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 { 119 120 if (m_process && m_process->IsAlive() && m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) 121 { 122 Mutex::Locker locker; 123 locker.TryLock (m_get_pending_items_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 124 m_process->DeallocateMemory (m_get_pending_items_return_buffer_addr); 125 } 126 } 127 128 // Compile our __lldb_backtrace_recording_get_pending_items() function (from the 129 // source above in g_get_pending_items_function_code) if we don't find that function in the inferior 130 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 131 // 132 // Insert the __lldb_backtrace_recording_get_pending_items into the inferior process if needed. 133 // 134 // Write the get_pending_items_arglist into the inferior's memory space to prepare for the call. 135 // 136 // Returns the address of the arguments written down in the inferior process, which can be used to 137 // make the function call. 138 139 lldb::addr_t 140 AppleGetPendingItemsHandler::SetupGetPendingItemsFunction(Thread &thread, ValueList &get_pending_items_arglist) 141 { 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 Mutex::Locker locker(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 { 158 if (g_get_pending_items_function_code != NULL) 159 { 160 Error error; 161 m_get_pending_items_impl_code.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_pending_items_function_code, 162 eLanguageTypeObjC, 163 g_get_pending_items_function_name, 164 error)); 165 if (error.Fail()) 166 { 167 if (log) 168 log->Printf ("Failed to get UtilityFunction for pending-items introspection: %s.", error.AsCString()); 169 return args_addr; 170 } 171 172 if (!m_get_pending_items_impl_code->Install(diagnostics, exe_ctx)) 173 { 174 if (log) 175 { 176 log->Printf("Failed to install pending-items introspection."); 177 diagnostics.Dump(log); 178 } 179 m_get_pending_items_impl_code.reset(); 180 return args_addr; 181 } 182 } 183 else 184 { 185 if (log) 186 log->Printf("No pending-items introspection code found."); 187 return LLDB_INVALID_ADDRESS; 188 } 189 190 // Next make the runner function for our implementation utility function. 191 Error error; 192 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 193 CompilerType get_pending_items_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 194 get_pending_items_caller = m_get_pending_items_impl_code->MakeFunctionCaller (get_pending_items_return_type, 195 get_pending_items_arglist, 196 thread_sp, 197 error); 198 if (error.Fail()) 199 { 200 if (log) 201 log->Printf ("Failed to install pending-items introspection function caller: %s.", error.AsCString()); 202 m_get_pending_items_impl_code.reset(); 203 return args_addr; 204 } 205 } 206 } 207 208 diagnostics.Clear(); 209 210 if (get_pending_items_caller == nullptr) 211 { 212 if (log) 213 log->Printf ("Failed to get get_pending_items_caller."); 214 return LLDB_INVALID_ADDRESS; 215 } 216 217 // Now write down the argument values for this particular call. This looks like it might be a race condition 218 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 219 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 220 221 if (!get_pending_items_caller->WriteFunctionArguments(exe_ctx, args_addr, get_pending_items_arglist, diagnostics)) 222 { 223 if (log) 224 { 225 log->Printf("Error writing pending-items function arguments."); 226 diagnostics.Dump(log); 227 } 228 229 return args_addr; 230 } 231 232 return args_addr; 233 } 234 235 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 236 AppleGetPendingItemsHandler::GetPendingItems (Thread &thread, addr_t queue, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 237 { 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 { 253 if (log) 254 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, 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 buffer from libBacktraceRecording */ 264 // uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ 265 // uint64_t count; /* the number of items included in the queues buffer */ 266 // }; 267 // 268 // void __lldb_backtrace_recording_get_pending_items 269 // (struct get_pending_items_return_values *return_buffer, 270 // int debug, 271 // uint64_t /* dispatch_queue_t */ queue 272 // void *page_to_free, 273 // uint64_t page_to_free_size) 274 275 // Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in 276 // the inferior process. 277 278 CompilerType clang_void_ptr_type = 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 = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 289 Value queue_value; 290 queue_value.SetValueType (Value::eValueTypeScalar); 291 queue_value.SetCompilerType (clang_uint64_type); 292 293 Value page_to_free_value; 294 page_to_free_value.SetValueType (Value::eValueTypeScalar); 295 page_to_free_value.SetCompilerType (clang_void_ptr_type); 296 297 Value page_to_free_size_value; 298 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 299 page_to_free_size_value.SetCompilerType (clang_uint64_type); 300 301 302 Mutex::Locker locker(m_get_pending_items_retbuffer_mutex); 303 if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) 304 { 305 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 306 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 307 { 308 if (log) 309 log->Printf ("Failed to allocate memory for return buffer for get 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 = m_get_pending_items_impl_code->GetFunctionCaller(); 340 341 EvaluateExpressionOptions options; 342 options.SetUnwindOnError (true); 343 options.SetIgnoreBreakpoints (true); 344 options.SetStopOthers (true); 345 options.SetTimeoutUsec(500000); 346 options.SetTryAllThreads (false); 347 thread.CalculateExecutionContext (exe_ctx); 348 349 if (get_pending_items_caller == NULL) 350 { 351 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_get_pending_items"); 352 return return_value; 353 } 354 355 ExpressionResults func_call_ret; 356 Value results; 357 func_call_ret = get_pending_items_caller->ExecuteFunction(exe_ctx, &args_addr, options, diagnostics, results); 358 if (func_call_ret != eExpressionCompleted || !error.Success()) 359 { 360 if (log) 361 log->Printf ("Unable to call __introspection_dispatch_queue_get_pending_items(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 362 error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_pending_items() for list of queues"); 363 return return_value; 364 } 365 366 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 367 if (!error.Success() || return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) 368 { 369 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 370 return return_value; 371 } 372 373 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 374 375 if (!error.Success()) 376 { 377 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 378 return return_value; 379 } 380 381 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 382 if (!error.Success()) 383 { 384 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 385 return return_value; 386 } 387 388 if (log) 389 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); 390 391 return return_value; 392 } 393