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/ConstString.h" 19 #include "lldb/Core/Log.h" 20 #include "lldb/Core/Module.h" 21 #include "lldb/Core/StreamString.h" 22 #include "lldb/Core/Value.h" 23 #include "lldb/Expression/DiagnosticManager.h" 24 #include "lldb/Expression/FunctionCaller.h" 25 #include "lldb/Expression/UtilityFunction.h" 26 #include "lldb/Symbol/ClangASTContext.h" 27 #include "lldb/Symbol/Symbol.h" 28 #include "lldb/Target/ExecutionContext.h" 29 #include "lldb/Target/Process.h" 30 #include "lldb/Target/Target.h" 31 #include "lldb/Target/Thread.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 the 125 // source above in g_get_pending_items_function_code) if we don't find that 126 // function in the inferior 127 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for 128 // testing.) 129 // 130 // Insert the __lldb_backtrace_recording_get_pending_items into the inferior 131 // process if needed. 132 // 133 // Write the get_pending_items_arglist into the inferior's memory space to 134 // prepare for the call. 135 // 136 // Returns the address of the arguments written down in the inferior process, 137 // which can be used to 138 // make the function call. 139 140 lldb::addr_t AppleGetPendingItemsHandler::SetupGetPendingItemsFunction( 141 Thread &thread, ValueList &get_pending_items_arglist) { 142 ThreadSP thread_sp(thread.shared_from_this()); 143 ExecutionContext exe_ctx(thread_sp); 144 DiagnosticManager diagnostics; 145 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 146 147 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 148 FunctionCaller *get_pending_items_caller = nullptr; 149 150 // Scope for mutex locker: 151 { 152 std::lock_guard<std::mutex> guard(m_get_pending_items_function_mutex); 153 154 // First stage is to make the ClangUtility to hold our injected function: 155 156 if (!m_get_pending_items_impl_code.get()) { 157 if (g_get_pending_items_function_code != NULL) { 158 Error error; 159 m_get_pending_items_impl_code.reset( 160 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 161 g_get_pending_items_function_code, eLanguageTypeObjC, 162 g_get_pending_items_function_name, error)); 163 if (error.Fail()) { 164 if (log) 165 log->Printf("Failed to get UtilityFunction for pending-items " 166 "introspection: %s.", 167 error.AsCString()); 168 return args_addr; 169 } 170 171 if (!m_get_pending_items_impl_code->Install(diagnostics, exe_ctx)) { 172 if (log) { 173 log->Printf("Failed to install pending-items introspection."); 174 diagnostics.Dump(log); 175 } 176 m_get_pending_items_impl_code.reset(); 177 return args_addr; 178 } 179 } else { 180 if (log) 181 log->Printf("No pending-items introspection code found."); 182 return LLDB_INVALID_ADDRESS; 183 } 184 185 // Next make the runner function for our implementation utility function. 186 Error error; 187 ClangASTContext *clang_ast_context = 188 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 189 CompilerType get_pending_items_return_type = 190 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 191 get_pending_items_caller = 192 m_get_pending_items_impl_code->MakeFunctionCaller( 193 get_pending_items_return_type, get_pending_items_arglist, 194 thread_sp, error); 195 if (error.Fail()) { 196 if (log) 197 log->Printf("Failed to install pending-items introspection function " 198 "caller: %s.", 199 error.AsCString()); 200 m_get_pending_items_impl_code.reset(); 201 return args_addr; 202 } 203 } 204 } 205 206 diagnostics.Clear(); 207 208 if (get_pending_items_caller == nullptr) { 209 if (log) 210 log->Printf("Failed to get get_pending_items_caller."); 211 return LLDB_INVALID_ADDRESS; 212 } 213 214 // Now write down the argument values for this particular call. This looks 215 // like it might be a race condition 216 // if other threads were calling into here, but actually it isn't because we 217 // allocate a new args structure for 218 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 219 220 if (!get_pending_items_caller->WriteFunctionArguments( 221 exe_ctx, args_addr, get_pending_items_arglist, diagnostics)) { 222 if (log) { 223 log->Printf("Error writing pending-items function arguments."); 224 diagnostics.Dump(log); 225 } 226 227 return args_addr; 228 } 229 230 return args_addr; 231 } 232 233 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 234 AppleGetPendingItemsHandler::GetPendingItems(Thread &thread, addr_t queue, 235 addr_t page_to_free, 236 uint64_t page_to_free_size, 237 Error &error) { 238 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 239 ProcessSP process_sp(thread.CalculateProcess()); 240 TargetSP target_sp(thread.CalculateTarget()); 241 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 242 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 243 244 GetPendingItemsReturnInfo return_value; 245 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 246 return_value.items_buffer_size = 0; 247 return_value.count = 0; 248 249 error.Clear(); 250 251 if (thread.SafeToCallFunctions() == false) { 252 if (log) 253 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 254 thread.GetID()); 255 error.SetErrorString("Not safe to call functions on this thread."); 256 return return_value; 257 } 258 259 // Set up the arguments for a call to 260 261 // struct get_pending_items_return_values 262 // { 263 // uint64_t pending_items_buffer_ptr; /* the address of the items 264 // buffer from libBacktraceRecording */ 265 // uint64_t pending_items_buffer_size; /* the size of the items buffer 266 // from libBacktraceRecording */ 267 // uint64_t count; /* the number of items included in the 268 // queues buffer */ 269 // }; 270 // 271 // void __lldb_backtrace_recording_get_pending_items 272 // (struct 273 // get_pending_items_return_values 274 // *return_buffer, 275 // int debug, 276 // uint64_t /* dispatch_queue_t */ 277 // queue 278 // void *page_to_free, 279 // uint64_t page_to_free_size) 280 281 // Where the return_buffer argument points to a 24 byte region of memory 282 // already allocated by lldb in 283 // the inferior process. 