1 //===-- AppleGetThreadItemInfoHandler.cpp -------------------------------*- C++ 2 //-*-===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "AppleGetThreadItemInfoHandler.h" 11 12 13 #include "lldb/Core/Module.h" 14 #include "lldb/Core/Value.h" 15 #include "lldb/Expression/DiagnosticManager.h" 16 #include "lldb/Expression/Expression.h" 17 #include "lldb/Expression/FunctionCaller.h" 18 #include "lldb/Expression/UtilityFunction.h" 19 #include "lldb/Symbol/ClangASTContext.h" 20 #include "lldb/Symbol/Symbol.h" 21 #include "lldb/Target/ExecutionContext.h" 22 #include "lldb/Target/Process.h" 23 #include "lldb/Target/StackFrame.h" 24 #include "lldb/Target/Target.h" 25 #include "lldb/Target/Thread.h" 26 #include "lldb/Utility/ConstString.h" 27 #include "lldb/Utility/Log.h" 28 #include "lldb/Utility/StreamString.h" 29 #include "lldb/lldb-private.h" 30 31 using namespace lldb; 32 using namespace lldb_private; 33 34 const char 35 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_name = 36 "__lldb_backtrace_recording_get_thread_item_info"; 37 const char 38 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_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 typedef void *pthread_t; \n\ 58 extern int printf(const char *format, ...); \n\ 59 extern pthread_t pthread_self(void); \n\ 60 \n\ 61 /* \n\ 62 * libBacktraceRecording defines \n\ 63 */ \n\ 64 \n\ 65 typedef uint32_t queue_list_scope_t; \n\ 66 typedef void *dispatch_queue_t; \n\ 67 typedef void *introspection_dispatch_queue_info_t; \n\ 68 typedef void *introspection_dispatch_item_info_ref; \n\ 69 \n\ 70 extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\ 71 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 72 uint64_t *returned_queues_buffer_size); \n\ 73 \n\ 74 /* \n\ 75 * return type define \n\ 76 */ \n\ 77 \n\ 78 struct get_thread_item_info_return_values \n\ 79 { \n\ 80 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 81 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 82 }; \n\ 83 \n\ 84 void __lldb_backtrace_recording_get_thread_item_info \n\ 85 (struct get_thread_item_info_return_values *return_buffer, \n\ 86 int debug, \n\ 87 uint64_t thread_id, \n\ 88 void *page_to_free, \n\ 89 uint64_t page_to_free_size) \n\ 90 { \n\ 91 void *pthread_id = pthread_self (); \n\ 92 if (debug) \n\ 93 printf (\"entering get_thread_item_info with args return_buffer == %p, debug == %d, thread id == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, (uint64_t) thread_id, page_to_free, page_to_free_size); \n\ 94 if (page_to_free != 0) \n\ 95 { \n\ 96 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 97 } \n\ 98 \n\ 99 __introspection_dispatch_thread_get_item_info (thread_id, \n\ 100 (void**)&return_buffer->item_info_buffer_ptr, \n\ 101 &return_buffer->item_info_buffer_size); \n\ 102 } \n\ 103 } \n\ 104 "; 105 106 AppleGetThreadItemInfoHandler::AppleGetThreadItemInfoHandler(Process *process) 107 : m_process(process), m_get_thread_item_info_impl_code(), 108 m_get_thread_item_info_function_mutex(), 109 m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS), 110 m_get_thread_item_info_retbuffer_mutex() {} 111 112 AppleGetThreadItemInfoHandler::~AppleGetThreadItemInfoHandler() {} 113 114 void AppleGetThreadItemInfoHandler::Detach() { 115 116 if (m_process && m_process->IsAlive() && 117 m_get_thread_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) { 118 std::unique_lock<std::mutex> lock(m_get_thread_item_info_retbuffer_mutex, 119 std::defer_lock); 120 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 121 m_process->DeallocateMemory(m_get_thread_item_info_return_buffer_addr); 122 } 123 } 124 125 // Compile our __lldb_backtrace_recording_get_thread_item_info() function (from 126 // the source above in g_get_thread_item_info_function_code) if we don't find 127 // that function in the inferior already with USE_BUILTIN_FUNCTION defined. 128 // (e.g. this would be the case for testing.) 129 // 130 // Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior 131 // process if needed. 