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//===-- DynamicLoaderMacOS.cpp -----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Section.h"
#include "lldb/Core/State.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/StackFrame.h"
#include "DynamicLoaderMacOS.h"
#include "DynamicLoaderDarwin.h"
using namespace lldb;
using namespace lldb_private;
//----------------------------------------------------------------------
// Create an instance of this class. This function is filled into
// the plugin info class that gets handed out by the plugin factory and
// allows the lldb to instantiate an instance of this class.
//----------------------------------------------------------------------
DynamicLoader *
DynamicLoaderMacOS::CreateInstance (Process* process, bool force)
{
bool create = force;
if (!create)
{
create = true;
Module* exe_module = process->GetTarget().GetExecutableModulePointer();
if (exe_module)
{
ObjectFile *object_file = exe_module->GetObjectFile();
if (object_file)
{
create = (object_file->GetStrata() == ObjectFile::eStrataUser);
}
}
if (create)
{
const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple();
switch (triple_ref.getOS())
{
case llvm::Triple::Darwin:
case llvm::Triple::MacOSX:
case llvm::Triple::IOS:
case llvm::Triple::TvOS:
case llvm::Triple::WatchOS:
create = triple_ref.getVendor() == llvm::Triple::Apple;
break;
default:
create = false;
break;
}
}
}
if (UseDYLDSPI (process) == false)
{
create = false;
}
if (create)
return new DynamicLoaderMacOS (process);
return NULL;
}
//----------------------------------------------------------------------
// Constructor
//----------------------------------------------------------------------
DynamicLoaderMacOS::DynamicLoaderMacOS (Process* process) :
DynamicLoaderDarwin(process),
m_image_infos_stop_id (UINT32_MAX),
m_break_id(LLDB_INVALID_BREAK_ID),
m_mutex()
{
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
DynamicLoaderMacOS::~DynamicLoaderMacOS()
{
if (LLDB_BREAK_ID_IS_VALID(m_break_id))
m_process->GetTarget().RemoveBreakpointByID (m_break_id);
}
bool
DynamicLoaderMacOS::ProcessDidExec ()
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
bool did_exec = false;
if (m_process)
{
// If we are stopped after an exec, we will have only one thread...
if (m_process->GetThreadList().GetSize() == 1)
{
// See if we are stopped at '_dyld_start'
ThreadSP thread_sp (m_process->GetThreadList().GetThreadAtIndex(0));
if (thread_sp)
{
lldb::StackFrameSP frame_sp (thread_sp->GetStackFrameAtIndex(0));
if (frame_sp)
{
const Symbol *symbol = frame_sp->GetSymbolContext(eSymbolContextSymbol).symbol;
if (symbol)
{
if (symbol->GetName() == ConstString("_dyld_start"))
did_exec = true;
}
}
}
}
}
if (did_exec)
{
m_libpthread_module_wp.reset();
m_pthread_getspecific_addr.Clear();
}
return did_exec;
}
//----------------------------------------------------------------------
// Clear out the state of this class.
//----------------------------------------------------------------------
void
DynamicLoaderMacOS::DoClear ()
{
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (LLDB_BREAK_ID_IS_VALID(m_break_id))
m_process->GetTarget().RemoveBreakpointByID (m_break_id);
m_break_id = LLDB_INVALID_BREAK_ID;
}
//----------------------------------------------------------------------
// Check if we have found DYLD yet
//----------------------------------------------------------------------
bool
DynamicLoaderMacOS::DidSetNotificationBreakpoint()
{
return LLDB_BREAK_ID_IS_VALID (m_break_id);
}
void
DynamicLoaderMacOS::ClearNotificationBreakpoint ()
{
if (LLDB_BREAK_ID_IS_VALID (m_break_id))
{
m_process->GetTarget().RemoveBreakpointByID (m_break_id);
}
}
//----------------------------------------------------------------------
// Try and figure out where dyld is by first asking the Process
// if it knows (which currently calls down in the lldb::Process
// to get the DYLD info (available on SnowLeopard only). If that fails,
// then check in the default addresses.
