//===-- AppleGetThreadItemInfoHandler.cpp ---------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #include "AppleGetThreadItemInfoHandler.h" #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" #include "lldb/Core/Module.h" #include "lldb/Core/Value.h" #include "lldb/Expression/DiagnosticManager.h" #include "lldb/Expression/Expression.h" #include "lldb/Expression/FunctionCaller.h" #include "lldb/Expression/UtilityFunction.h" #include "lldb/Symbol/Symbol.h" #include "lldb/Target/ExecutionContext.h" #include "lldb/Target/Process.h" #include "lldb/Target/StackFrame.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" #include "lldb/Utility/ConstString.h" #include "lldb/Utility/Log.h" #include "lldb/Utility/StreamString.h" #include "lldb/lldb-private.h" using namespace lldb; using namespace lldb_private; const char *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_name = "__lldb_backtrace_recording_get_thread_item_info"; const char *AppleGetThreadItemInfoHandler::g_get_thread_item_info_function_code = " \n\ extern \"C\" \n\ { \n\ /* \n\ * mach defines \n\ */ \n\ \n\ typedef unsigned int uint32_t; \n\ typedef unsigned long long uint64_t; \n\ typedef uint32_t mach_port_t; \n\ typedef mach_port_t vm_map_t; \n\ typedef int kern_return_t; \n\ typedef uint64_t mach_vm_address_t; \n\ typedef uint64_t mach_vm_size_t; \n\ \n\ mach_port_t mach_task_self (); \n\ kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ \n\ typedef void *pthread_t; \n\ extern int printf(const char *format, ...); \n\ extern pthread_t pthread_self(void); \n\ \n\ /* \n\ * libBacktraceRecording defines \n\ */ \n\ \n\ typedef uint32_t queue_list_scope_t; \n\ typedef void *dispatch_queue_t; \n\ typedef void *introspection_dispatch_queue_info_t; \n\ typedef void *introspection_dispatch_item_info_ref; \n\ \n\ extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\ introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ uint64_t *returned_queues_buffer_size); \n\ \n\ /* \n\ * return type define \n\ */ \n\ \n\ struct get_thread_item_info_return_values \n\ { \n\ uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ }; \n\ \n\ void __lldb_backtrace_recording_get_thread_item_info \n\ (struct get_thread_item_info_return_values *return_buffer, \n\ int debug, \n\ uint64_t thread_id, \n\ void *page_to_free, \n\ uint64_t page_to_free_size) \n\ { \n\ void *pthread_id = pthread_self (); \n\ if (debug) \n\ 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\ if (page_to_free != 0) \n\ { \n\ mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ } \n\ \n\ __introspection_dispatch_thread_get_item_info (thread_id, \n\ (void**)&return_buffer->item_info_buffer_ptr, \n\ &return_buffer->item_info_buffer_size); \n\ } \n\ } \n\ "; AppleGetThreadItemInfoHandler::AppleGetThreadItemInfoHandler(Process *process) : m_process(process), m_get_thread_item_info_impl_code(), m_get_thread_item_info_function_mutex(), m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS), m_get_thread_item_info_retbuffer_mutex() {} AppleGetThreadItemInfoHandler::~AppleGetThreadItemInfoHandler() {} void AppleGetThreadItemInfoHandler::Detach() { if (m_process && m_process->IsAlive() && m_get_thread_item_info_return_buffer_addr != LLDB_INVALID_ADDRESS) { std::unique_lock lock(m_get_thread_item_info_retbuffer_mutex, std::defer_lock); (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer m_process->DeallocateMemory(m_get_thread_item_info_return_buffer_addr); } } // Compile our __lldb_backtrace_recording_get_thread_item_info() function (from // the source above in g_get_thread_item_info_function_code) if we don't find // that function in the inferior already with USE_BUILTIN_FUNCTION defined. // (e.g. this would be the case for testing.) // // Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior // process if needed. // // Write the get_thread_item_info_arglist into the inferior's memory space to // prepare for the call. // // Returns the address of the arguments written down in the inferior process, // which can be used to make the function call. lldb::addr_t AppleGetThreadItemInfoHandler::SetupGetThreadItemInfoFunction( Thread &thread, ValueList &get_thread_item_info_arglist) { ThreadSP thread_sp(thread.shared_from_this()); ExecutionContext exe_ctx(thread_sp); Address impl_code_address; DiagnosticManager diagnostics; Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; FunctionCaller *get_thread_item_info_caller = nullptr; // Scope for mutex locker: { std::lock_guard guard(m_get_thread_item_info_function_mutex); // First stage is to make the ClangUtility to hold our injected function: if (!m_get_thread_item_info_impl_code) { Status error; if (g_get_thread_item_info_function_code != nullptr) { auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction( g_get_thread_item_info_function_code, g_get_thread_item_info_function_name, eLanguageTypeC, exe_ctx); if (!utility_fn_or_error) { LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(), "Failed to get UtilityFunction for " "get-thread-item-info introspection: {0}."); return args_addr; } m_get_thread_item_info_impl_code = std::move(*utility_fn_or_error); } else { LLDB_LOGF(log, "No get-thread-item-info introspection code found."); return LLDB_INVALID_ADDRESS; } // Also make the FunctionCaller for this UtilityFunction: TypeSystemClang *clang_ast_context = ScratchTypeSystemClang::GetForTarget( thread.GetProcess()->GetTarget()); CompilerType get_thread_item_info_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); get_thread_item_info_caller = m_get_thread_item_info_impl_code->MakeFunctionCaller( get_thread_item_info_return_type, get_thread_item_info_arglist, thread_sp, error); if (error.Fail() || get_thread_item_info_caller == nullptr) { LLDB_LOGF(log, "Failed to install get-thread-item-info introspection " "caller: %s.", error.AsCString()); m_get_thread_item_info_impl_code.reset(); return args_addr; } } else { get_thread_item_info_caller = m_get_thread_item_info_impl_code->GetFunctionCaller(); } } diagnostics.Clear(); // Now write down the argument values for this particular call. This looks // like it might be a race condition if other threads were calling into here, // but actually it isn't because we allocate a new args structure for this // call by passing args_addr = LLDB_INVALID_ADDRESS... if (!get_thread_item_info_caller->WriteFunctionArguments( exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) { if (log) { LLDB_LOGF(log, "Error writing get-thread-item-info function arguments"); diagnostics.Dump(log); } return args_addr; } return args_addr; } AppleGetThreadItemInfoHandler::GetThreadItemInfoReturnInfo AppleGetThreadItemInfoHandler::GetThreadItemInfo(Thread &thread, tid_t thread_id, addr_t page_to_free, uint64_t page_to_free_size, Status &error) { lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); ProcessSP process_sp(thread.CalculateProcess()); TargetSP target_sp(thread.CalculateTarget()); TypeSystemClang *clang_ast_context = ScratchTypeSystemClang::GetForTarget(*target_sp); Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYSTEM_RUNTIME)); GetThreadItemInfoReturnInfo return_value; return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; return_value.item_buffer_size = 0; error.Clear(); if (!thread.SafeToCallFunctions()) { LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64, thread.GetID()); error.SetErrorString("Not safe to call functions on this thread."); return return_value; } // Set up the arguments for a call to // struct get_thread_item_info_return_values { // uint64_t item_info_buffer_ptr; /* the address of the items buffer // from libBacktraceRecording */ // uint64_t item_info_buffer_size; /* the size of the items buffer from // libBacktraceRecording */ // }; // // void __lldb_backtrace_recording_get_thread_item_info // (struct // get_thread_item_info_return_values // *return_buffer, // int debug, // void *page_to_free, // uint64_t page_to_free_size) // Where the return_buffer argument points to a 24 byte region of memory // already allocated by lldb in the inferior process. CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); Value return_buffer_ptr_value; return_buffer_ptr_value.SetValueType(Value::eValueTypeScalar); return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt); Value