396 lines · cpp
1//===-- AppleGetQueuesHandler.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "AppleGetQueuesHandler.h"10 11#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"12#include "lldb/Core/Module.h"13#include "lldb/Core/Value.h"14#include "lldb/Expression/DiagnosticManager.h"15#include "lldb/Expression/FunctionCaller.h"16#include "lldb/Expression/UtilityFunction.h"17#include "lldb/Symbol/Symbol.h"18#include "lldb/Target/ExecutionContext.h"19#include "lldb/Target/Process.h"20#include "lldb/Target/Target.h"21#include "lldb/Target/Thread.h"22#include "lldb/Utility/ConstString.h"23#include "lldb/Utility/LLDBLog.h"24#include "lldb/Utility/Log.h"25#include "lldb/Utility/StreamString.h"26 27using namespace lldb;28using namespace lldb_private;29 30const char *AppleGetQueuesHandler::g_get_current_queues_function_name =31 "__lldb_backtrace_recording_get_current_queues";32const char *AppleGetQueuesHandler::g_get_current_queues_function_code =33 " \n\34extern \"C\" \n\35{ \n\36 /* \n\37 * mach defines \n\38 */ \n\39 \n\40 typedef unsigned int uint32_t; \n\41 typedef unsigned long long uint64_t; \n\42 typedef uint32_t mach_port_t; \n\43 typedef mach_port_t vm_map_t; \n\44 typedef int kern_return_t; \n\45 typedef uint64_t mach_vm_address_t; \n\46 typedef uint64_t mach_vm_size_t; \n\47 \n\48 mach_port_t mach_task_self (); \n\49 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\50 \n\51 /* \n\52 * libBacktraceRecording defines \n\53 */ \n\54 \n\55 typedef uint32_t queue_list_scope_t; \n\56 typedef void *introspection_dispatch_queue_info_t; \n\57 \n\58 extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\59 introspection_dispatch_queue_info_t *returned_queues_buffer, \n\60 uint64_t *returned_queues_buffer_size); \n\61 extern int printf(const char *format, ...); \n\62 \n\63 /* \n\64 * return type define \n\65 */ \n\66 \n\67 struct get_current_queues_return_values \n\68 { \n\69 uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\70 uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\71 uint64_t count; /* the number of queues included in the queues buffer */ \n\72 }; \n\73 \n\74 void __lldb_backtrace_recording_get_current_queues \n\75 (struct get_current_queues_return_values *return_buffer, \n\76 int debug, \n\77 void *page_to_free, \n\78 uint64_t page_to_free_size) \n\79{ \n\80 if (debug) \n\81 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\82 if (page_to_free != 0) \n\83 { \n\84 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\85 } \n\86 \n\87 return_buffer->count = __introspection_dispatch_get_queues ( \n\88 /* QUEUES_WITH_ANY_ITEMS */ 2, \n\89 (void**)&return_buffer->queues_buffer_ptr, \n\90 &return_buffer->queues_buffer_size); \n\91 if (debug) \n\92 printf(\"result was count %lld\\n\", return_buffer->count); \n\93} \n\94} \n\95";96 97AppleGetQueuesHandler::AppleGetQueuesHandler(Process *process)98 : m_process(process), m_get_queues_impl_code_up(),99 m_get_queues_function_mutex(),100 m_get_queues_return_buffer_addr(LLDB_INVALID_ADDRESS),101 m_get_queues_retbuffer_mutex() {}102 103AppleGetQueuesHandler::~AppleGetQueuesHandler() = default;104 105void AppleGetQueuesHandler::Detach() {106 107 if (m_process && m_process->IsAlive() &&108 m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) {109 std::unique_lock<std::mutex> lock(m_get_queues_retbuffer_mutex,110 std::defer_lock);111 (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer112 m_process->DeallocateMemory(m_get_queues_return_buffer_addr);113 }114}115 116// Construct a CompilerType for the structure that117// g_get_current_queues_function_code will return by value so we can extract118// the fields after performing the function call. i.e. we are getting this119// struct returned to us:120//121// struct get_current_queues_return_values122// {123// introspection_dispatch_queue_info_t *queues_buffer;124// uint64_t queues_buffer_size;125// uint64_t count;126// };127 128// Compile our __lldb_backtrace_recording_get_current_queues() function (from129// the source above in g_get_current_queues_function_code) if we don't find130// that function in the inferior already with USE_BUILTIN_FUNCTION defined.131// (e.g. this would be the case for testing.)132//133// Insert the __lldb_backtrace_recording_get_current_queues into the inferior134// process if needed.135//136// Write the get_queues_arglist into the inferior's memory space to prepare for137// the call.138//139// Returns the address of the arguments written down in