//----------------------------------------------------------------------
void
DynamicLoaderMacOS::DoInitialImageFetch()
{
Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
StructuredData::ObjectSP all_image_info_json_sp (m_process->GetLoadedDynamicLibrariesInfos ());
ImageInfo::collection image_infos;
if (all_image_info_json_sp.get()
&& all_image_info_json_sp->GetAsDictionary()
&& all_image_info_json_sp->GetAsDictionary()->HasKey("images")
&& all_image_info_json_sp->GetAsDictionary()->GetValueForKey("images")->GetAsArray())
{
if (JSONImageInformationIntoImageInfo (all_image_info_json_sp, image_infos))
{
if (log)
log->Printf ("Initial module fetch: Adding %" PRId64 " modules.\n", (uint64_t) image_infos.size());
UpdateSpecialBinariesFromNewImageInfos (image_infos);
AddModulesUsingImageInfos (image_infos);
}
}
m_dyld_image_infos_stop_id = m_process->GetStopID();
}
bool
DynamicLoaderMacOS::NeedToDoInitialImageFetch ()
{
return true;
}
//----------------------------------------------------------------------
// Static callback function that gets called when our DYLD notification
// breakpoint gets hit. We update all of our image infos and then
// let our super class DynamicLoader class decide if we should stop
// or not (based on global preference).
//----------------------------------------------------------------------
bool
DynamicLoaderMacOS::NotifyBreakpointHit (void *baton,
StoppointCallbackContext *context,
lldb::user_id_t break_id,
lldb::user_id_t break_loc_id)
{
// Let the event know that the images have changed
// DYLD passes three arguments to the notification breakpoint.
// Arg1: enum dyld_notify_mode mode - 0 = adding, 1 = removing, 2 = remove all
// Arg2: unsigned long icount - Number of shared libraries added/removed
// Arg3: uint64_t mach_headers[] - Array of load addresses of binaries added/removed
DynamicLoaderMacOS* dyld_instance = (DynamicLoaderMacOS*) baton;
ExecutionContext exe_ctx (context->exe_ctx_ref);
Process *process = exe_ctx.GetProcessPtr();
// This is a sanity check just in case this dyld_instance is an old dyld plugin's breakpoint still lying around.
if (process != dyld_instance->m_process)
return false;
if (dyld_instance->m_image_infos_stop_id != UINT32_MAX
&& process->GetStopID() < dyld_instance->m_image_infos_stop_id)
{
return false;
}
const lldb::ABISP &abi = process->GetABI();
if (abi)
{
// Build up the value array to store the three arguments given above, then get the values from the ABI:
ClangASTContext *clang_ast_context = process->GetTarget().GetScratchClangASTContext();
ValueList argument_values;
Value mode_value; // enum dyld_notify_mode { dyld_notify_adding=0, dyld_notify_removing=1, dyld_notify_remove_all=2 };
Value count_value; // unsigned long count
Value headers_value; // uint64_t machHeaders[] (aka void*)
CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
CompilerType clang_uint32_type = clang_ast_context->GetBuiltinTypeForEncodingAndBitSize(lldb::eEncodingUint, 32);
CompilerType clang_uint64_type = clang_ast_context->GetBuiltinTypeForEncodingAndBitSize(lldb::eEncodingUint, 32);
mode_value.SetValueType (Value::eValueTypeScalar);
mode_value.SetCompilerType (clang_uint32_type);
if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 4)
{
count_value.SetValueType (Value::eValueTypeScalar);
count_value.SetCompilerType (clang_uint32_type);
}
else
{
count_value.SetValueType (Value::eValueTypeScalar);
count_value.SetCompilerType (clang_uint64_type);
}
headers_value.SetValueType (Value::eValueTypeScalar);
headers_value.SetCompilerType (clang_void_ptr_type);
argument_values.PushValue (mode_value);
argument_values.PushValue (count_value);
argument_values.PushValue (headers_value);
if (abi->GetArgumentValues (exe_ctx.GetThreadRef(), argument_values))
{
uint32_t dyld_mode = argument_values.GetValueAtIndex(0)->GetScalar().UInt (-1);
if (dyld_mode != static_cast<uint32_t>(-1))
{
// Okay the mode was right, now get the number of elements, and the array of new elements...