132 // 133 // Write the get_thread_item_info_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 make the function call. 138 139 lldb::addr_t AppleGetThreadItemInfoHandler::SetupGetThreadItemInfoFunction( 140 Thread &thread, ValueList &get_thread_item_info_arglist) { 141 ThreadSP thread_sp(thread.shared_from_this()); 142 ExecutionContext exe_ctx(thread_sp); 143 Address impl_code_address; 144 DiagnosticManager diagnostics; 145 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 146 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 147 FunctionCaller *get_thread_item_info_caller = nullptr; 148 149 // Scope for mutex locker: 150 { 151 std::lock_guard<std::mutex> guard(m_get_thread_item_info_function_mutex); 152 153 // First stage is to make the ClangUtility to hold our injected function: 154 155 if (!m_get_thread_item_info_impl_code) { 156 Status error; 157 if (g_get_thread_item_info_function_code != NULL) { 158 m_get_thread_item_info_impl_code.reset( 159 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 160 g_get_thread_item_info_function_code, eLanguageTypeC, 161 g_get_thread_item_info_function_name, error)); 162 if (error.Fail()) { 163 if (log) 164 log->Printf("Failed to get UtilityFunction for " 165 "get-thread-item-info introspection: %s.", 166 error.AsCString()); 167 m_get_thread_item_info_impl_code.reset(); 168 return args_addr; 169 } 170 171 if (!m_get_thread_item_info_impl_code->Install(diagnostics, exe_ctx)) { 172 if (log) { 173 log->Printf( 174 "Failed to install get-thread-item-info introspection."); 175 diagnostics.Dump(log); 176 } 177 178 m_get_thread_item_info_impl_code.reset(); 179 return args_addr; 180 } 181 } else { 182 if (log) 183 log->Printf("No get-thread-item-info introspection code found."); 184 return LLDB_INVALID_ADDRESS; 185 } 186 187 // Also make the FunctionCaller for this UtilityFunction: 188 189 ClangASTContext *clang_ast_context = 190 thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 191 CompilerType get_thread_item_info_return_type = 192 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 193 194 get_thread_item_info_caller = 195 m_get_thread_item_info_impl_code->MakeFunctionCaller( 196 get_thread_item_info_return_type, get_thread_item_info_arglist, 197 thread_sp, error); 198 if (error.Fail() || get_thread_item_info_caller == nullptr) { 199 if (log) 200 log->Printf("Failed to install get-thread-item-info introspection " 201 "caller: %s.", 202 error.AsCString()); 203 m_get_thread_item_info_impl_code.reset(); 204 return args_addr; 205 } 206 207 } else { 208 get_thread_item_info_caller = 209 m_get_thread_item_info_impl_code->GetFunctionCaller(); 210 } 211 } 212 213 diagnostics.Clear(); 214 215 // Now write down the argument values for this particular call. This looks 216 // like it might be a race condition if other threads were calling into here, 217 // but actually it isn't because we allocate a new args structure for this 218 // call by passing args_addr = LLDB_INVALID_ADDRESS... 219 220 if (!get_thread_item_info_caller->WriteFunctionArguments( 221 exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) { 222 if (log) { 223 log->Printf("Error writing get-thread-item-info function arguments"); 224 diagnostics.Dump(log); 225 } 226 return args_addr; 227 } 228 229 return args_addr; 230 } 231 232 AppleGetThreadItemInfoHandler::GetThreadItemInfoReturnInfo 233 AppleGetThreadItemInfoHandler::GetThreadItemInfo(Thread &thread, 234 tid_t thread_id, 235 addr_t page_to_free, 236 uint64_t page_to_free_size, 237 Status &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 GetThreadItemInfoReturnInfo return_value; 245 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 246 return_value.item_buffer_size = 0; 247 248 error.Clear(); 249 250 if (!thread.SafeToCallFunctions()) { 251 if (log) 252 log->Printf("Not safe to call functions on thread 0x%" PRIx64, 253 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_thread_item_info_return_values { 261 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 262 // from libBacktraceRecording */ 263 // uint64_t item_info_buffer_size; /* the size of the items buffer from 264 // libBacktraceRecording */ 265 // }; 266 // 267 // void __lldb_backtrace_recording_get_thread_item_info 268 // (struct 269 // get_thread_item_info_return_values 270 // *return_buffer, 271 // int debug, 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 276 // already allocated by lldb in the inferior process. 