the inferior process,140// which can be used to make the function call.141 142lldb::addr_t143AppleGetQueuesHandler::SetupGetQueuesFunction(Thread &thread,144 ValueList &get_queues_arglist) {145 ThreadSP thread_sp(thread.shared_from_this());146 ExecutionContext exe_ctx(thread_sp);147 148 Address impl_code_address;149 DiagnosticManager diagnostics;150 Log *log = GetLog(LLDBLog::SystemRuntime);151 lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;152 153 FunctionCaller *get_queues_caller = nullptr;154 155 // Scope for mutex locker:156 {157 std::lock_guard<std::mutex> guard(m_get_queues_function_mutex);158 159 // First stage is to make the ClangUtility to hold our injected function:160 161 if (!m_get_queues_impl_code_up) {162 if (g_get_current_queues_function_code != nullptr) {163 auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction(164 g_get_current_queues_function_code,165 g_get_current_queues_function_name, eLanguageTypeC, exe_ctx);166 if (!utility_fn_or_error) {167 LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(),168 "Failed to create UtilityFunction for queues "169 "introspection: {0}.");170 return args_addr;171 }172 m_get_queues_impl_code_up = std::move(*utility_fn_or_error);173 } else {174 if (log) {175 LLDB_LOGF(log, "No queues introspection code found.");176 diagnostics.Dump(log);177 }178 return LLDB_INVALID_ADDRESS;179 }180 }181 182 // Next make the runner function for our implementation utility function.183 TypeSystemClangSP scratch_ts_sp =184 ScratchTypeSystemClang::GetForTarget(thread.GetProcess()->GetTarget());185 CompilerType get_queues_return_type =186 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();187 Status error;188 get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller(189 get_queues_return_type, get_queues_arglist, thread_sp, error);190 if (error.Fail() || get_queues_caller == nullptr) {191 LLDB_LOGF(log,192 "Could not get function caller for get-queues function: %s.",193 error.AsCString());194 return args_addr;195 }196 }197 198 diagnostics.Clear();199 200 // Now write down the argument values for this particular call. This looks201 // like it might be a race condition if other threads were calling into here,202 // but actually it isn't because we allocate a new args structure for this203 // call by passing args_addr = LLDB_INVALID_ADDRESS...204 205 if (!get_queues_caller->WriteFunctionArguments(206 exe_ctx, args_addr, get_queues_arglist, diagnostics)) {207 if (log) {208 LLDB_LOGF(log, "Error writing get-queues function arguments.");209 diagnostics.Dump(log);210 }211 return args_addr;212 }213 214 return args_addr;215}216 217AppleGetQueuesHandler::GetQueuesReturnInfo218AppleGetQueuesHandler::GetCurrentQueues(Thread &thread, addr_t page_to_free,219 uint64_t page_to_free_size,220 Status &error) {221 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);222 ProcessSP process_sp(thread.CalculateProcess());223 TargetSP target_sp(thread.CalculateTarget());224 TypeSystemClangSP scratch_ts_sp =225 ScratchTypeSystemClang::GetForTarget(*target_sp);226 Log *log = GetLog(LLDBLog::SystemRuntime);227 228 GetQueuesReturnInfo return_value;229 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;230 return_value.queues_buffer_size = 0;231 return_value.count = 0;232 233 error.Clear();234 235 if (!thread.SafeToCallFunctions()) {236 LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64,237 thread.GetID());238 error =239 Status::FromErrorString("Not safe to call functions on this thread.");240 return return_value;241 }242 243 // Set up the arguments for a call to244 245 // struct get_current_queues_return_values246 // {247 // uint64_t queues_buffer_ptr; /* the address of the queues buffer from248 // libBacktraceRecording */249 // uint64_t queues_buffer_size; /* the size of the queues buffer from250 // libBacktraceRecording */251 // uint64_t count; /* the number of queues included in the252 // queues buffer */253 // };254 //255 // void256 // __lldb_backtrace_recording_get_current_queues257 // (struct258 // get_current_queues_return_values259 // *return_buffer,260 // void *page_to_free,261 // uint64_t page_to_free_size);262 263 // Where the return_buffer argument points to a 24 byte region of memory264 // already allocated by lldb in the inferior process.265 266 CompilerType clang_void_ptr_type =267 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();268 Value return_buffer_ptr_value;269 return_buffer_ptr_value.SetValueType(Value::ValueType::Scalar);270 