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/FunctionCaller.h" 23 #include "lldb/Expression/UtilityFunction.h" 24 #include "lldb/Symbol/ClangASTContext.h" 25 #include "lldb/Symbol/Symbol.h" 26 #include "lldb/Target/ExecutionContext.h" 27 #include "lldb/Target/Process.h" 28 #include "lldb/Target/Target.h" 29 #include "lldb/Target/Thread.h" 30 31 using namespace lldb; 32 using namespace lldb_private; 33 34 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_name = "__lldb_backtrace_recording_get_pending_items"; 35 const char *AppleGetPendingItemsHandler::g_get_pending_items_function_code = " \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), 104 m_get_pending_items_impl_code (), 105 m_get_pending_items_function_mutex(), 106 m_get_pending_items_return_buffer_addr (LLDB_INVALID_ADDRESS), 107 m_get_pending_items_retbuffer_mutex() 108 { 109 } 110 111 AppleGetPendingItemsHandler::~AppleGetPendingItemsHandler () 112 { 113 } 114 115 void 116 AppleGetPendingItemsHandler::Detach () 117 { 118 119 if (m_process && m_process->IsAlive() && m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) 120 { 121 Mutex::Locker locker; 122 locker.TryLock (m_get_pending_items_retbuffer_mutex); // 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 ExecutionContext exe_ctx (thread.shared_from_this()); 142 StreamString errors; 143 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 144 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 145 FunctionCaller *get_pending_items_caller = nullptr; 146 147 // Scope for mutex locker: 148 { 149 Mutex::Locker locker(m_get_pending_items_function_mutex); 150 151 // First stage is to make the ClangUtility to hold our injected function: 152 153 if (!m_get_pending_items_impl_code.get()) 154 { 155 if (g_get_pending_items_function_code != NULL) 156 { 157 Error error; 158 m_get_pending_items_impl_code.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_pending_items_function_code, 159 eLanguageTypeObjC, 160 g_get_pending_items_function_name, 161 error)); 162 if (error.Fail()) 163 { 164 if (log) 165 log->Printf ("Failed to get UtilityFunction for pending-items introspection: %s.", error.AsCString()); 166 return args_addr; 167 } 168 169 if (!m_get_pending_items_impl_code->Install(errors, exe_ctx)) 170 { 171 if (log) 172 log->Printf ("Failed to install pending-items introspection: %s.", errors.GetData()); 173 m_get_pending_items_impl_code.reset(); 174 return args_addr; 175 } 176 } 177 else 178 { 179 if (log) 180 log->Printf("No pending-items introspection code found."); 181 return LLDB_INVALID_ADDRESS; 182 } 183 184 // Next make the runner function for our implementation utility function. 185 Error error; 186 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 187 CompilerType get_pending_items_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 188 get_pending_items_caller = m_get_pending_items_impl_code->MakeFunctionCaller (get_pending_items_return_type, 189 get_pending_items_arglist, 190 error); 191 if (error.Fail()) 192 { 193 if (log) 194 log->Printf ("Failed to install pending-items introspection function caller: %s.", error.AsCString()); 195 m_get_pending_items_impl_code.reset(); 196 return args_addr; 197 } 198 } 199 200 } 201 202 errors.Clear(); 203 204 if (get_pending_items_caller == nullptr) 205 { 206 if (log) 207 log->Printf ("Failed to get get_pending_items_caller."); 208 return LLDB_INVALID_ADDRESS; 209 } 210 211 // Now write down the argument values for this particular call. This looks like it might be a race condition 212 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 213 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 214 215 if (!get_pending_items_caller->WriteFunctionArguments (exe_ctx, args_addr, get_pending_items_arglist, errors)) 216 { 217 if (log) 218 log->Printf ("Error writing pending-items function arguments: \"%s\".", errors.GetData()); 219 return args_addr; 220 } 221 222 return args_addr; 223 } 224 225 AppleGetPendingItemsHandler::GetPendingItemsReturnInfo 226 AppleGetPendingItemsHandler::GetPendingItems (Thread &thread, addr_t queue, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 227 { 228 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 229 ProcessSP process_sp (thread.CalculateProcess()); 230 TargetSP target_sp (thread.CalculateTarget()); 231 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 232 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 233 234 GetPendingItemsReturnInfo return_value; 235 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 236 return_value.items_buffer_size = 0; 237 return_value.count = 0; 238 239 error.Clear(); 240 241 if (thread.SafeToCallFunctions() == false) 242 { 243 if (log) 244 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 245 error.SetErrorString ("Not