1 //===-- AppleGetPendingItemsHandler.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 "AppleGetPendingItemsHandler.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 17 #include "lldb/Core/ConstString.h" 18 #include "lldb/Core/Log.h" 19 #include "lldb/Core/Module.h" 20 #include "lldb/Core/StreamString.h" 21 #include "lldb/Core/Value.h" 22 #include "lldb/Expression/DiagnosticManager.h" 23 #include "lldb/Expression/FunctionCaller.h" 24 #include "lldb/Expression/UtilityFunction.h" 25 #include "lldb/Symbol/ClangASTContext.h" 26 #include "lldb/Symbol/Symbol.h" 27 #include "lldb/Target/ExecutionContext.h" 28 #include "lldb/Target/Process.h" 29 #include "lldb/Target/Target.h" 30 #include "lldb/Target/Thread.h" 31 32 using namespace lldb; 33 using namespace lldb_private; 34 35 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_name = "__lldb_backtrace_recording_get_pending_items"; 36 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_code = " \n\ 37 extern \"C\" \n\ 38 { \n\ 39 /* \n\ 40 * mach defines \n\ 41 */ \n\ 42 \n\ 43 typedef unsigned int uint32_t; \n\ 44 typedef unsigned long long uint64_t; \n\ 45 typedef uint32_t mach_port_t; \n\ 46 typedef mach_port_t vm_map_t; \n\ 47 typedef int kern_return_t; \n\ 48 typedef uint64_t mach_vm_address_t; \n\ 49 typedef uint64_t mach_vm_size_t; \n\ 50 \n\ 51 mach_port_t mach_task_self (); \n\ 52 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 53 \n\ 54 /* \n\ 55 * libBacktraceRecording defines \n\ 56 */ \n\ 57 \n\ 58 typedef uint32_t queue_list_scope_t; \n\ 59 typedef void *dispatch_queue_t; \n\ 60 typedef void *introspection_dispatch_queue_info_t; \n\ 61 typedef void *introspection_dispatch_item_info_ref; \n\ 62 \n\ 63 extern uint64_t __introspection_dispatch_queue_get_pending_items (dispatch_queue_t queue, \n\ 64 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 65 uint64_t *returned_queues_buffer_size); \n\ 66 extern int printf(const char *format, ...); \n\ 67 \n\ 68 /* \n\ 69 * return type define \n\ 70 */ \n\ 71 \n\ 72 struct get_pending_items_return_values \n\ 73 { \n\ 74 uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 75 uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 76 uint64_t count; /* the number of items included in the queues buffer */ \n\ 77 }; \n\ 78 \n\ 79 void __lldb_backtrace_recording_get_pending_items \n\ 80 (struct get_pending_items_return_values *return_buffer, \n\ 81 int debug, \n\ 82 uint64_t /* dispatch_queue_t */ queue, \n\ 83 void *page_to_free, \n\ 84 uint64_t page_to_free_size) \n\ 85 { \n\ 86 if (debug) \n\ 87 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\ 88 if (page_to_free != 0) \n\ 89 { \n\ 90 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 91 } \n\ 92 \n\ 93 return_buffer->count = __introspection_dispatch_queue_get_pending_items ( \n\ 94 (void*) queue, \n\ 95 (void**)&return_buffer->pending_items_buffer_ptr, \n\ 96 &return_buffer->pending_items_buffer_size); \n\ 97 if (debug) \n\ 98 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 99 } \n\ 100 } \n\ 101 "; 102 103 AppleGetPendingItemsHandler::AppleGetPendingItemsHandler(Process *process) 104 : m_process(process), 105 m_get_pending_items_impl_code(), 106 m_get_pending_items_function_mutex(), 107 m_get_pending_items_return_buffer_addr(LLDB_INVALID_ADDRESS), 108 m_get_pending_items_retbuffer_mutex() 109 { 110 } 111 112 AppleGetPendingItemsHandler::~AppleGetPendingItemsHandler () 113 { 114 } 115 116 void 117 AppleGetPendingItemsHandler::Detach() 118 { 119 if (m_process && m_process->IsAlive() && m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) 120 { 121 std::unique_lock<std::mutex> lock(m_get_pending_items_retbuffer_mutex, std::defer_lock); 122 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 123 m_process->DeallocateMemory(m_get_pending_items_return_buffer_addr); 124 } 125 } 126 127 // Compile our __lldb_backtrace_recording_get_pending_items() function (from the 128 // source above in g_get_pending_items_function_code) if we don't find that function in the inferior 129 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 130 // 131 // Insert the __lldb_backtrace_recording_get_pending_items into the inferior process if needed. 