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type);271 272 CompilerType clang_int_type = scratch_ts_sp->GetBasicType(eBasicTypeInt);273 Value debug_value;274 debug_value.SetValueType(Value::ValueType::Scalar);275 debug_value.SetCompilerType(clang_int_type);276 277 Value page_to_free_value;278 page_to_free_value.SetValueType(Value::ValueType::Scalar);279 page_to_free_value.SetCompilerType(clang_void_ptr_type);280 281 CompilerType clang_uint64_type =282 scratch_ts_sp->GetBasicType(eBasicTypeUnsignedLongLong);283 Value page_to_free_size_value;284 page_to_free_size_value.SetValueType(Value::ValueType::Scalar);285 page_to_free_size_value.SetCompilerType(clang_uint64_type);286 287 std::lock_guard<std::mutex> guard(m_get_queues_retbuffer_mutex);288 if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) {289 addr_t bufaddr = process_sp->AllocateMemory(290 32, ePermissionsReadable | ePermissionsWritable, error);291 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) {292 LLDB_LOGF(log, "Failed to allocate memory for return buffer for get "293 "current queues func call");294 return return_value;295 }296 m_get_queues_return_buffer_addr = bufaddr;297 }298 299 ValueList argument_values;300 301 return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr;302 argument_values.PushValue(return_buffer_ptr_value);303 304 debug_value.GetScalar() = 0;305 argument_values.PushValue(debug_value);306 307 if (page_to_free != LLDB_INVALID_ADDRESS)308 page_to_free_value.GetScalar() = page_to_free;309 else310 page_to_free_value.GetScalar() = 0;311 argument_values.PushValue(page_to_free_value);312 313 page_to_free_size_value.GetScalar() = page_to_free_size;314 argument_values.PushValue(page_to_free_size_value);315 316 addr_t args_addr = SetupGetQueuesFunction(thread, argument_values);317 318 if (!m_get_queues_impl_code_up) {319 error = Status::FromErrorString(320 "Unable to compile __introspection_dispatch_get_queues.");321 return return_value;322 }323 324 FunctionCaller *get_queues_caller =325 m_get_queues_impl_code_up->GetFunctionCaller();326 327 if (get_queues_caller == nullptr) {328 error = Status::FromErrorString(329 "Unable to get caller for call __introspection_dispatch_get_queues");330 return return_value;331 }332 333 DiagnosticManager diagnostics;334 ExecutionContext exe_ctx;335 EvaluateExpressionOptions options;336 options.SetUnwindOnError(true);337 options.SetIgnoreBreakpoints(true);338 options.SetStopOthers(true);339#if __has_feature(address_sanitizer)340 options.SetTimeout(process_sp->GetUtilityExpressionTimeout());341#else342 options.SetTimeout(std::chrono::milliseconds(500));343#endif344 options.SetTryAllThreads(false);345 options.SetIsForUtilityExpr(true);346 thread.CalculateExecutionContext(exe_ctx);347 348 ExpressionResults func_call_ret;349 Value results;350 func_call_ret = get_queues_caller->ExecuteFunction(351 exe_ctx, &args_addr, options, diagnostics, results);352 if (func_call_ret != eExpressionCompleted || !error.Success()) {353 LLDB_LOGF(log,354 "Unable to call introspection_get_dispatch_queues(), got "355 "ExpressionResults %d, error contains %s",356 func_call_ret, error.AsCString(""));357 error = Status::FromErrorString(358 "Unable to call introspection_get_dispatch_queues() "359 "for list of queues");360 return return_value;361 }362 363 return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory(364 m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error);365 if (!error.Success() ||366 return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) {367 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;368 return return_value;369 }370 371 return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory(372 m_get_queues_return_buffer_addr + 8, 8, 0, error);373 374 if (!error.Success()) {375 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;376 return return_value;377 }378 379 return_value.count = m_process->ReadUnsignedIntegerFromMemory(380 m_get_queues_return_buffer_addr + 16, 8, 0, error);381 if (!error.Success()) {382 return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;383 return return_value;384 }385 386 LLDB_LOGF(log,387 "AppleGetQueuesHandler called "388 "__introspection_dispatch_get_queues (page_to_free == "389 "0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64390 ", size %" PRId64 ", count = %" PRId64,391 page_to_free, page_to_free_size, return_value.queues_buffer_ptr,392 return_value.queues_buffer_size, return_value.count);393 394 return return_value;395}396