safe to call functions on this thread."); 246 return return_value; 247 } 248 249 // Set up the arguments for a call to 250 251 // struct get_pending_items_return_values 252 // { 253 // uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ 254 // uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ 255 // uint64_t count; /* the number of items included in the queues buffer */ 256 // }; 257 // 258 // void __lldb_backtrace_recording_get_pending_items 259 // (struct get_pending_items_return_values *return_buffer, 260 // int debug, 261 // uint64_t /* dispatch_queue_t */ queue 262 // void *page_to_free, 263 // uint64_t page_to_free_size) 264 265 // Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in 266 // the inferior process. 267 268 CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 269 Value return_buffer_ptr_value; 270 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 271 return_buffer_ptr_value.SetCompilerType (clang_void_ptr_type); 272 273 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 274 Value debug_value; 275 debug_value.SetValueType (Value::eValueTypeScalar); 276 debug_value.SetCompilerType (clang_int_type); 277 278 CompilerType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 279 Value queue_value; 280 queue_value.SetValueType (Value::eValueTypeScalar); 281 queue_value.SetCompilerType (clang_uint64_type); 282 283 Value page_to_free_value; 284 page_to_free_value.SetValueType (Value::eValueTypeScalar); 285 page_to_free_value.SetCompilerType (clang_void_ptr_type); 286 287 Value page_to_free_size_value; 288 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 289 page_to_free_size_value.SetCompilerType (clang_uint64_type); 290 291 292 Mutex::Locker locker(m_get_pending_items_retbuffer_mutex); 293 if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) 294 { 295 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 296 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 297 { 298 if (log) 299 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 300 return return_value; 301 } 302 m_get_pending_items_return_buffer_addr = bufaddr; 303 } 304 305 ValueList argument_values; 306 307 return_buffer_ptr_value.GetScalar() = m_get_pending_items_return_buffer_addr; 308 argument_values.PushValue (return_buffer_ptr_value); 309 310 debug_value.GetScalar() = 0; 311 argument_values.PushValue (debug_value); 312 313 queue_value.GetScalar() = queue; 314 argument_values.PushValue (queue_value); 315 316 if (page_to_free != LLDB_INVALID_ADDRESS) 317 page_to_free_value.GetScalar() = page_to_free; 318 else 319 page_to_free_value.GetScalar() = 0; 320 argument_values.PushValue (page_to_free_value); 321 322 page_to_free_size_value.GetScalar() = page_to_free_size; 323 argument_values.PushValue (page_to_free_size_value); 324 325 addr_t args_addr = SetupGetPendingItemsFunction (thread, argument_values); 326 327 StreamString errors; 328 ExecutionContext exe_ctx; 329 FunctionCaller *get_pending_items_caller = m_get_pending_items_impl_code->GetFunctionCaller(); 330 331 EvaluateExpressionOptions options; 332 options.SetUnwindOnError (true); 333 options.SetIgnoreBreakpoints (true); 334 options.SetStopOthers (true); 335 options.SetTimeoutUsec(500000); 336 options.SetTryAllThreads (false); 337 thread.CalculateExecutionContext (exe_ctx); 338 339 if (get_pending_items_caller == NULL) 340 { 341 error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_get_pending_items"); 342 return return_value; 343 } 344 345 346 ExpressionResults func_call_ret; 347 Value results; 348 func_call_ret = get_pending_items_caller->ExecuteFunction (exe_ctx, &args_addr, options, errors, results); 349 if (func_call_ret != eExpressionCompleted || !error.Success()) 350 { 351 if (log) 352 log->Printf ("Unable to call __introspection_dispatch_queue_get_pending_items(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 353 error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_pending_items() for list of queues"); 354 return return_value; 355 } 356 357 return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 358 if (!error.Success() || return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) 359 { 360 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 361 return return_value; 362 } 363 364 return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 8, 8, 0, error); 365 366 if (!error.Success()) 367 { 368 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 369 return return_value; 370 } 371 372 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 16, 8, 0, error); 373 if (!error.Success()) 374 { 375 return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; 376 return return_value; 377 } 378 379 if (log) 380 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); 381 382 return return_value; 383 } 384