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 = "__lldb_backtrace_recording_get_current_queues"; 35 const char *AppleGetQueuesHandler::g_get_current_queues_function_code = " \n\ 36 extern \"C\" \n\ 37 { \n\ 38 /* \n\ 39 * mach defines \n\ 40 */ \n\ 41 \n\ 42 typedef unsigned int uint32_t; \n\ 43 typedef unsigned long long uint64_t; \n\ 44 typedef uint32_t mach_port_t; \n\ 45 typedef mach_port_t vm_map_t; \n\ 46 typedef int kern_return_t; \n\ 47 typedef uint64_t mach_vm_address_t; \n\ 48 typedef uint64_t mach_vm_size_t; \n\ 49 \n\ 50 mach_port_t mach_task_self (); \n\ 51 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 52 \n\ 53 /* \n\ 54 * libBacktraceRecording defines \n\ 55 */ \n\ 56 \n\ 57 typedef uint32_t queue_list_scope_t; \n\ 58 typedef void *introspection_dispatch_queue_info_t; \n\ 59 \n\ 60 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ 61 introspection_dispatch_queue_info_t *returned_queues_buffer, \n\ 62 uint64_t *returned_queues_buffer_size); \n\ 63 extern int printf(const char *format, ...); \n\ 64 \n\ 65 /* \n\ 66 * return type define \n\ 67 */ \n\ 68 \n\ 69 struct get_current_queues_return_values \n\ 70 { \n\ 71 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ 72 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ 73 uint64_t count; /* the number of queues included in the queues buffer */ \n\ 74 }; \n\ 75 \n\ 76 void __lldb_backtrace_recording_get_current_queues \n\ 77 (struct get_current_queues_return_values *return_buffer, \n\ 78 int debug, \n\ 79 void *page_to_free, \n\ 80 uint64_t page_to_free_size) \n\ 81 { \n\ 82 if (debug) \n\ 83 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\ 84 if (page_to_free != 0) \n\ 85 { \n\ 86 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 87 } \n\ 88 \n\ 89 return_buffer->count = __introspection_dispatch_get_queues ( \n\ 90 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ 91 (void**)&return_buffer->queues_buffer_ptr, \n\ 92 &return_buffer->queues_buffer_size); \n\ 93 if (debug) \n\ 94 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 95 } \n\ 96 } \n\ 97 "; 98 99 AppleGetQueuesHandler::AppleGetQueuesHandler (Process *process) : 100 m_process (process), 101 m_get_queues_impl_code_up (), 102 m_get_queues_function_mutex(), 103 m_get_queues_return_buffer_addr (LLDB_INVALID_ADDRESS), 104 m_get_queues_retbuffer_mutex() 105 { 106 } 107 108 AppleGetQueuesHandler::~AppleGetQueuesHandler () 109 { 110 } 111 112 void 113 AppleGetQueuesHandler::Detach () 114 { 115 116 if (m_process && m_process->IsAlive() && m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) 117 { 118 Mutex::Locker locker; 119 locker.TryLock (m_get_queues_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 120 m_process->DeallocateMemory (m_get_queues_return_buffer_addr); 121 } 122 } 123 124 // Construct a CompilerType for the structure that g_get_current_queues_function_code will return by value 125 // so we can extract the fields after performing the function call. 126 // i.e. we are getting this struct returned to us: 127 // 128 // struct get_current_queues_return_values 129 // { 130 // introspection_dispatch_queue_info_t *queues_buffer; 131 // uint64_t queues_buffer_size; 132 // uint64_t count; 133 // }; 134 135 136 // Compile our __lldb_backtrace_recording_get_current_queues() function (from the 137 // source above in g_get_current_queues_function_code) if we don't find that function in the inferior 138 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 139 // 140 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior process if needed. 141 // 142 // Write the get_queues_arglist into the inferior's memory space to prepare for the call. 143 // 144 // Returns the address of the arguments written down in the inferior process, which can be used to 145 // make the function call. 146 147 lldb::addr_t 148 AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_queues_arglist) 149 { 150 ThreadSP thread_sp(thread.shared_from_this()); 151 ExecutionContext exe_ctx (thread_sp); 152 153 Address impl_code_address; 154 DiagnosticManager diagnostics; 155 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 156 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 157 158 FunctionCaller *get_queues_caller = nullptr; 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 if (!m_get_queues_impl_code_up.get()) 167 { 168 if (g_get_current_queues_function_code != NULL) 169 { 170 Error error; 171 m_get_queues_impl_code_up.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_current_queues_function_code, 172 eLanguageTypeC, 173 g_get_current_queues_function_name, 174 error)); 175 if (error.Fail()) 176 { 177 if (log) 178 log->Printf ("Failed to get UtilityFunction for queues introspection: %s.", error.AsCString()); 179 return args_addr; 180 } 181 182 if (!m_get_queues_impl_code_up->Install(diagnostics, exe_ctx)) 183 { 184 if (log) 185 { 186 log->Printf("Failed to install queues introspection"); 187 diagnostics.Dump(log); 188 } 189 m_get_queues_impl_code_up.reset(); 190 return args_addr; 191 } 192 } 193 else 194 { 195 if (log) 196 { 197 log->Printf("No queues introspection code found."); 198 diagnostics.Dump(log); 199 } 200 return LLDB_INVALID_ADDRESS; 201 } 202 } 203 204 // Next make the runner function for our implementation utility function. 