1 //===-- AppleGetQueuesHandler.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 "AppleGetQueuesHandler.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 #include "lldb/Core/ConstString.h" 17 #include "lldb/Core/Log.h" 18 #include "lldb/Core/Module.h" 19 #include "lldb/Core/StreamString.h" 20 #include "lldb/Core/Value.h" 21 #include "lldb/Expression/FunctionCaller.h" 22 #include "lldb/Expression/UtilityFunction.h" 23 #include "lldb/Symbol/ClangASTContext.h" 24 #include "lldb/Symbol/Symbol.h" 25 #include "lldb/Target/ExecutionContext.h" 26 #include "lldb/Target/Process.h" 27 #include "lldb/Target/Target.h" 28 #include "lldb/Target/Thread.h" 29 30 using namespace lldb; 31 using namespace lldb_private; 32 33 const char *AppleGetQueuesHandler::g_get_current_queues_function_name = "__lldb_backtrace_recording_get_current_queues"; 34 const char *AppleGetQueuesHandler::g_get_current_queues_function_code = " \n\ 35 extern \"C\" \n\ 36 { \n\ 37 /* \n\ 38 * mach defines \n\ 39 */ \n\ 40 \n\ 41 typedef unsigned int uint32_t; \n\ 42 typedef unsigned long long uint64_t; \n\ 43 typedef uint32_t mach_port_t; \n\ 44 typedef mach_port_t vm_map_t; \n\ 45 typedef int kern_return_t; \n\ 46 typedef uint64_t mach_vm_address_t; \n\ 47 typedef uint64_t mach_vm_size_t; \n\ 48 \n\ 49 mach_port_t mach_task_self (); \n\ 50 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 51 \n\ 52 /* \n\ 53 * libBacktraceRecording defines \n\ 54 */ \n\ 55 \n\ 56 typedef uint32_t queue_list_scope_t; \n\ 57 typedef void *introspection_dispatch_queue_info_t; \n\ 58 \n\ 59 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ 60 introspection_dispatch_queue_info_t *returned_queues_buffer, \n\ 61 uint64_t *returned_queues_buffer_size); \n\ 62 extern int printf(const char *format, ...); \n\ 63 \n\ 64 /* \n\ 65 * return type define \n\ 66 */ \n\ 67 \n\ 68 struct get_current_queues_return_values \n\ 69 { \n\ 70 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ 71 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ 72 uint64_t count; /* the number of queues included in the queues buffer */ \n\ 73 }; \n\ 74 \n\ 75 void __lldb_backtrace_recording_get_current_queues \n\ 76 (struct get_current_queues_return_values *return_buffer, \n\ 77 int debug, \n\ 78 void *page_to_free, \n\ 79 uint64_t page_to_free_size) \n\ 80 { \n\ 81 if (debug) \n\ 82 printf (\"entering get_current_queues with args %p, %d, 0x%p, 0x%llx\\n\", return_buffer, debug, page_to_free, page_to_free_size); \n\ 83 if (page_to_free != 0) \n\ 84 { \n\ 85 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 86 } \n\ 87 \n\ 88 return_buffer->count = __introspection_dispatch_get_queues ( \n\ 89 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ 90 (void**)&return_buffer->queues_buffer_ptr, \n\ 91 &return_buffer->queues_buffer_size); \n\ 92 if (debug) \n\ 93 printf(\"result was count %lld\\n\", return_buffer->count); \n\ 94 } \n\ 95 } \n\ 96 "; 97 98 AppleGetQueuesHandler::AppleGetQueuesHandler (Process *process) : 99 m_process (process), 100 m_get_queues_impl_code_up (), 101 m_get_queues_function_mutex(), 102 m_get_queues_return_buffer_addr (LLDB_INVALID_ADDRESS), 103 m_get_queues_retbuffer_mutex() 104 { 105 } 106 107 AppleGetQueuesHandler::~AppleGetQueuesHandler () 108 { 109 } 110 111 void 112 AppleGetQueuesHandler::Detach () 113 { 114 115 if (m_process && m_process->IsAlive() && m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) 116 { 117 Mutex::Locker locker; 118 locker.TryLock (m_get_queues_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer 119 m_process->DeallocateMemory (m_get_queues_return_buffer_addr); 120 } 121 } 122 123 // Construct a CompilerType for the structure that g_get_current_queues_function_code will return by value 124 // so we can extract the fields after performing the function call. 125 // i.e. we are getting this struct returned to us: 126 // 127 // struct get_current_queues_return_values 128 // { 129 // introspection_dispatch_queue_info_t *queues_buffer; 130 // uint64_t queues_buffer_size; 131 // uint64_t count; 132 // }; 133 134 135 // Compile our __lldb_backtrace_recording_get_current_queues() function (from the 136 // source above in g_get_current_queues_function_code) if we don't find that function in the inferior 137 // already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.) 