uint32_t image_infos_count = argument_values.GetValueAtIndex(1)->GetScalar().UInt (-1);
if (image_infos_count != static_cast<uint32_t>(-1))
{
addr_t header_array = argument_values.GetValueAtIndex(2)->GetScalar().ULongLong(-1);
if (header_array != static_cast<uint64_t>(-1))
{
std::vector<addr_t> image_load_addresses;
for (uint64_t i = 0; i < image_infos_count ; i++)
{
Error error;
addr_t addr = process->ReadUnsignedIntegerFromMemory (header_array + (8 * i), 8, LLDB_INVALID_ADDRESS, error);
if (addr != LLDB_INVALID_ADDRESS)
{
image_load_addresses.push_back (addr);
}
}
if (dyld_mode == 0)
{
// dyld_notify_adding
dyld_instance->AddBinaries (image_load_addresses);
}
else if (dyld_mode == 1)
{
// dyld_notify_removing
dyld_instance->UnloadImages (image_load_addresses);
}
else if (dyld_mode == 2)
{
// dyld_notify_remove_all
dyld_instance->UnloadAllImages ();
}
}
}
}
}
}
else
{
process->GetTarget().GetDebugger().GetAsyncErrorStream()->Printf("No ABI plugin located for triple %s -- shared libraries will not be registered!\n", process->GetTarget().GetArchitecture().GetTriple().getTriple().c_str());
}
// Return true to stop the target, false to just let the target run
return dyld_instance->GetStopWhenImagesChange();
}
void
DynamicLoaderMacOS::AddBinaries (const std::vector<lldb::addr_t> &load_addresses)
{
Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
ImageInfo::collection image_infos;
if (log)
log->Printf ("Adding %" PRId64 " modules.", (uint64_t) load_addresses.size());
StructuredData::ObjectSP binaries_info_sp = m_process->GetLoadedDynamicLibrariesInfos (load_addresses);
if (binaries_info_sp.get()
&& binaries_info_sp->GetAsDictionary()
&& binaries_info_sp->GetAsDictionary()->HasKey("images")
&& binaries_info_sp->GetAsDictionary()->GetValueForKey("images")->GetAsArray()
&& binaries_info_sp->GetAsDictionary()->GetValueForKey("images")->GetAsArray()->GetSize() == load_addresses.size())
{
if (JSONImageInformationIntoImageInfo (binaries_info_sp, image_infos))
{
UpdateSpecialBinariesFromNewImageInfos (image_infos);
AddModulesUsingImageInfos (image_infos);
}
m_dyld_image_infos_stop_id = m_process->GetStopID();
}
}
// Dump the _dyld_all_image_infos members and all current image infos
// that we have parsed to the file handle provided.
//----------------------------------------------------------------------
void
DynamicLoaderMacOS::PutToLog(Log *log) const
{
if (log == NULL)
return;
}
bool
DynamicLoaderMacOS::SetNotificationBreakpoint ()
{
if (m_break_id == LLDB_INVALID_BREAK_ID)
{
ConstString g_symbol_name ("_dyld_debugger_notification");
const Symbol *symbol = nullptr;
ModuleSP dyld_sp (GetDYLDModule());
if (dyld_sp)
{
symbol = dyld_sp->FindFirstSymbolWithNameAndType (g_symbol_name, eSymbolTypeCode);
}
if (symbol && (symbol->ValueIsAddress() || symbol->GetAddressRef().IsValid()))
{
addr_t symbol_address = symbol->GetAddressRef().GetOpcodeLoadAddress(&m_process->GetTarget());
if (symbol_address != LLDB_INVALID_ADDRESS)
{
bool internal = true;
bool hardware = false;
Breakpoint *breakpoint = m_process->GetTarget().CreateBreakpoint(symbol_address, internal, hardware).get();
breakpoint->SetCallback (DynamicLoaderMacOS::NotifyBreakpointHit, this, true);
breakpoint->SetBreakpointKind ("shared-library-event");
m_break_id = breakpoint->GetID();
}
}
}
return m_break_id != LLDB_INVALID_BREAK_ID;
}
addr_t
DynamicLoaderMacOS::GetDyldLockVariableAddressFromModule (Module *module)
{
SymbolContext sc;
SymbolVendor *sym_vendor = module->GetSymbolVendor ();
Target &target = m_process->GetTarget ();
if (sym_vendor)
{
Symtab *symtab = sym_vendor->GetSymtab();
if (symtab)
{
std::vector<uint32_t> match_indexes;
ConstString g_symbol_name ("_dyld_global_lock_held");
uint32_t num_matches = 0;
num_matches = symtab->AppendSymbolIndexesWithName (g_symbol_name, match_indexes);
if (num_matches == 1)
{
Symbol *symbol = symtab->SymbolAtIndex (match_indexes[0]);
if (symbol && (symbol->ValueIsAddress() || symbol->GetAddressRef().IsValid()))
{
return symbol->GetAddressRef().GetOpcodeLoadAddress(&target);
}
}
}
}
return LLDB_INVALID_ADDRESS;
}
// Look for this symbol:
//
// int __attribute__((visibility("hidden"))) _dyld_global_lock_held = 0;
//
// in libdyld.dylib.