132 // 133 // Write the get_pending_items_arglist into the inferior's memory space to prepare for the call. 134 // 135 // Returns the address of the arguments written down in the inferior process, which can be used to 136 // make the function call. 137 138 lldb::addr_t 139 AppleGetPendingItemsHandler::SetupGetPendingItemsFunction(Thread &thread, ValueList &get_pending_items_arglist) 140 { 141 ThreadSP thread_sp (thread.shared_from_this()); 142 ExecutionContext exe_ctx (thread_sp); 143 DiagnosticManager diagnostics; 144 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 145 146 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 147 FunctionCaller *get_pending_items_caller = nullptr; 148 149 // Scope for mutex locker: 150 { 151 std::lock_guard<std::mutex> guard(m_get_pending_items_function_mutex); 152 153 // First stage is to make the ClangUtility to hold our injected function: 154 155 if (!m_get_pending_items_impl_code.get()) 156 { 157 if (g_get_pending_items_function_code != NULL) 158 { 159 Error error; 160 m_get_pending_items_impl_code.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_pending_items_function_code, 161 eLanguageTypeObjC, 162 g_get_pending_items_function_name, 163 error)); 164 if (error.Fail()) 165 { 166 if (log) 167 log->Printf ("Failed to get UtilityFunction for pending-items introspection: %s.", error.AsCString()); 168 return args_addr; 169 } 170 171 if (!m_get_pending_items_impl_code->Install(diagnostics, exe_ctx)) 172 { 173 if (log) 174 { 175 log->Printf("Failed to install pending-items introspection."); 176 diagnostics.Dump(log); 177 } 178 m_get_pending_items_impl_code.reset(); 179 return args_addr; 180 } 181 } 182 else 183 { 184 if (log) 185 log->Printf("No pending-items introspection code found."); 186 return LLDB_INVALID_ADDRESS; 187 } 188 189 // Next make the runner function for our implementation utility function. 190 Error error; 191 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 192 CompilerType get_pending_items_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 193 get_pending_items_caller = m_get_pending_items_impl_code->MakeFunctionCaller (get_pending_items_return_type, 194 get_pending_items_arglist, 195 thread_sp, 196 error); 197 if (error.Fail()) 198 { 199 if (log) 200 log->Printf ("Failed to install pending-items introspection function caller: %s.", error.AsCString()); 201 m_get_pending_items_impl_code.reset(); 202 return args_addr; 203 } 204 } 205 } 206 207 diagnostics.Clear(); 208 209 if (get_pending_items_caller == nullptr) 210 { 211 if (log) 212 log->Printf ("Failed to get get_pending_items_caller."); 213 return LLDB_INVALID_ADDRESS; 214 } 215 216 // Now write down the argument values for this particular call. This looks like it might be a race condition 217 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 218 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 219 220 if (!get_pending_items_caller->WriteFunctionArguments(exe_ctx, args_addr, get_pending_items_arglist, diagnostics)) 221 { 222 if (log) 223 { 224 log->Printf("Error writing pending-items function arguments."); 225 diagnostics.Dump(log); 226 } 227 228 return args_addr; 229 } 230 231 return args_addr; 232 } 233 234 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 235 AppleGetPendingItemsHandler::GetPendingItems (Thread &thread, addr_t queue, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 236 { 237 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 238 ProcessSP process_sp (thread.CalculateProcess()); 239 TargetSP target_sp (thread.CalculateTarget()); 240 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 241 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 242 243 GetPendingItemsReturnInfo return_value; 244 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 245 return_value.items_buffer_size = 0; 246 return_value.count = 0; 247 248 error.Clear(); 249 250 if (thread.SafeToCallFunctions() == false) 251 { 252 if (log) 253 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 254 error.SetErrorString ("Not safe to call functions on this thread."); 255 return return_value; 256 } 257 258 // Set up the arguments for a call to 259 260 // struct get_pending_items_return_values 261 // { 262 // uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ 263 // uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ 264 // uint64_t count; /* the number of items included in the queues buffer */ 265 // }; 266 // 267 // void __lldb_backtrace_recording_get_pending_items 268 // (struct get_pending_items_return_values *return_buffer, 269 // int debug, 270 // uint64_t /* dispatch_queue_t */ 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 already allocated by lldb in 275 // the inferior process. 