1 //===-- AppleGetPendingItemsHandler.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 "AppleGetPendingItemsHandler.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/FunctionCaller.h" 22 #include "lldb/Expression/UtilityFunction.h" 23 #include "lldb/Symbol/ClangASTContext.h" 24 #include "lldb/Symbol/Symbol.h" 25 #include "lldb/Target/ExecutionContext.h" 26 #include "lldb/Target/Process.h" 27 #include "lldb/Target/Target.h" 28 #include "lldb/Target/Thread.h" 29 #include "lldb/Utility/ConstString.h" 30 #include "lldb/Utility/Log.h" 31 #include "lldb/Utility/StreamString.h" 32 33 using namespace lldb; 34 using namespace lldb_private; 35 36 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_name = 37 "__lldb_backtrace_recording_get_pending_items"; 38 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_code = 39 " \n\ 40 extern \"C\" \n\ 41 { \n\ 42 /* \n\ 43 * mach defines \n\ 44 */ \n\ 45 \n\ 46 typedef unsigned int uint32_t; \n\ 47 typedef unsigned long long uint64_t; \n\ 48 typedef uint32_t mach_port_t; \n\ 49 typedef mach_port_t vm_map_t; \n\ 50 typedef int kern_return_t; \n\ 51 typedef uint64_t mach_vm_address_t; \n\ 52 typedef uint64_t mach_vm_size_t; \n\ 53 \n\ 54 mach_port_t mach_task_self (); \n\ 55 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 56 \n\ 57 /* \n\ 58 * libBacktraceRecording defines \n\ 59 */ \n\ 60 \n\ 61 typedef uint32_t queue_list_scope_t; \n\ 62 typedef void *dispatch_queue_t; \n\ 63 typedef void *introspection_dispatch_queue_info_t; \n\ 64 typedef void *introspection_dispatch_item_info_ref; \n\ 65 \n\ 66 extern uint64_t __introspection_dispatch_queue_get_pending_items (dispatch_queue_t queue, \n\ 67 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 68 uint64_t *returned_queues_buffer_size); \n\ 69 extern int printf(const char *format, ...); \n\ 70 \n\ 71 /* \n\ 72 * return type define \n\ 73 */ \n\ 74 \n\ 75 struct get_pending_items_return_values \n\ 76 { \n\ 77 uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 78 uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 79 uint64_t count; /* the number of items included in the queues buffer */ \n\ 80 }; \n\ 81 \n\ 82 void __lldb_backtrace_recording_get_pending_items \n\ 83 (struct get_pending_items_return_values *return_buffer, \n\ 84 int debug, \n\ 85 uint64_t /* dispatch_queue_t */ queue, \n\ 86 void *page_to_free, \n\ 87 uint64_t page_to_free_size) \n\ 88 { \n\ 89 if (debug) \n\ 90 printf (\"entering get_pending_items with args return_buffer == %p, debug == %d, queue == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, queue, page_to_free, page_to_free_size); \n\ 91 if (page_to_free != 0) \n\ 92 { \n\ 93 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 94 } \n\ 95 \n\ 96 return_buffer->count = __introspection_dispatch_queue_get_pending_items ( \n\ 97 (void*) queue, \n\ 98 (void**)&return_buffer->pending_items_buffer_ptr, \n\ 99 &return_buffer->pending_items_buffer_size); \n\ 100 if (debug) \n\ 101 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 102 } \n\ 103 } \n\ 104 "; 105 106 AppleGetPendingItemsHandler::AppleGetPendingItemsHandler(Process *process) 107 : m_process(process), m_get_pending_items_impl_code(), 108 m_get_pending_items_function_mutex(), 109 m_get_pending_items_return_buffer_addr(LLDB_INVALID_ADDRESS), 110 m_get_pending_items_retbuffer_mutex() {} 111 112 AppleGetPendingItemsHandler::~AppleGetPendingItemsHandler() {} 113 114 void AppleGetPendingItemsHandler::Detach() { 115 if (m_process && m_process->IsAlive() && 116 m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) { 117 std::unique_lock<std::mutex> lock(m_get_pending_items_retbuffer_mutex, 118 std::defer_lock); 119 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 120 m_process->DeallocateMemory(m_get_pending_items_return_buffer_addr); 121 } 122 } 123 124 // Compile our __lldb_backtrace_recording_get_pending_items() function (from 125 // the source above in g_get_pending_items_function_code) if we don't find that 126 // function in the inferior already with USE_BUILTIN_FUNCTION defined. (e.g. 127 // this would be the case for testing.) 128 // 129 // Insert the __lldb_backtrace_recording_get_pending_items into the inferior 130 // process if needed. 