debug_value; debug_value.SetValueType(Value::eValueTypeScalar); debug_value.SetCompilerType(clang_int_type); CompilerType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong); Value thread_id_value; thread_id_value.SetValueType(Value::eValueTypeScalar); thread_id_value.SetCompilerType(clang_uint64_type); Value page_to_free_value; page_to_free_value.SetValueType(Value::eValueTypeScalar); page_to_free_value.SetCompilerType(clang_void_ptr_type); Value page_to_free_size_value; page_to_free_size_value.SetValueType(Value::eValueTypeScalar); page_to_free_size_value.SetCompilerType(clang_uint64_type); std::lock_guard guard(m_get_thread_item_info_retbuffer_mutex); if (m_get_thread_item_info_return_buffer_addr == LLDB_INVALID_ADDRESS) { addr_t bufaddr = process_sp->AllocateMemory( 32, ePermissionsReadable | ePermissionsWritable, error); if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { LLDB_LOGF(log, "Failed to allocate memory for return buffer for get " "current queues func call"); return return_value; } m_get_thread_item_info_return_buffer_addr = bufaddr; } ValueList argument_values; return_buffer_ptr_value.GetScalar() = m_get_thread_item_info_return_buffer_addr; argument_values.PushValue(return_buffer_ptr_value); debug_value.GetScalar() = 0; argument_values.PushValue(debug_value); thread_id_value.GetScalar() = thread_id; argument_values.PushValue(thread_id_value); if (page_to_free != LLDB_INVALID_ADDRESS) page_to_free_value.GetScalar() = page_to_free; else page_to_free_value.GetScalar() = 0; argument_values.PushValue(page_to_free_value); page_to_free_size_value.GetScalar() = page_to_free_size; argument_values.PushValue(page_to_free_size_value); addr_t args_addr = SetupGetThreadItemInfoFunction(thread, argument_values); DiagnosticManager diagnostics; ExecutionContext exe_ctx; EvaluateExpressionOptions options; FunctionCaller *get_thread_item_info_caller = nullptr; options.SetUnwindOnError(true); options.SetIgnoreBreakpoints(true); options.SetStopOthers(true); #if __has_feature(address_sanitizer) options.SetTimeout(process_sp->GetUtilityExpressionTimeout()); #else options.SetTimeout(std::chrono::milliseconds(500)); #endif options.SetTryAllThreads(false); options.SetIsForUtilityExpr(true); thread.CalculateExecutionContext(exe_ctx); if (!m_get_thread_item_info_impl_code) { error.SetErrorString("Unable to compile function to call " "__introspection_dispatch_thread_get_item_info"); return return_value; } get_thread_item_info_caller = m_get_thread_item_info_impl_code->GetFunctionCaller(); if (!get_thread_item_info_caller) { error.SetErrorString("Unable to compile function caller for " "__introspection_dispatch_thread_get_item_info"); return return_value; } ExpressionResults func_call_ret; Value results; func_call_ret = get_thread_item_info_caller->ExecuteFunction( exe_ctx, &args_addr, options, diagnostics, results); if (func_call_ret != eExpressionCompleted || !error.Success()) { LLDB_LOGF(log, "Unable to call " "__introspection_dispatch_thread_get_item_info(), got " "ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); error.SetErrorString("Unable to call " "__introspection_dispatch_thread_get_item_info() for " "list of queues"); return return_value; } return_value.item_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( m_get_thread_item_info_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); if (!error.Success() || return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) { return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; return return_value; } return_value.item_buffer_size = m_process->ReadUnsignedIntegerFromMemory( m_get_thread_item_info_return_buffer_addr + 8, 8, 0, error); if (!error.Success()) { return_value.item_buffer_ptr = LLDB_INVALID_ADDRESS; return return_value; } LLDB_LOGF(log, "AppleGetThreadItemInfoHandler called " "__introspection_dispatch_thread_get_item_info (page_to_free " "== 0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64 ", size %" PRId64, page_to_free, page_to_free_size, return_value.item_buffer_ptr, return_value.item_buffer_size); return return_value; }