276 277 CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 278 Value return_buffer_ptr_value; 279 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 280 return_buffer_ptr_value.SetCompilerType (clang_void_ptr_type); 281 282 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 283 Value debug_value; 284 debug_value.SetValueType (Value::eValueTypeScalar); 285 debug_value.SetCompilerType (clang_int_type); 286 287 CompilerType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 288 Value queue_value; 289 queue_value.SetValueType (Value::eValueTypeScalar); 290 queue_value.SetCompilerType (clang_uint64_type); 291 292 Value page_to_free_value; 293 page_to_free_value.SetValueType (Value::eValueTypeScalar); 294 page_to_free_value.SetCompilerType (clang_void_ptr_type); 295 296 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 std::lock_guard<std::mutex> guard(m_get_pending_items_retbuffer_mutex); 301 if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) 302 { 303 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 304 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 305 { 306 if (log) 307 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 308 return return_value; 309 } 310 m_get_pending_items_return_buffer_addr = bufaddr; 311 } 312 313 ValueList argument_values; 314 315 return_buffer_ptr_value.GetScalar() = m_get_pending_items_return_buffer_addr; 316 argument_values.PushValue (return_buffer_ptr_value); 317 318 debug_value.GetScalar() = 0; 319 argument_values.PushValue (debug_value); 320 321 queue_value.GetScalar() = queue; 322 argument_values.PushValue (queue_value); 323 324 if (page_to_free != LLDB_INVALID_ADDRESS) 325 page_to_free_value.GetScalar() = page_to_free; 326 else 327 page_to_free_value.GetScalar() = 0; 328 argument_values.PushValue (page_to_free_value); 329 330 page_to_free_size_value.GetScalar() = page_to_free_size; 331 argument_values.PushValue (page_to_free_size_value); 332 333 addr_t args_addr = SetupGetPendingItemsFunction(thread, argument_values); 334 335 DiagnosticManager diagnostics; 336 ExecutionContext exe_ctx; 337 FunctionCaller *get_pending_items_caller = m_get_pending_items_impl_code->GetFunctionCaller(); 338 339 EvaluateExpressionOptions options; 340 options.SetUnwindOnError (true); 341 options.SetIgnoreBreakpoints (true); 342 options.SetStopOthers (true); 343 options.SetTimeoutUsec(500000); 344 options.SetTryAllThreads (false); 345 thread.CalculateExecutionContext (exe_ctx); 346 347 if (get_pending_items_caller == NULL) 348 { 349 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_get_pending_items"); 350 return return_value; 351 } 352 353 ExpressionResults func_call_ret; 354 Value results; 355 func_call_ret = get_pending_items_caller->ExecuteFunction(exe_ctx, &args_addr, options, diagnostics, results); 356 if (func_call_ret != eExpressionCompleted || !error.Success()) 357 { 358 if (log) 359 log->Printf ("Unable to call __introspection_dispatch_queue_get_pending_items(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 360 error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_pending_items() for list of queues"); 361 return return_value; 362 } 363 364 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 365 if (!error.Success() || return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) 366 { 367 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 368 return return_value; 369 } 370 371 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 372 373 if (!error.Success()) 374 { 375 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 376 return return_value; 377 } 378 379 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 380 if (!error.Success()) 381 { 382 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 383 return return_value; 384 } 385 386 if (log) 387 log->Printf ("AppleGetPendingItemsHandler called __introspection_dispatch_queue_get_pending_items (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.items_buffer_ptr, return_value.items_buffer_size, return_value.count); 388 389 return return_value; 390 } 391