Error
DynamicLoaderMacOS::CanLoadImage ()
{
Error error;
addr_t symbol_address = LLDB_INVALID_ADDRESS;
Target &target = m_process->GetTarget ();
const ModuleList &target_modules = target.GetImages();
std::lock_guard<std::recursive_mutex> guard(target_modules.GetMutex());
const size_t num_modules = target_modules.GetSize();
ConstString g_libdyld_name ("libdyld.dylib");
// Find any modules named "libdyld.dylib" and look for the symbol there first
for (size_t i = 0; i < num_modules; i++)
{
Module *module_pointer = target_modules.GetModulePointerAtIndexUnlocked (i);
if (module_pointer)
{
if (module_pointer->GetFileSpec().GetFilename() == g_libdyld_name)
{
symbol_address = GetDyldLockVariableAddressFromModule (module_pointer);
if (symbol_address != LLDB_INVALID_ADDRESS)
break;
}
}
}
// Search through all modules looking for the symbol in them
if (symbol_address == LLDB_INVALID_ADDRESS)
{
for (size_t i = 0; i < num_modules; i++)
{
Module *module_pointer = target_modules.GetModulePointerAtIndexUnlocked (i);
if (module_pointer)
{
addr_t symbol_address = GetDyldLockVariableAddressFromModule (module_pointer);
if (symbol_address != LLDB_INVALID_ADDRESS)
break;
}
}
}
// Default assumption is that it is OK to load images.
// Only say that we cannot load images if we find the symbol in libdyld and it indicates that
// we cannot.
if (symbol_address != LLDB_INVALID_ADDRESS)
{
{
int lock_held = m_process->ReadUnsignedIntegerFromMemory (symbol_address, 4, 0, error);
if (lock_held != 0)
{
error.SetErrorToGenericError();
}
}
}
else
{
// If we were unable to find _dyld_global_lock_held in any modules, or it is not loaded into
// memory yet, we may be at process startup (sitting at _dyld_start) - so we should not allow
// dlopen calls.
error.SetErrorToGenericError();
}
return error;
}
void
DynamicLoaderMacOS::Initialize()
{
PluginManager::RegisterPlugin (GetPluginNameStatic(),
GetPluginDescriptionStatic(),
CreateInstance);
}
void
DynamicLoaderMacOS::Terminate()
{
PluginManager::UnregisterPlugin (CreateInstance);
}
lldb_private::ConstString
DynamicLoaderMacOS::GetPluginNameStatic()
{
static ConstString g_name("macos-dyld");
return g_name;
}
const char *
DynamicLoaderMacOS::GetPluginDescriptionStatic()
{
return "Dynamic loader plug-in that watches for shared library loads/unloads in MacOSX user processes.";
}
//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
lldb_private::ConstString
DynamicLoaderMacOS::GetPluginName()
{
return GetPluginNameStatic();
}
uint32_t
DynamicLoaderMacOS::GetPluginVersion()
{
return 1;
}