//===-- AppleGetPendingItemsHandler.cpp -------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "AppleGetPendingItemsHandler.h" // C Includes // C++ Includes // Other libraries and framework includes // Project includes #include "lldb/Core/ConstString.h" #include "lldb/Core/Log.h" #include "lldb/Core/Module.h" #include "lldb/Core/StreamString.h" #include "lldb/Core/Value.h" #include "lldb/Expression/FunctionCaller.h" #include "lldb/Expression/UtilityFunction.h" #include "lldb/Symbol/ClangASTContext.h" #include "lldb/Symbol/Symbol.h" #include "lldb/Target/ExecutionContext.h" #include "lldb/Target/Process.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" using namespace lldb; using namespace lldb_private; const char *AppleGetPendingItemsHandler::g_get_pending_items_function_name = "__lldb_backtrace_recording_get_pending_items"; const char *AppleGetPendingItemsHandler::g_get_pending_items_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\ /* \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 uint64_t __introspection_dispatch_queue_get_pending_items (dispatch_queue_t queue, \n\ introspection_dispatch_item_info_ref *returned_queues_buffer, \n\ uint64_t *returned_queues_buffer_size); \n\ extern int printf(const char *format, ...); \n\ \n\ /* \n\ * return type define \n\ */ \n\ \n\ struct get_pending_items_return_values \n\ { \n\ uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\ uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\ uint64_t count; /* the number of items included in the queues buffer */ \n\ }; \n\ \n\ void __lldb_backtrace_recording_get_pending_items \n\ (struct get_pending_items_return_values *return_buffer, \n\ int debug, \n\ uint64_t /* dispatch_queue_t */ queue, \n\ void *page_to_free, \n\ uint64_t page_to_free_size) \n\ { \n\ if (debug) \n\ printf (\"entering get_pending_items with args return_buffer == %p, debug == %d, queue == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, queue, 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\ return_buffer->count = __introspection_dispatch_queue_get_pending_items ( \n\ (void*) queue, \n\ (void**)&return_buffer->pending_items_buffer_ptr, \n\ &return_buffer->pending_items_buffer_size); \n\ if (debug) \n\ printf(\"result was count %lld\\n\", return_buffer->count); \n\ } \n\ } \n\ "; AppleGetPendingItemsHandler::AppleGetPendingItemsHandler (Process *process) : m_process (process), m_get_pending_items_impl_code (), m_get_pending_items_function_mutex(), m_get_pending_items_return_buffer_addr (LLDB_INVALID_ADDRESS), m_get_pending_items_retbuffer_mutex() { } AppleGetPendingItemsHandler::~AppleGetPendingItemsHandler () { } void AppleGetPendingItemsHandler::Detach () { if (m_process && m_process->IsAlive() && m_get_pending_items_return_buffer_addr != LLDB_INVALID_ADDRESS) { Mutex::Locker locker; locker.TryLock (m_get_pending_items_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer m_process->DeallocateMemory (m_get_pending_items_return_buffer_addr); } } // Compile our __lldb_backtrace_recording_get_pending_items() function (from the // source above in g_get_pending_items_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_pending_items into the inferior process if needed. // // Write the get_pending_items_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 AppleGetPendingItemsHandler::SetupGetPendingItemsFunction (Thread &thread, ValueList &get_pending_items_arglist) { ExecutionContext exe_ctx (thread.shared_from_this()); StreamString errors; Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; FunctionCaller *get_pending_items_caller = nullptr; // Scope for mutex locker: { Mutex::Locker locker(m_get_pending_items_function_mutex); // First stage is to make the ClangUtility to hold our injected function: if (!m_get_pending_items_impl_code.get()) { if (g_get_pending_items_function_code != NULL) { Error error; m_get_pending_items_impl_code.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_pending_items_function_code, eLanguageTypeObjC, g_get_pending_items_function_name, error)); if (error.Fail()) { if (log) log->Printf ("Failed to get UtilityFunction for pending-items introspection: %s.", error.AsCString()); return args_addr; } if (!m_get_pending_items_impl_code->Install(errors, exe_ctx)) { if (log) log->Printf ("Failed to install pending-items introspection: %s.", errors.GetData()); m_get_pending_items_impl_code.reset(); return args_addr; } } else { if (log) log->Printf("No pending-items introspection code found."); return LLDB_INVALID_ADDRESS; } // Next make the runner function for our implementation utility function. Error error; ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); CompilerType get_pending_items_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); get_pending_items_caller = m_get_pending_items_impl_code->MakeFunctionCaller (get_pending_items_return_type, get_pending_items_arglist, error); if (error.Fail()) { if (log) log->Printf ("Failed to install pending-items introspection function caller: %s.", error.AsCString()); m_get_pending_items_impl_code.reset(); return args_addr; } } } errors.Clear(); if (get_pending_items_caller == nullptr) { if (log) log->Printf ("Failed to get get_pending_items_caller."); return LLDB_INVALID_ADDRESS; } // 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_pending_items_caller->WriteFunctionArguments (exe_ctx, args_addr, get_pending_items_arglist, errors)) { if (log) log->Printf ("Error writing pending-items function arguments: \"%s\".", errors.GetData()); return args_addr; } return args_addr; } AppleGetPendingItemsHandler::GetPendingItemsReturnInfo AppleGetPendingItemsHandler::GetPendingItems (Thread &thread, addr_t queue, addr_t page_to_free, uint64_t page_to_free_size, Error &error) { lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); ProcessSP process_sp (thread.CalculateProcess()); TargetSP target_sp (thread.CalculateTarget()); ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME)); GetPendingItemsReturnInfo return_value; return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; return_value.items_buffer_size = 0; return_value.count = 0; error.Clear(); if (thread.SafeToCallFunctions() == false) { if (log) log->Printf ("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_pending_items_return_values // { // uint64_t pending_items_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ // uint64_t pending_items_buffer_size; /* the size of the items buffer from libBacktraceRecording */ // uint64_t count; /* the number of items included in the queues buffer */ // }; // // void __lldb_backtrace_recording_get_pending_items // (struct get_pending_items_return_values *return_buffer, // int debug, // uint64_t /* dispatch_queue_t */ queue // 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 queue_value; queue_value.SetValueType (Value::eValueTypeScalar); queue_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); Mutex::Locker locker(m_get_pending_items_retbuffer_mutex); if (m_get_pending_items_return_buffer_addr == LLDB_INVALID_ADDRESS) { addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error); if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { if (log) log->Printf ("Failed to allocate memory for return buffer for get current queues func call"); return return_value; } m_get_pending_items_return_buffer_addr = bufaddr; } ValueList argument_values; return_buffer_ptr_value.GetScalar() = m_get_pending_items_return_buffer_addr; argument_values.PushValue (return_buffer_ptr_value); debug_value.GetScalar() = 0; argument_values.PushValue (debug_value); queue_value.GetScalar() = queue; argument_values.PushValue (queue_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 = SetupGetPendingItemsFunction (thread, argument_values); StreamString errors; ExecutionContext exe_ctx; FunctionCaller *get_pending_items_caller = m_get_pending_items_impl_code->GetFunctionCaller(); EvaluateExpressionOptions options; options.SetUnwindOnError (true); options.SetIgnoreBreakpoints (true); options.SetStopOthers (true); options.SetTimeoutUsec(500000); options.SetTryAllThreads (false); thread.CalculateExecutionContext (exe_ctx); if (get_pending_items_caller == NULL) { error.SetErrorString ("Unable to compile function to call __introspection_dispatch_queue_get_pending_items"); return return_value; } ExpressionResults func_call_ret; Value results; func_call_ret = get_pending_items_caller->ExecuteFunction (exe_ctx, &args_addr, options, errors, results); if (func_call_ret != eExpressionCompleted || !error.Success()) { if (log) log->Printf ("Unable to call __introspection_dispatch_queue_get_pending_items(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString("")); error.SetErrorString ("Unable to call __introspection_dispatch_queue_get_pending_items() for list of queues"); return return_value; } return_value.items_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error); if (!error.Success() || return_value.items_buffer_ptr == LLDB_INVALID_ADDRESS) { return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; return return_value; } return_value.items_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 8, 8, 0, error); if (!error.Success()) { return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; return return_value; } return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_pending_items_return_buffer_addr + 16, 8, 0, error); if (!error.Success()) { return_value.items_buffer_ptr = LLDB_INVALID_ADDRESS; return return_value; } if (log) log->Printf ("AppleGetPendingItemsHandler called __introspection_dispatch_queue_get_pending_items (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.items_buffer_ptr, return_value.items_buffer_size, return_value.count); return return_value; }