131 // 132 // Write the get_pending_items_arglist into the inferior's memory space to 133 // prepare for the call. 134 // 135 // Returns the address of the arguments written down in the inferior process, 136 // which can be used to make the function call. 137 138 lldb::addr_t AppleGetPendingItemsHandler::SetupGetPendingItemsFunction( 139 Thread &thread, ValueList &get_pending_items_arglist) { 140 ThreadSP thread_sp(thread.shared_from_this()); 141 ExecutionContext exe_ctx(thread_sp); 142 DiagnosticManager diagnostics; 143 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 144 145 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 146 FunctionCaller *get_pending_items_caller = nullptr; 147 148 // Scope for mutex locker: 149 { 150 std::lock_guard<std::mutex> guard(m_get_pending_items_function_mutex); 151 152 // First stage is to make the ClangUtility to hold our injected function: 153 154 if (!m_get_pending_items_impl_code.get()) { 155 if (g_get_pending_items_function_code != NULL) { 156 Status error; 157 m_get_pending_items_impl_code.reset( 158 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 159 g_get_pending_items_function_code, eLanguageTypeObjC, 160 g_get_pending_items_function_name, error)); 161 if (error.Fail()) { 162 if (log) 163 log->Printf("Failed to get UtilityFunction for pending-items " 164 "introspection: %s.", 165 error.AsCString()); 166 return args_addr; 167 } 168 169 if (!m_get_pending_items_impl_code->Install(diagnostics, exe_ctx)) { 170 if (log) { 171 log->Printf("Failed to install pending-items introspection."); 172 diagnostics.Dump(log); 173 } 174 m_get_pending_items_impl_code.reset(); 175 return args_addr; 176 } 177 } else { 178 if (log) 179 log->Printf("No pending-items introspection code found."); 180 return LLDB_INVALID_ADDRESS; 181 } 182 183 // Next make the runner function for our implementation utility function. 184 Status error; 185 ClangASTContext *clang_ast_context = 186 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 187 CompilerType get_pending_items_return_type = 188 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 189 get_pending_items_caller = 190 m_get_pending_items_impl_code->MakeFunctionCaller( 191 get_pending_items_return_type, get_pending_items_arglist, 192 thread_sp, error); 193 if (error.Fail() || get_pending_items_caller == nullptr) { 194 if (log) 195 log->Printf("Failed to install pending-items introspection function " 196 "caller: %s.", 197 error.AsCString()); 198 m_get_pending_items_impl_code.reset(); 199 return args_addr; 200 } 201 } 202 } 203 204 diagnostics.Clear(); 205 206 if (get_pending_items_caller == nullptr) { 207 if (log) 208 log->Printf("Failed to get get_pending_items_caller."); 209 return LLDB_INVALID_ADDRESS; 210 } 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_pending_items_caller->WriteFunctionArguments( 218 exe_ctx, args_addr, get_pending_items_arglist, diagnostics)) { 219 if (log) { 220 log->Printf("Error writing pending-items function arguments."); 221 diagnostics.Dump(log); 222 } 223 224 return args_addr; 225 } 226 227 return args_addr; 228 } 229 230 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 231 AppleGetPendingItemsHandler::GetPendingItems(Thread &thread, addr_t queue, 232 addr_t page_to_free, 233 uint64_t page_to_free_size, 234 Status &error) { 235 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 236 ProcessSP process_sp(thread.CalculateProcess()); 237 TargetSP target_sp(thread.CalculateTarget()); 238 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 239 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 240 241 GetPendingItemsReturnInfo return_value; 242 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 243 return_value.items_buffer_size = 0; 244 return_value.count = 0; 245 246 error.Clear(); 247 248 if (thread.SafeToCallFunctions() == false) { 249 if (log) 250 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 251 thread.GetID()); 252 error.SetErrorString("Not safe to call functions on this thread."); 253 return return_value; 254 } 255 256 // Set up the arguments for a call to 257 258 // struct get_pending_items_return_values 259 // { 260 // uint64_t pending_items_buffer_ptr; /* the address of the items 261 // buffer from libBacktraceRecording */ 262 // uint64_t pending_items_buffer_size; /* the size of the items buffer 263 // from libBacktraceRecording */ 264 // uint64_t count; /* the number of items included in the 265 // queues buffer */ 266 // }; 267 // 268 // void __lldb_backtrace_recording_get_pending_items 269 // (struct 270 // get_pending_items_return_values 271 // *return_buffer, 272 // int debug, 273 // uint64_t /* dispatch_queue_t */ 274 // queue 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 CompilerType clang_uint64_type = 293 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 294 Value queue_value; 295 queue_value.SetValueType(Value::eValueTypeScalar); 296 queue_value.SetCompilerType(clang_uint64_type); 297 298 Value page_to_free_value; 299 page_to_free_value.SetValueType(Value::eValueTypeScalar); 300 page_to_free_value.SetCompilerType(clang_void_ptr_type); 301 302 Value page_to_free_size_value; 303 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 304 page_to_free_size_value.SetCompilerType(clang_uint64_type); 305 306 std::lock_guard<std::mutex> guard(m_get_pending_items_retbuffer_mutex); 307 if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) { 308 addr_t bufaddr = process_sp->AllocateMemory( 309 32, ePermissionsReadable | ePermissionsWritable, error); 310 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 311 if (log) 312 log->Printf("Failed to allocate memory for return buffer for get " 313 "current queues func call"); 314 return return_value; 315 } 316 m_get_pending_items_return_buffer_addr = bufaddr; 317 } 318 319 ValueList argument_values; 320 321 return_buffer_ptr_value.GetScalar() = m_get_pending_items_return_buffer_addr; 322 argument_values.PushValue(return_buffer_ptr_value); 323 324 debug_value.GetScalar() = 0; 325 argument_values.PushValue(debug_value); 326 327 queue_value.GetScalar() = queue; 328 argument_values.PushValue(queue_value); 329 330 if (page_to_free != LLDB_INVALID_ADDRESS) 331 page_to_free_value.GetScalar() = page_to_free; 332 else 333 page_to_free_value.GetScalar() = 0; 334 argument_values.PushValue(page_to_free_value); 335 336 page_to_free_size_value.GetScalar() = page_to_free_size; 337 argument_values.PushValue(page_to_free_size_value); 338 339 addr_t args_addr = SetupGetPendingItemsFunction(thread, argument_values); 340 341 DiagnosticManager diagnostics; 342 ExecutionContext exe_ctx; 343 FunctionCaller *get_pending_items_caller = 344 m_get_pending_items_impl_code->GetFunctionCaller(); 345 346 EvaluateExpressionOptions options; 347 options.SetUnwindOnError(true); 348 options.SetIgnoreBreakpoints(true); 349 options.SetStopOthers(true); 350 options.SetTimeout(std::chrono::milliseconds(500)); 351 options.SetTryAllThreads(false); 352 options.SetIsForUtilityExpr(true); 353 thread.CalculateExecutionContext(exe_ctx); 354 355 if (get_pending_items_caller == NULL) { 356 error.SetErrorString("Unable to compile function to call " 357 "__introspection_dispatch_queue_get_pending_items"); 358 return return_value; 359 } 360 361 ExpressionResults func_call_ret; 362 Value results; 363 func_call_ret = get_pending_items_caller->ExecuteFunction( 364 exe_ctx, &args_addr, options, diagnostics, results); 365 if (func_call_ret != eExpressionCompleted || !error.Success()) { 366 if (log) 367 log->Printf("Unable to call " 368 "__introspection_dispatch_queue_get_pending_items(), got " 369 "ExpressionResults %d, error contains %s", 370 func_call_ret, error.AsCString("")); 371 error.SetErrorString("Unable to call " 372 "__introspection_dispatch_queue_get_pending_items() " 373 "for list of queues"); 374 return return_value; 375 } 376 377 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 378 m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 379 if (!error.Success() || 380 return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) { 381 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 382 return return_value; 383 } 384 385 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 386 m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 387 388 if (!error.Success()) { 389 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 390 return return_value; 391 } 392 393 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 394 m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 395 if (!error.Success()) { 396 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 397 return return_value; 398 } 399 400 if (log) 401 log->Printf("AppleGetPendingItemsHandler called " 402 "__introspection_dispatch_queue_get_pending_items " 403 "(page_to_free == 0x%" PRIx64 ", size = %" PRId64 404 "), returned page is at 0x%" PRIx64 ", size %" PRId64 405 ", count = %" PRId64, 406 page_to_free, page_to_free_size, return_value.items_buffer_ptr, 407 return_value.items_buffer_size, return_value.count); 408 409 return return_value; 410 } 411