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clang-p2996/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.cpp
Jason Molenda 5fe4d141e0 Refactor (with some rewriting) the DynamicLoaderMacOSX plugin into 
a base class and a derived class, with the derived class containing
the methods specific to reading dyld's all_image_infos, dyld's
method of specifying images that have been loaded or unloaded, the
place where we put a breakpoint in dyld to get notified about newly
loaded or unloaded images.

This is in preparation for a second derived class which will use
some alternate methods for getting this information; that will be
a separate commit in the next few days.

There's a couple of ivars that should probably be in the derived
DyanmicLoaderMacOSX class instead of the base DynamicLoaderDarwin
class (m_dyld_image_infos, m_dyld_image_infos_stop_id).  I don't
think I'll need to use these in the new derived class - I'll 
move them down to DynamicLoaderMacOSX if it works out that way;
it'll simplify locking if I can do that.

<rdar://problem/25251243> 

llvm-svn: 275733
2016-07-17 21:27:32 +00:00

1236 lines
49 KiB
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//===-- DynamicLoaderMacOSXDYLD.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/DataBuffer.h"
#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Section.h"
#include "lldb/Core/State.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Target/ObjCLanguageRuntime.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlanRunToAddress.h"
#include "lldb/Target/StackFrame.h"
#include "DynamicLoaderMacOSXDYLD.h"
#include "DynamicLoaderDarwin.h"
//#define ENABLE_DEBUG_PRINTF // COMMENT THIS LINE OUT PRIOR TO CHECKIN
#ifdef ENABLE_DEBUG_PRINTF
#include <stdio.h>
#define DEBUG_PRINTF(fmt, ...) printf(fmt, ## __VA_ARGS__)
#else
#define DEBUG_PRINTF(fmt, ...)
#endif
#ifndef __APPLE__
#include "Utility/UuidCompatibility.h"
#else
#include <uuid/uuid.h>
#endif
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 *
DynamicLoaderMacOSXDYLD::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 (create)
return new DynamicLoaderMacOSXDYLD (process);
return NULL;
}
//----------------------------------------------------------------------
// Constructor
//----------------------------------------------------------------------
DynamicLoaderMacOSXDYLD::DynamicLoaderMacOSXDYLD (Process* process) :
DynamicLoaderDarwin(process),
m_dyld_all_image_infos_addr(LLDB_INVALID_ADDRESS),
m_dyld_all_image_infos(),
m_dyld_all_image_infos_stop_id (UINT32_MAX),
m_break_id(LLDB_INVALID_BREAK_ID),
m_mutex(),
m_process_image_addr_is_all_images_infos (false)
{
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
DynamicLoaderMacOSXDYLD::~DynamicLoaderMacOSXDYLD()
{
if (LLDB_BREAK_ID_IS_VALID(m_break_id))
m_process->GetTarget().RemoveBreakpointByID (m_break_id);
}
bool
DynamicLoaderMacOSXDYLD::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)
{
// We know if a process has exec'ed if our "m_dyld_all_image_infos_addr"
// value differs from the Process' image info address. When a process
// execs itself it might cause a change if ASLR is enabled.
const addr_t shlib_addr = m_process->GetImageInfoAddress ();
if (m_process_image_addr_is_all_images_infos == true && shlib_addr != m_dyld_all_image_infos_addr)
{
// The image info address from the process is the 'dyld_all_image_infos'
// address and it has changed.
did_exec = true;
}
else if (m_process_image_addr_is_all_images_infos == false && shlib_addr == m_dyld.address)
{
// The image info address from the process is the mach_header
// address for dyld and it has changed.
did_exec = true;
}
else
{
// ASLR might be disabled and dyld could have ended up in the same
// location. We should try and detect 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
DynamicLoaderMacOSXDYLD::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_dyld_all_image_infos_addr = LLDB_INVALID_ADDRESS;
m_dyld_all_image_infos.Clear();
m_break_id = LLDB_INVALID_BREAK_ID;
}
//----------------------------------------------------------------------
// Check if we have found DYLD yet
//----------------------------------------------------------------------
bool
DynamicLoaderMacOSXDYLD::DidSetNotificationBreakpoint()
{
return LLDB_BREAK_ID_IS_VALID (m_break_id);
}
void
DynamicLoaderMacOSXDYLD::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
