1 //===-- AppleGetThreadItemInfoHandler.cpp ---------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "AppleGetThreadItemInfoHandler.h" 10 11 12 #include "lldb/Core/Module.h" 13 #include "lldb/Core/Value.h" 14 #include "lldb/Expression/DiagnosticManager.h" 15 #include "lldb/Expression/Expression.h" 16 #include "lldb/Expression/FunctionCaller.h" 17 #include "lldb/Expression/UtilityFunction.h" 18 #include "lldb/Symbol/TypeSystemClang.h" 19 #include "lldb/Symbol/Symbol.h" 20 #include "lldb/Target/ExecutionContext.h" 21 #include "lldb/Target/Process.h" 22 #include "lldb/Target/StackFrame.h" 23 #include "lldb/Target/Target.h" 24 #include "lldb/Target/Thread.h" 25 #include "lldb/Utility/ConstString.h" 26 #include "lldb/Utility/Log.h" 27 #include "lldb/Utility/StreamString.h" 28 #include "lldb/lldb-private.h" 29 30 using namespace lldb; 31 using namespace lldb_private; 32 33 const char 34 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_name = 35 "__lldb_backtrace_recording_get_thread_item_info"; 36 const char 37 *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_code = 38 " \n\ 39 extern \"C\" \n\ 40 { \n\ 41 /* \n\ 42 * mach defines \n\ 43 */ \n\ 44 \n\ 45 typedef unsigned int uint32_t; \n\ 46 typedef unsigned long long uint64_t; \n\ 47 typedef uint32_t mach_port_t; \n\ 48 typedef mach_port_t vm_map_t; \n\ 49 typedef int kern_return_t; \n\ 50 typedef uint64_t mach_vm_address_t; \n\ 51 typedef uint64_t mach_vm_size_t; \n\ 52 \n\ 53 mach_port_t mach_task_self (); \n\ 54 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ 55 \n\ 56 typedef void *pthread_t; \n\ 57 extern int printf(const char *format, ...); \n\ 58 extern pthread_t pthread_self(void); \n\ 59 \n\ 60 /* \n\ 61 * libBacktraceRecording defines \n\ 62 */ \n\ 63 \n\ 64 typedef uint32_t queue_list_scope_t; \n\ 65 typedef void *dispatch_queue_t; \n\ 66 typedef void *introspection_dispatch_queue_info_t; \n\ 67 typedef void *introspection_dispatch_item_info_ref; \n\ 68 \n\ 69 extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\ 70 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ 71 uint64_t *returned_queues_buffer_size); \n\ 72 \n\ 73 /* \n\ 74 * return type define \n\ 75 */ \n\ 76 \n\ 77 struct get_thread_item_info_return_values \n\ 78 { \n\ 79 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ 80 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ 81 }; \n\ 82 \n\ 83 void __lldb_backtrace_recording_get_thread_item_info \n\ 84 (struct get_thread_item_info_return_values *return_buffer, \n\ 85 int debug, \n\ 86 uint64_t thread_id, \n\ 87 void *page_to_free, \n\ 88 uint64_t page_to_free_size) \n\ 89 { \n\ 90 void *pthread_id = pthread_self (); \n\ 91 if (debug) \n\ 92 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\ 93 if (page_to_free != 0) \n\ 94 { \n\ 95 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ 96 } \n\ 97 \n\ 98 __introspection_dispatch_thread_get_item_info (thread_id, \n\ 99 (void**)&return_buffer->item_info_buffer_ptr, \n\ 100 &return_buffer->item_info_buffer_size); \n\ 101 } \n\ 102 } \n\ 103 "; 104 105 AppleGetThreadItemInfoHandler::AppleGetThreadItemInfoHandler(Process *process) 106 : m_process(process), m_get_thread_item_info_impl_code(), 107 m_get_thread_item_info_function_mutex(), 108 m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS), 109 m_get_thread_item_info_retbuffer_mutex() {} 110 111 AppleGetThreadItemInfoHandler::~AppleGetThreadItemInfoHandler() {} 112 113 void AppleGetThreadItemInfoHandler::Detach() { 114 115 if (m_process && m_process->IsAlive() && 116 m_get_thread_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) { 117 std::unique_lock<std::mutex> lock(m_get_thread_item_info_retbuffer_mutex, 118 std::defer_lock); 119 lock.try_lock(); // Even if we don't get the lock, deallocate the buffer 120 m_process->DeallocateMemory(m_get_thread_item_info_return_buffer_addr); 121 } 122 } 123 124 // Compile our __lldb_backtrace_recording_get_thread_item_info() function (from 125 // the source above in g_get_thread_item_info_function_code) if we don't find 126 // that function in the inferior already with USE_BUILTIN_FUNCTION defined. 