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 14 #include "lldb/Core/Module.h" 15 #include "lldb/Core/Value.h" 16 #include "lldb/Expression/DiagnosticManager.h" 17 #include "lldb/Expression/FunctionCaller.h" 18 #include "lldb/Expression/UtilityFunction.h" 19 #include "lldb/Symbol/ClangASTContext.h" 20 #include "lldb/Symbol/Symbol.h" 21 #include "lldb/Target/ExecutionContext.h" 22 #include "lldb/Target/Process.h" 23 #include "lldb/Target/Target.h" 24 #include "lldb/Target/Thread.h" 25 #include "lldb/Utility/ConstString.h" 26 #include "lldb/Utility/Log.h" 27 #include "lldb/Utility/StreamString.h" 28 29 using namespace lldb; 30 using namespace lldb_private; 31 32 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_name = 33 "__lldb_backtrace_recording_get_pending_items"; 34 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_code = 35 " \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 *dispatch_queue_t; \n\ 59 typedef void *introspection_dispatch_queue_info_t; \n\ 60 typedef void *introspection_dispatch_item_info_ref; \n\ 61 \n\ 62 extern uint64_t __introspection_dispatch_queue_get_pending_items (dispatch_queue_t queue, \n\ 63 introspection_dispatch_item_info_ref *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_pending_items_return_values \n\ 72 { \n\ 73 uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 74 uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 75 uint64_t count; /* the number of items included in the queues buffer */ \n\ 76 }; \n\ 77 \n\ 78 void __lldb_backtrace_recording_get_pending_items \n\ 79 (struct get_pending_items_return_values *return_buffer, \n\ 80 int debug, \n\ 81 uint64_t /* dispatch_queue_t */ queue, \n\ 82 void *page_to_free, \n\ 83 uint64_t page_to_free_size) \n\ 84 { \n\ 85 if (debug) \n\ 86 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\ 87 if (page_to_free != 0) \n\ 88 { \n\ 89 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 90 } \n\ 91 \n\ 92 return_buffer->count = __introspection_dispatch_queue_get_pending_items ( \n\ 93 (void*) queue, \n\ 94 (void**)&return_buffer->pending_items_buffer_ptr, \n\ 95 &return_buffer->pending_items_buffer_size); \n\ 96 if (debug) \n\ 97 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 98 } \n\ 99 } \n\ 100 "; 101 102 AppleGetPendingItemsHandler::AppleGetPendingItemsHandler(Process *process) 103 : m_process(process), m_get_pending_items_impl_code(), 104 m_get_pending_items_function_mutex(), 105 m_get_pending_items_return_buffer_addr(LLDB_INVALID_ADDRESS), 106 m_get_pending_items_retbuffer_mutex() {} 107 108 AppleGetPendingItemsHandler::~AppleGetPendingItemsHandler() {} 109 110 void AppleGetPendingItemsHandler::Detach() { 111 if (m_process && m_process->IsAlive() && 112 m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) { 113 std::unique_lock<std::mutex> lock(m_get_pending_items_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_pending_items_return_buffer_addr); 117 } 118 } 119 120 // Compile our __lldb_backtrace_recording_get_pending_items() function (from 121 // the source above in g_get_pending_items_function_code) if we don't find that 122 // function in the inferior already with USE_BUILTIN_FUNCTION defined. (e.g. 123 // this would be the case for testing.) 124 // 125 // Insert the __lldb_backtrace_recording_get_pending_items into the inferior 126 // process if needed. 127 // 128 // Write the get_pending_items_arglist into the inferior's memory space to 129 // prepare for the call. 130 // 131 // Returns the address of the arguments written down in the inferior process, 132 // which can be used to make the function call. 133 134 lldb::addr_t AppleGetPendingItemsHandler::SetupGetPendingItemsFunction( 135 Thread &thread, ValueList &get_pending_items_arglist) { 136 ThreadSP thread_sp(thread.shared_from_this()); 137 ExecutionContext exe_ctx(thread_sp); 138 DiagnosticManager diagnostics; 139 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 140 141 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 142 FunctionCaller *get_pending_items_caller = nullptr; 143 144 // Scope for mutex locker: 145 { 146 std::lock_guard<std::mutex> guard(m_get_pending_items_function_mutex); 147 148 // First stage is to make the ClangUtility to hold our injected function: 149 150 if (!m_get_pending_items_impl_code.get()) { 151 if (g_get_pending_items_function_code != NULL) { 152 Status error; 153 m_get_pending_items_impl_code.reset( 154 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 155 g_get_pending_items_function_code, eLanguageTypeObjC, 156 g_get_pending_items_function_name, error)); 157 if (error.Fail()) { 158 if (log) 159 log->Printf("Failed to get UtilityFunction for pending-items " 160 "introspection: %s.", 161 error.AsCString()); 162 return args_addr; 163 } 164 165 if (!m_get_pending_items_impl_code->Install(diagnostics, exe_ctx)) { 166 if (log) { 167 log->Printf("Failed to install pending-items introspection."); 168 diagnostics.Dump(log); 169 } 170 m_get_pending_items_impl_code.reset(); 171 return args_addr; 172 } 173 } else { 174 if (log) 175 log->Printf("No pending-items introspection code found."); 176 return LLDB_INVALID_ADDRESS; 177 } 178 179 // Next make the runner function for our implementation utility function. 180 Status error; 181 ClangASTContext *clang_ast_context = 182 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 183 CompilerType get_pending_items_return_type = 184 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 185 get_pending_items_caller = 186 m_get_pending_items_impl_code->MakeFunctionCaller( 187 get_pending_items_return_type, get_pending_items_arglist, 188 thread_sp, error); 189 if (error.Fail() || get_pending_items_caller == nullptr) { 190 if (log) 191 log->Printf("Failed to install pending-items introspection function " 192 "caller: %s.", 193 error.AsCString()); 194 m_get_pending_items_impl_code.reset(); 195 return args_addr; 196 } 197 } 198 } 199 200 diagnostics.Clear(); 201 202 if (get_pending_items_caller == nullptr) { 203 if (log) 204 log->Printf("Failed to get get_pending_items_caller."); 205 return LLDB_INVALID_ADDRESS; 206 } 207 208 // Now write down the argument values for this particular call. This looks 209 // like it might be a race condition if other threads were calling into here, 210 // but actually it isn't because we allocate a new args structure for this 211 // call by passing args_addr = LLDB_INVALID_ADDRESS... 212 213 if (!get_pending_items_caller->WriteFunctionArguments( 214 exe_ctx, args_addr, get_pending_items_arglist, diagnostics)) { 215 if (log) { 216 log->Printf("Error writing pending-items function arguments."); 217 diagnostics.Dump(log); 218 } 219 220 return args_addr; 221 } 222 223 return args_addr; 224 } 225 226 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 227 AppleGetPendingItemsHandler::GetPendingItems(Thread &thread, addr_t queue, 228 addr_t page_to_free, 229 uint64_t page_to_free_size, 230 Status &error) { 231 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 232 ProcessSP process_sp(thread.CalculateProcess()); 233 TargetSP target_sp(thread.CalculateTarget()); 234 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 235 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 236 237 GetPendingItemsReturnInfo return_value; 238 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 239 return_value.items_buffer_size = 0; 240 return_value.count = 0; 241 242 error.Clear(); 243 244 if (!thread.SafeToCallFunctions()) { 245 if (log) 246 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 247 thread.GetID()); 248 error.SetErrorString("Not safe to call functions on this thread."); 249 return return_value; 250 } 251 252 // Set up the arguments for a call to 253 254 // struct get_pending_items_return_values 255 // { 256 // uint64_t pending_items_buffer_ptr; /* the address of the items 257 // buffer from libBacktraceRecording */ 258 // uint64_t pending_items_buffer_size; /* the size of the items buffer 259 // from libBacktraceRecording */ 260 // uint64_t count; /* the number of items included in the 261 // queues buffer */ 262 // }; 263 // 264 // void __lldb_backtrace_recording_get_pending_items 265 // (struct 266 // get_pending_items_return_values 267 // *return_buffer, 268 // int debug, 269 // uint64_t /* dispatch_queue_t */ 270 // queue 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 CompilerType clang_uint64_type = 289 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 290 Value queue_value; 291 queue_value.SetValueType(Value::eValueTypeScalar); 292 queue_value.SetCompilerType(clang_uint64_type); 293 294 Value page_to_free_value; 295 page_to_free_value.SetValueType(Value::eValueTypeScalar); 296 page_to_free_value.SetCompilerType(clang_void_ptr_type); 297 298 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_pending_items_retbuffer_mutex); 303 if (m_get_pending_items_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_pending_items_return_buffer_addr = bufaddr; 313 } 314 315 ValueList argument_values; 316 317 return_buffer_ptr_value.GetScalar() = m_get_pending_items_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 queue_value.GetScalar() = queue; 324 argument_values.PushValue(queue_value); 325 326 if (page_to_free != LLDB_INVALID_ADDRESS) 327 page_to_free_value.GetScalar() = page_to_free; 328 else 329 page_to_free_value.GetScalar() = 0; 330 argument_values.PushValue(page_to_free_value); 331 332 page_to_free_size_value.GetScalar() = page_to_free_size; 333 argument_values.PushValue(page_to_free_size_value); 334 335 addr_t args_addr = SetupGetPendingItemsFunction(thread, argument_values); 336 337 DiagnosticManager diagnostics; 338 ExecutionContext exe_ctx; 339 FunctionCaller *get_pending_items_caller = 340 m_get_pending_items_impl_code->GetFunctionCaller(); 341 342 EvaluateExpressionOptions options; 343 options.SetUnwindOnError(true); 344 options.SetIgnoreBreakpoints(true); 345 options.SetStopOthers(true); 346 options.SetTimeout(std::chrono::milliseconds(500)); 347 options.SetTryAllThreads(false); 348 options.SetIsForUtilityExpr(true); 349 thread.CalculateExecutionContext(exe_ctx); 350 351 if (get_pending_items_caller == NULL) { 352 error.SetErrorString("Unable to compile function to call " 353 "__introspection_dispatch_queue_get_pending_items"); 354 return return_value; 355 } 356 357 ExpressionResults func_call_ret; 358 Value results; 359 func_call_ret = get_pending_items_caller->ExecuteFunction( 360 exe_ctx, &args_addr, options, diagnostics, results); 361 if (func_call_ret != eExpressionCompleted || !error.Success()) { 362 if (log) 363 log->Printf("Unable to call " 364 "__introspection_dispatch_queue_get_pending_items(), got " 365 "ExpressionResults %d, error contains %s", 366 func_call_ret, error.AsCString("")); 367 error.SetErrorString("Unable to call " 368 "__introspection_dispatch_queue_get_pending_items() " 369 "for list of queues"); 370 return return_value; 371 } 372 373 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 374 m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 375 if (!error.Success() || 376 return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) { 377 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 378 return return_value; 379 } 380 381 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 382 m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 383 384 if (!error.Success()) { 385 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 386 return return_value; 387 } 388 389 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 390 m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 391 if (!error.Success()) { 392 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 393 return return_value; 394 } 395 396 if (log) 397 log->Printf("AppleGetPendingItemsHandler called " 398 "__introspection_dispatch_queue_get_pending_items " 399 "(page_to_free == 0x%" PRIx64 ", size = %" PRId64 400 "), returned page is at 0x%" PRIx64 ", size %" PRId64 401 ", count = %" PRId64, 402 page_to_free, page_to_free_size, return_value.items_buffer_ptr, 403 return_value.items_buffer_size, return_value.count); 404 405 return return_value; 406 } 407