 290 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 291 292 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 293 Value debug_value; 294 debug_value.SetValueType(Value::eValueTypeScalar); 295 debug_value.SetCompilerType(clang_int_type); 296 297 Value page_to_free_value; 298 page_to_free_value.SetValueType(Value::eValueTypeScalar); 299 page_to_free_value.SetCompilerType(clang_void_ptr_type); 300 301 CompilerType clang_uint64_type = 302 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 303 Value page_to_free_size_value; 304 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 305 page_to_free_size_value.SetCompilerType(clang_uint64_type); 306 307 std::lock_guard<std::mutex> guard(m_get_queues_retbuffer_mutex); 308 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) { 309 addr_t bufaddr = process_sp->AllocateMemory( 310 32, ePermissionsReadable | ePermissionsWritable, error); 311 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 312 if (log) 313 log->Printf("Failed to allocate memory for return buffer for get " 314 "current queues func call"); 315 return return_value; 316 } 317 m_get_queues_return_buffer_addr = bufaddr; 318 } 319 320 ValueList argument_values; 321 322 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 323 argument_values.PushValue(return_buffer_ptr_value); 324 325 debug_value.GetScalar() = 0; 326 argument_values.PushValue(debug_value); 327 328 if (page_to_free != LLDB_INVALID_ADDRESS) 329 page_to_free_value.GetScalar() = page_to_free; 330 else 331 page_to_free_value.GetScalar() = 0; 332 argument_values.PushValue(page_to_free_value); 333 334 page_to_free_size_value.GetScalar() = page_to_free_size; 335 argument_values.PushValue(page_to_free_size_value); 336 337 addr_t args_addr = SetupGetQueuesFunction(thread, argument_values); 338 339 if (!m_get_queues_impl_code_up) { 340 error.SetErrorString( 341 "Unable to compile __introspection_dispatch_get_queues."); 342 return return_value; 343 } 344 345 FunctionCaller *get_queues_caller = 346 m_get_queues_impl_code_up->GetFunctionCaller(); 347 348 if (get_queues_caller == NULL) { 349 error.SetErrorString( 350 "Unable to get caller for call __introspection_dispatch_get_queues"); 351 return return_value; 352 } 353 354 DiagnosticManager diagnostics; 355 ExecutionContext exe_ctx; 356 EvaluateExpressionOptions options; 357 options.SetUnwindOnError(true); 358 options.SetIgnoreBreakpoints(true); 359 options.SetStopOthers(true); 360 options.SetTimeoutUsec(500000); 361 options.SetTryAllThreads(false); 362 thread.CalculateExecutionContext(exe_ctx); 363 364 ExpressionResults func_call_ret; 365 Value results; 366 func_call_ret = get_queues_caller->ExecuteFunction( 367 exe_ctx, &args_addr, options, diagnostics, results); 368 if (func_call_ret != eExpressionCompleted || !error.Success()) { 369 if (log) 370 log->Printf("Unable to call introspection_get_dispatch_queues(), got " 371 "ExpressionResults %d, error contains %s", 372 func_call_ret, error.AsCString("")); 373 error.SetErrorString("Unable to call introspection_get_dispatch_queues() " 374 "for list of queues"); 375 return return_value; 376 } 377 378 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 379 m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 380 if (!error.Success() || 381 return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) { 382 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 383 return return_value; 384 } 385 386 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 387 m_get_queues_return_buffer_addr + 8, 8, 0, error); 388 389 if (!error.Success()) { 390 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 391 return return_value; 392 } 393 394 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 395 m_get_queues_return_buffer_addr + 16, 8, 0, error); 396 if (!error.Success()) { 397 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 398 return return_value; 399 } 400 401 if (log) 402 log->Printf("AppleGetQueuesHandler called " 403 "__introspection_dispatch_get_queues (page_to_free == " 404 "0x%" PRIx64 ", size = %" PRId64 405 "), returned page is at 0x%" PRIx64 ", size %" PRId64 406 ", count = %" PRId64, 407 page_to_free, page_to_free_size, return_value.queues_buffer_ptr, 408 return_value.queues_buffer_size, return_value.count); 409 410 return return_value; 411 } 412