205 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 206 CompilerType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 207 Error error; 208 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller (get_queues_return_type, 209 get_queues_arglist, 210 thread_sp, 211 error); 212 if (error.Fail()) 213 { 214 if (log) 215 log->Printf ("Could not get function caller for get-queues function: %s.", error.AsCString()); 216 return args_addr; 217 } 218 } 219 220 diagnostics.Clear(); 221 222 // Now write down the argument values for this particular call. This looks like it might be a race condition 223 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 224 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 225 226 if (!get_queues_caller->WriteFunctionArguments(exe_ctx, args_addr, get_queues_arglist, diagnostics)) 227 { 228 if (log) 229 { 230 log->Printf("Error writing get-queues function arguments."); 231 diagnostics.Dump(log); 232 } 233 return args_addr; 234 } 235 236 return args_addr; 237 } 238 239 AppleGetQueuesHandler::GetQueuesReturnInfo 240 AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 241 { 242 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 243 ProcessSP process_sp (thread.CalculateProcess()); 244 TargetSP target_sp (thread.CalculateTarget()); 245 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 246 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 247 248 GetQueuesReturnInfo return_value; 249 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 250 return_value.queues_buffer_size = 0; 251 return_value.count = 0; 252 253 error.Clear(); 254 255 if (thread.SafeToCallFunctions() == false) 256 { 257 if (log) 258 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, 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_current_queues_return_values 266 // { 267 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ 268 // uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ 269 // uint64_t count; /* the number of queues included in the queues buffer */ 270 // }; 271 // 272 // void 273 // __lldb_backtrace_recording_get_current_queues 274 // (struct get_current_queues_return_values *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 already allocated by lldb in 279 // the inferior process. 280 281 CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 282 Value return_buffer_ptr_value; 283 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 284 return_buffer_ptr_value.SetCompilerType (clang_void_ptr_type); 285 286 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 287 Value debug_value; 288 debug_value.SetValueType (Value::eValueTypeScalar); 289 debug_value.SetCompilerType (clang_int_type); 290 291 Value page_to_free_value; 292 page_to_free_value.SetValueType (Value::eValueTypeScalar); 293 page_to_free_value.SetCompilerType (clang_void_ptr_type); 294 295 CompilerType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 296 Value page_to_free_size_value; 297 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 298 page_to_free_size_value.SetCompilerType (clang_uint64_type); 299 300 301 Mutex::Locker locker(m_get_queues_retbuffer_mutex); 302 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) 303 { 304 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 305 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 306 { 307 if (log) 308 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 309 return return_value; 310 } 311 m_get_queues_return_buffer_addr = bufaddr; 312 } 313 314 ValueList argument_values; 315 316 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 317 argument_values.PushValue (return_buffer_ptr_value); 318 319 debug_value.GetScalar() = 0; 320 argument_values.PushValue (debug_value); 321 322 if (page_to_free != LLDB_INVALID_ADDRESS) 323 page_to_free_value.GetScalar() = page_to_free; 324 else 325 page_to_free_value.GetScalar() = 0; 326 argument_values.PushValue (page_to_free_value); 327 328 page_to_free_size_value.GetScalar() = page_to_free_size; 329 argument_values.PushValue (page_to_free_size_value); 330 331 addr_t args_addr = SetupGetQueuesFunction (thread, argument_values); 332 333 if (!m_get_queues_impl_code_up) 334 { 335 error.SetErrorString ("Unable to compile __introspection_dispatch_get_queues."); 336 return return_value; 337 } 338 339 FunctionCaller *get_queues_caller = m_get_queues_impl_code_up->GetFunctionCaller(); 340 341 if (get_queues_caller == NULL) 342 { 343 error.SetErrorString ("Unable to get caller for call __introspection_dispatch_get_queues"); 344 return return_value; 345 } 346 347 DiagnosticManager diagnostics; 348 ExecutionContext exe_ctx; 349 EvaluateExpressionOptions options; 350 options.SetUnwindOnError(true); 351 options.SetIgnoreBreakpoints (true); 352 options.SetStopOthers (true); 353 options.SetTimeoutUsec(500000); 354 options.SetTryAllThreads (false); 355 thread.CalculateExecutionContext (exe_ctx); 356 357 ExpressionResults func_call_ret; 358 Value results; 359 func_call_ret = get_queues_caller->ExecuteFunction(exe_ctx, &args_addr, options, diagnostics, results); 360 if (func_call_ret != eExpressionCompleted || !error.Success()) 361 { 362 if (log) 363 log->Printf ("Unable to call introspection_get_dispatch_queues(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 364 error.SetErrorString ("Unable to call introspection_get_dispatch_queues() for list of queues"); 365 return return_value; 366 } 367 368 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 369 if (!error.Success() || return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) 370 { 371 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 372 return return_value; 373 } 374 375 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 8, 8, 0, error); 376 377 if (!error.Success()) 378 { 379 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 380 return return_value; 381 } 382 383 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 16, 8, 0, error); 384 if (!error.Success()) 385 { 386 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 387 return return_value; 388 } 389 390 if (log) 391 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); 392 393 return return_value; 394 } 395