138 // 139 // Insert the __lldb_backtrace_recording_get_current_queues into the inferior process if needed. 140 // 141 // Write the get_queues_arglist into the inferior's memory space to prepare for the call. 142 // 143 // Returns the address of the arguments written down in the inferior process, which can be used to 144 // make the function call. 145 146 lldb::addr_t 147 AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_queues_arglist) 148 { 149 ExecutionContext exe_ctx (thread.shared_from_this()); 150 Address impl_code_address; 151 StreamString errors; 152 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 153 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 154 155 FunctionCaller *get_queues_caller = nullptr; 156 157 // Scope for mutex locker: 158 { 159 Mutex::Locker locker(m_get_queues_function_mutex); 160 161 // First stage is to make the ClangUtility to hold our injected function: 162 163 if (!m_get_queues_impl_code_up.get()) 164 { 165 if (g_get_current_queues_function_code != NULL) 166 { 167 Error error; 168 m_get_queues_impl_code_up.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_current_queues_function_code, 169 eLanguageTypeC, 170 g_get_current_queues_function_name, 171 error)); 172 if (error.Fail()) 173 { 174 if (log) 175 log->Printf ("Failed to get UtilityFunction for queues introspection: %s.", error.AsCString()); 176 return args_addr; 177 } 178 179 if (!m_get_queues_impl_code_up->Install(errors, exe_ctx)) 180 { 181 if (log) 182 log->Printf ("Failed to install queues introspection: %s.", errors.GetData()); 183 m_get_queues_impl_code_up.reset(); 184 return args_addr; 185 } 186 } 187 else 188 { 189 if (log) 190 log->Printf("No queues introspection code found."); 191 errors.Printf ("No queues introspection code found."); 192 return LLDB_INVALID_ADDRESS; 193 } 194 } 195 196 // Next make the runner function for our implementation utility function. 197 ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 198 CompilerType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 199 Error error; 200 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller (get_queues_return_type, 201 get_queues_arglist, 202 error); 203 if (error.Fail()) 204 { 205 if (log) 206 log->Printf ("Could not get function caller for get-queues function: %s.", error.AsCString()); 207 return args_addr; 208 } 209 } 210 211 errors.Clear(); 212 213 // Now write down the argument values for this particular call. This looks like it might be a race condition 214 // if other threads were calling into here, but actually it isn't because we allocate a new args structure for 215 // this call by passing args_addr = LLDB_INVALID_ADDRESS... 216 217 if (!get_queues_caller->WriteFunctionArguments (exe_ctx, args_addr, get_queues_arglist, errors)) 218 { 219 if (log) 220 log->Printf ("Error writing get-queues function arguments: \"%s\".", errors.GetData()); 221 return args_addr; 222 } 223 224 return args_addr; 225 } 226 227 AppleGetQueuesHandler::GetQueuesReturnInfo 228 AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, uint64_t page_to_free_size, Error &error) 229 { 230 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 231 ProcessSP process_sp (thread.CalculateProcess()); 232 TargetSP target_sp (thread.CalculateTarget()); 233 ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 234 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); 235 236 GetQueuesReturnInfo return_value; 237 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 238 return_value.queues_buffer_size = 0; 239 return_value.count = 0; 240 241 error.Clear(); 242 243 if (thread.SafeToCallFunctions() == false) 244 { 245 if (log) 246 log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); 247 error.SetErrorString ("Not safe to call functions on this thread."); 248 return return_value; 249 } 250 251 // Set up the arguments for a call to 252 253 // struct get_current_queues_return_values 254 // { 255 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ 256 // uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ 257 // uint64_t count; /* the number of queues included in the queues buffer */ 258 // }; 259 // 260 // void 261 // __lldb_backtrace_recording_get_current_queues 262 // (struct get_current_queues_return_values *return_buffer, 263 // void *page_to_free, 264 // uint64_t page_to_free_size); 265 266 // Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in 267 // the inferior process. 