284 285 CompilerType clang_void_ptr_type = 286 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 287 Value return_buffer_ptr_value; 288 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 289 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 290 291 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 292 Value debug_value; 293 debug_value.SetValueType(Value::eValueTypeScalar); 294 debug_value.SetCompilerType(clang_int_type); 295 296 CompilerType clang_uint64_type = 297 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 298 Value queue_value; 299 queue_value.SetValueType(Value::eValueTypeScalar); 300 queue_value.SetCompilerType(clang_uint64_type); 301 302 Value page_to_free_value; 303 page_to_free_value.SetValueType(Value::eValueTypeScalar); 304 page_to_free_value.SetCompilerType(clang_void_ptr_type); 305 306 Value page_to_free_size_value; 307 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 308 page_to_free_size_value.SetCompilerType(clang_uint64_type); 309 310 std::lock_guard<std::mutex> guard(m_get_pending_items_retbuffer_mutex); 311 if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) { 312 addr_t bufaddr = process_sp->AllocateMemory( 313 32, ePermissionsReadable | ePermissionsWritable, error); 314 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 315 if (log) 316 log->Printf("Failed to allocate memory for return buffer for get " 317 "current queues func call"); 318 return return_value; 319 } 320 m_get_pending_items_return_buffer_addr = bufaddr; 321 } 322 323 ValueList argument_values; 324 325 return_buffer_ptr_value.GetScalar() = m_get_pending_items_return_buffer_addr; 326 argument_values.PushValue(return_buffer_ptr_value); 327 328 debug_value.GetScalar() = 0; 329 argument_values.PushValue(debug_value); 330 331 queue_value.GetScalar() = queue; 332 argument_values.PushValue(queue_value); 333 334 if (page_to_free != LLDB_INVALID_ADDRESS) 335 page_to_free_value.GetScalar() = page_to_free; 336 else 337 page_to_free_value.GetScalar() = 0; 338 argument_values.PushValue(page_to_free_value); 339 340 page_to_free_size_value.GetScalar() = page_to_free_size; 341 argument_values.PushValue(page_to_free_size_value); 342 343 addr_t args_addr = SetupGetPendingItemsFunction(thread, argument_values); 344 345 DiagnosticManager diagnostics; 346 ExecutionContext exe_ctx; 347 FunctionCaller *get_pending_items_caller = 348 m_get_pending_items_impl_code->GetFunctionCaller(); 349 350 EvaluateExpressionOptions options; 351 options.SetUnwindOnError(true); 352 options.SetIgnoreBreakpoints(true); 353 options.SetStopOthers(true); 354 options.SetTimeoutUsec(500000); 355 options.SetTryAllThreads(false); 356 thread.CalculateExecutionContext(exe_ctx); 357 358 if (get_pending_items_caller == NULL) { 359 error.SetErrorString("Unable to compile function to call " 360 "__introspection_dispatch_queue_get_pending_items"); 361 return return_value; 362 } 363 364 ExpressionResults func_call_ret; 365 Value results; 366 func_call_ret = get_pending_items_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 " 371 "__introspection_dispatch_queue_get_pending_items(), got " 372 "ExpressionResults %d, error contains %s", 373 func_call_ret, error.AsCString("")); 374 error.SetErrorString("Unable to call " 375 "__introspection_dispatch_queue_get_pending_items() " 376 "for list of queues"); 377 return return_value; 378 } 379 380 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 381 m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 382 if (!error.Success() || 383 return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) { 384 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 385 return return_value; 386 } 387 388 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 389 m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 390 391 if (!error.Success()) { 392 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 393 return return_value; 394 } 395 396 return_value.count = m_process->ReadUnsignedIntegerFromMemory( 397 m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 398 if (!error.Success()) { 399 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 400 return return_value; 401 } 402 403 if (log) 404 log->Printf("AppleGetPendingItemsHandler called " 405 "__introspection_dispatch_queue_get_pending_items " 406 "(page_to_free == 0x%" PRIx64 ", size = %" PRId64 407 "), returned page is at 0x%" PRIx64 ", size %" PRId64 408 ", count = %" PRId64, 409 page_to_free, page_to_free_size, return_value.items_buffer_ptr, 410 return_value.items_buffer_size, return_value.count); 411 412 return return_value; 413 } 414