127 // (e.g. this would be the case for testing.) 128 // 129 // Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior 130 // process if needed. 131 // 132 // Write the get_thread_item_info_arglist into the inferior's memory space to 133 // prepare for the call. 134 // 135 // Returns the address of the arguments written down in the inferior process, 136 // which can be used to make the function call. 137 138 lldb::addr_t AppleGetThreadItemInfoHandler::SetupGetThreadItemInfoFunction( 139 Thread &thread, ValueList &get_thread_item_info_arglist) { 140 ThreadSP thread_sp(thread.shared_from_this()); 141 ExecutionContext exe_ctx(thread_sp); 142 Address impl_code_address; 143 DiagnosticManager diagnostics; 144 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 145 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 146 FunctionCaller *get_thread_item_info_caller = nullptr; 147 148 // Scope for mutex locker: 149 { 150 std::lock_guard<std::mutex> guard(m_get_thread_item_info_function_mutex); 151 152 // First stage is to make the ClangUtility to hold our injected function: 153 154 if (!m_get_thread_item_info_impl_code) { 155 Status error; 156 if (g_get_thread_item_info_function_code != nullptr) { 157 m_get_thread_item_info_impl_code.reset( 158 exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 159 g_get_thread_item_info_function_code, eLanguageTypeC, 160 g_get_thread_item_info_function_name, error)); 161 if (error.Fail()) { 162 LLDB_LOGF(log, 163 "Failed to get UtilityFunction for " 164 "get-thread-item-info introspection: %s.", 165 error.AsCString()); 166 m_get_thread_item_info_impl_code.reset(); 167 return args_addr; 168 } 169 170 if (!m_get_thread_item_info_impl_code->Install(diagnostics, exe_ctx)) { 171 if (log) { 172 LLDB_LOGF(log, 173 "Failed to install get-thread-item-info introspection."); 174 diagnostics.Dump(log); 175 } 176 177 m_get_thread_item_info_impl_code.reset(); 178 return args_addr; 179 } 180 } else { 181 LLDB_LOGF(log, "No get-thread-item-info introspection code found."); 182 return LLDB_INVALID_ADDRESS; 183 } 184 185 // Also make the FunctionCaller for this UtilityFunction: 186 187 TypeSystemClang *clang_ast_context = 188 TypeSystemClang::GetScratch(thread.GetProcess()->GetTarget()); 189 CompilerType get_thread_item_info_return_type = 190 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 191 192 get_thread_item_info_caller = 193 m_get_thread_item_info_impl_code->MakeFunctionCaller( 194 get_thread_item_info_return_type, get_thread_item_info_arglist, 195 thread_sp, error); 196 if (error.Fail() || get_thread_item_info_caller == nullptr) { 197 LLDB_LOGF(log, 198 "Failed to install get-thread-item-info introspection " 199 "caller: %s.", 200 error.AsCString()); 201 m_get_thread_item_info_impl_code.reset(); 202 return args_addr; 203 } 204 205 } else { 206 get_thread_item_info_caller = 207 m_get_thread_item_info_impl_code->GetFunctionCaller(); 208 } 209 } 210 211 diagnostics.Clear(); 212 213 // Now write down the argument values for this particular call. This looks 214 // like it might be a race condition if other threads were calling into here, 215 // but actually it isn't because we allocate a new args structure for this 216 // call by passing args_addr = LLDB_INVALID_ADDRESS... 