268 269 CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 270 Value return_buffer_ptr_value; 271 return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar); 272 return_buffer_ptr_value.SetCompilerType (clang_void_ptr_type); 273 274 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 275 Value debug_value; 276 debug_value.SetValueType (Value::eValueTypeScalar); 277 debug_value.SetCompilerType (clang_int_type); 278 279 Value page_to_free_value; 280 page_to_free_value.SetValueType (Value::eValueTypeScalar); 281 page_to_free_value.SetCompilerType (clang_void_ptr_type); 282 283 CompilerType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 284 Value page_to_free_size_value; 285 page_to_free_size_value.SetValueType (Value::eValueTypeScalar); 286 page_to_free_size_value.SetCompilerType (clang_uint64_type); 287 288 289 Mutex::Locker locker(m_get_queues_retbuffer_mutex); 290 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) 291 { 292 addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); 293 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) 294 { 295 if (log) 296 log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); 297 return return_value; 298 } 299 m_get_queues_return_buffer_addr = bufaddr; 300 } 301 302 ValueList argument_values; 303 304 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; 305 argument_values.PushValue (return_buffer_ptr_value); 306 307 debug_value.GetScalar() = 0; 308 argument_values.PushValue (debug_value); 309 310 if (page_to_free != LLDB_INVALID_ADDRESS) 311 page_to_free_value.GetScalar() = page_to_free; 312 else 313 page_to_free_value.GetScalar() = 0; 314 argument_values.PushValue (page_to_free_value); 315 316 page_to_free_size_value.GetScalar() = page_to_free_size; 317 argument_values.PushValue (page_to_free_size_value); 318 319 addr_t args_addr = SetupGetQueuesFunction (thread, argument_values); 320 321 if (!m_get_queues_impl_code_up) 322 { 323 error.SetErrorString ("Unable to compile __introspection_dispatch_get_queues."); 324 return return_value; 325 } 326 327 FunctionCaller *get_queues_caller = m_get_queues_impl_code_up->GetFunctionCaller(); 328 329 if (get_queues_caller == NULL) 330 { 331 error.SetErrorString ("Unable to get caller for call __introspection_dispatch_get_queues"); 332 return return_value; 333 } 334 335 StreamString errors; 336 ExecutionContext exe_ctx; 337 EvaluateExpressionOptions options; 338 options.SetUnwindOnError (true); 339 options.SetIgnoreBreakpoints (true); 340 options.SetStopOthers (true); 341 options.SetTimeoutUsec(500000); 342 options.SetTryAllThreads (false); 343 thread.CalculateExecutionContext (exe_ctx); 344 345 ExpressionResults func_call_ret; 346 Value results; 347 func_call_ret = get_queues_caller->ExecuteFunction (exe_ctx, &args_addr, options, errors, results); 348 if (func_call_ret != eExpressionCompleted || !error.Success()) 349 { 350 if (log) 351 log->Printf ("Unable to call introspection_get_dispatch_queues(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); 352 error.SetErrorString ("Unable to call introspection_get_dispatch_queues() for list of queues"); 353 return return_value; 354 } 355 356 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); 357 if (!error.Success() || return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) 358 { 359 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 360 return return_value; 361 } 362 363 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 8, 8, 0, error); 364 365 if (!error.Success()) 366 { 367 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 368 return return_value; 369 } 370 371 return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 16, 8, 0, error); 372 if (!error.Success()) 373 { 374 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; 375 return return_value; 376 } 377 378 if (log) 379 log->Printf ("AppleGetQueuesHandler called __introspection_dispatch_get_queues (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.queues_buffer_ptr, return_value.queues_buffer_size, return_value.count); 380 381 return return_value; 382 } 383