277 278 CompilerType clang_void_ptr_type = 279 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 280 Value return_buffer_ptr_value; 281 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 282 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 283 284 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 285 Value debug_value; 286 debug_value.SetValueType(Value::eValueTypeScalar); 287 debug_value.SetCompilerType(clang_int_type); 288 289 CompilerType clang_uint64_type = 290 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 291 Value thread_id_value; 292 thread_id_value.SetValueType(Value::eValueTypeScalar); 293 thread_id_value.SetCompilerType(clang_uint64_type); 294 295 Value page_to_free_value; 296 page_to_free_value.SetValueType(Value::eValueTypeScalar); 297 page_to_free_value.SetCompilerType(clang_void_ptr_type); 298 299 Value page_to_free_size_value; 300 page_to_free_size_value.SetValueType(Value::eValueTypeScalar); 301 page_to_free_size_value.SetCompilerType(clang_uint64_type); 302 303 std::lock_guard<std::mutex> guard(m_get_thread_item_info_retbuffer_mutex); 304 if (m_get_thread_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 305 addr_t bufaddr = process_sp->AllocateMemory( 306 32, ePermissionsReadable | ePermissionsWritable, error); 307 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 308 if (log) 309 log->Printf("Failed to allocate memory for return buffer for get " 310 "current queues func call"); 311 return return_value; 312 } 313 m_get_thread_item_info_return_buffer_addr = bufaddr; 314 } 315 316 ValueList argument_values; 317 318 return_buffer_ptr_value.GetScalar() = 319 m_get_thread_item_info_return_buffer_addr; 320 argument_values.PushValue(return_buffer_ptr_value); 321 322 debug_value.GetScalar() = 0; 323 argument_values.PushValue(debug_value); 324 325 thread_id_value.GetScalar() = thread_id; 326 argument_values.PushValue(thread_id_value); 327 328 if (page_to_free != LLDB_INVALID_ADDRESS) 329 page_to_free_value.GetScalar() = page_to_free; 330 else 331 page_to_free_value.GetScalar() = 0; 332 argument_values.PushValue(page_to_free_value); 333 334 page_to_free_size_value.GetScalar() = page_to_free_size; 335 argument_values.PushValue(page_to_free_size_value); 336 337 addr_t args_addr = SetupGetThreadItemInfoFunction(thread, argument_values); 338 339 DiagnosticManager diagnostics; 340 ExecutionContext exe_ctx; 341 EvaluateExpressionOptions options; 342 FunctionCaller *get_thread_item_info_caller = nullptr; 343 344 options.SetUnwindOnError(true); 345 options.SetIgnoreBreakpoints(true); 346 options.SetStopOthers(true); 347 options.SetTimeout(std::chrono::milliseconds(500)); 348 options.SetTryAllThreads(false); 349 options.SetIsForUtilityExpr(true); 350 thread.CalculateExecutionContext(exe_ctx); 351 352 if (!m_get_thread_item_info_impl_code) { 353 error.SetErrorString("Unable to compile function to call " 354 "__introspection_dispatch_thread_get_item_info"); 355 return return_value; 356 } 357 358 get_thread_item_info_caller = 359 m_get_thread_item_info_impl_code->GetFunctionCaller(); 360 361 if (!get_thread_item_info_caller) { 362 error.SetErrorString("Unable to compile function caller for " 363 "__introspection_dispatch_thread_get_item_info"); 364 return return_value; 365 } 366 367 ExpressionResults func_call_ret; 368 Value results; 369 func_call_ret = get_thread_item_info_caller->ExecuteFunction( 370 exe_ctx, &args_addr, options, diagnostics, results); 371 if (func_call_ret != eExpressionCompleted || !error.Success()) { 372 if (log) 373 log->Printf("Unable to call " 374 "__introspection_dispatch_thread_get_item_info(), got " 375 "ExpressionResults %d, error contains %s", 376 func_call_ret, error.AsCString("")); 377 error.SetErrorString("Unable to call " 378 "__introspection_dispatch_thread_get_item_info() for " 379 "list of queues"); 380 return return_value; 381 } 382 383 return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( 384 m_get_thread_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, 385 error); 386 if (!error.Success() || 387 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { 388 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 389 return return_value; 390 } 391 392 return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( 393 m_get_thread_item_info_return_buffer_addr + 8, 8, 0, error); 394 395 if (!error.Success()) { 396 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 397 return return_value; 398 } 399 400 if (log) 401 log->Printf("AppleGetThreadItemInfoHandler called " 402 "__introspection_dispatch_thread_get_item_info (page_to_free " 403 "== 0x%" PRIx64 ", size = %" PRId64 404 "), returned page is at 0x%" PRIx64 ", size %" PRId64, 405 page_to_free, page_to_free_size, return_value.item_buffer_ptr, 406 return_value.item_buffer_size); 407 408 return return_value; 409 } 410