217 218 if (!get_thread_item_info_caller->WriteFunctionArguments( 219 exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) { 220 if (log) { 221 LLDB_LOGF(log, "Error writing get-thread-item-info function arguments"); 222 diagnostics.Dump(log); 223 } 224 return args_addr; 225 } 226 227 return args_addr; 228 } 229 230 AppleGetThreadItemInfoHandler::GetThreadItemInfoReturnInfo 231 AppleGetThreadItemInfoHandler::GetThreadItemInfo(Thread &thread, 232 tid_t thread_id, 233 addr_t page_to_free, 234 uint64_t page_to_free_size, 235 Status &error) { 236 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 237 ProcessSP process_sp(thread.CalculateProcess()); 238 TargetSP target_sp(thread.CalculateTarget()); 239 TypeSystemClang *clang_ast_context = TypeSystemClang::GetScratch(*target_sp); 240 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); 241 242 GetThreadItemInfoReturnInfo return_value; 243 return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; 244 return_value.item_buffer_size = 0; 245 246 error.Clear(); 247 248 if (!thread.SafeToCallFunctions()) { 249 LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64, 250 thread.GetID()); 251 error.SetErrorString("Not safe to call functions on this thread."); 252 return return_value; 253 } 254 255 // Set up the arguments for a call to 256 257 // struct get_thread_item_info_return_values { 258 // uint64_t item_info_buffer_ptr; /* the address of the items buffer 259 // from libBacktraceRecording */ 260 // uint64_t item_info_buffer_size; /* the size of the items buffer from 261 // libBacktraceRecording */ 262 // }; 263 // 264 // void __lldb_backtrace_recording_get_thread_item_info 265 // (struct 266 // get_thread_item_info_return_values 267 // *return_buffer, 268 // int debug, 269 // void *page_to_free, 270 // uint64_t page_to_free_size) 271 272 // Where the return_buffer argument points to a 24 byte region of memory 273 // already allocated by lldb in the inferior process. 274 275 CompilerType clang_void_ptr_type = 276 clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 277 Value return_buffer_ptr_value; 278 return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); 279 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); 280 281 CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); 282 Value debug_value; 283 debug_value.SetValueType(Value::eValueTypeScalar); 284 debug_value.SetCompilerType(clang_int_type); 285 286 CompilerType clang_uint64_type = 287 clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); 288 Value thread_id_value; 289 thread_id_value.SetValueType(Value::eValueTypeScalar); 290 thread_id_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_thread_item_info_retbuffer_mutex); 301 if (m_get_thread_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { 302 addr_t bufaddr = process_sp->AllocateMemory( 303 32, ePermissionsReadable | ePermissionsWritable, error); 304 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { 305 LLDB_LOGF(log, "Failed to allocate memory for return buffer for get " 306 "current queues func call"); 307 return return_value; 308 } 309 m_get_thread_item_info_return_buffer_addr = bufaddr; 310 } 311 312 ValueList argument_values; 313 314 return_buffer_ptr_value.GetScalar() = 315 m_get_thread_item_info_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 thread_id_value.GetScalar() = thread_id; 322 argument_values.PushValue(thread_id_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 = SetupGetThreadItemInfoFunction(thread, argument_values); 334 335 DiagnosticManager diagnostics; 336 ExecutionContext exe_ctx; 337 EvaluateExpressionOptions options; 338 FunctionCaller *get_thread_item_info_caller = nullptr; 339 340 options.SetUnwindOnError(true); 341 options.SetIgnoreBreakpoints(true); 342 options.SetStopOthers(true); 343 #if __has_feature(address_sanitizer) 344 options.SetTimeout(process_sp->GetUtilityExpressionTimeout()); 345 #else 346 options.SetTimeout(std::chrono::milliseconds(500)); 347 #endif 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 LLDB_LOGF(log, 373 "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 LLDB_LOGF(log, 401 "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