DynamicLoaderMacOSXDYLD::DoInitialImageFetch()
{
if (m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS)
{
// Check the image info addr as it might point to the
// mach header for dyld, or it might point to the
// dyld_all_image_infos struct
const addr_t shlib_addr = m_process->GetImageInfoAddress ();
if (shlib_addr != LLDB_INVALID_ADDRESS)
{
ByteOrder byte_order = m_process->GetTarget().GetArchitecture().GetByteOrder();
uint8_t buf[4];
DataExtractor data (buf, sizeof(buf), byte_order, 4);
Error error;
if (m_process->ReadMemory (shlib_addr, buf, 4, error) == 4)
{
lldb::offset_t offset = 0;
uint32_t magic = data.GetU32 (&offset);
switch (magic)
{
case llvm::MachO::MH_MAGIC:
case llvm::MachO::MH_MAGIC_64:
case llvm::MachO::MH_CIGAM:
case llvm::MachO::MH_CIGAM_64:
m_process_image_addr_is_all_images_infos = false;
ReadDYLDInfoFromMemoryAndSetNotificationCallback(shlib_addr);
return;
default:
break;
}
}
// Maybe it points to the all image infos?
m_dyld_all_image_infos_addr = shlib_addr;
m_process_image_addr_is_all_images_infos = true;
}
}
if (m_dyld_all_image_infos_addr != LLDB_INVALID_ADDRESS)
{
if (ReadAllImageInfosStructure ())
{
if (m_dyld_all_image_infos.dyldImageLoadAddress != LLDB_INVALID_ADDRESS)
ReadDYLDInfoFromMemoryAndSetNotificationCallback (m_dyld_all_image_infos.dyldImageLoadAddress);
else
ReadDYLDInfoFromMemoryAndSetNotificationCallback (m_dyld_all_image_infos_addr & 0xfffffffffff00000ull);
return;
}
}
// Check some default values
Module *executable = m_process->GetTarget().GetExecutableModulePointer();
if (executable)
{
const ArchSpec &exe_arch = executable->GetArchitecture();
if (exe_arch.GetAddressByteSize() == 8)
{
ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x7fff5fc00000ull);
}
else if (exe_arch.GetMachine() == llvm::Triple::arm || exe_arch.GetMachine() == llvm::Triple::thumb || exe_arch.GetMachine() == llvm::Triple::aarch64)
{
ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x2fe00000);
}
else
{
ReadDYLDInfoFromMemoryAndSetNotificationCallback(0x8fe00000);
}
}
return;
}
//----------------------------------------------------------------------
// Assume that dyld is in memory at ADDR and try to parse it's load
// commands
//----------------------------------------------------------------------
bool
DynamicLoaderMacOSXDYLD::ReadDYLDInfoFromMemoryAndSetNotificationCallback(lldb::addr_t addr)
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
DataExtractor data; // Load command data
if (ReadMachHeader (addr, &m_dyld.header, &data))
{
if (m_dyld.header.filetype == llvm::MachO::MH_DYLINKER)
{
m_dyld.address = addr;
ModuleSP dyld_module_sp;
if (ParseLoadCommands (data, m_dyld, &m_dyld.file_spec))
{
if (m_dyld.file_spec)
{
UpdateDYLDImageInfoFromNewImageInfo (m_dyld);
}
}
dyld_module_sp = GetDYLDModule();
Target &target = m_process->GetTarget();
if (m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS && dyld_module_sp.get())
{
static ConstString g_dyld_all_image_infos ("dyld_all_image_infos");
const Symbol *symbol = dyld_module_sp->FindFirstSymbolWithNameAndType (g_dyld_all_image_infos, eSymbolTypeData);
if (symbol)
m_dyld_all_image_infos_addr = symbol->GetLoadAddress(&target);
}
// Update all image infos
InitializeFromAllImageInfos ();
// If we didn't have an executable before, but now we do, then the
// dyld module shared pointer might be unique and we may need to add
// it again (since Target::SetExecutableModule() will clear the
// images). So append the dyld module back to the list if it is
/// unique!
if (dyld_module_sp)
{
target.GetImages().AppendIfNeeded (dyld_module_sp);
// At this point we should have read in dyld's module, and so we should set breakpoints in it:
ModuleList modules;
modules.Append(dyld_module_sp);
target.ModulesDidLoad(modules);
SetDYLDModule (dyld_module_sp);
}
return true;
}
}
return false;
}
bool
DynamicLoaderMacOSXDYLD::NeedToDoInitialImageFetch ()
{
return m_dyld_all_image_infos_addr == LLDB_INVALID_ADDRESS;
}
//----------------------------------------------------------------------
// 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
DynamicLoaderMacOSXDYLD::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_image_mode mode - 0 = adding, 1 = removing
// Arg2: uint32_t infoCount - Number of shared libraries added
// Arg3: dyld_image_info info[] - Array of structs of the form:
// const struct mach_header *imageLoadAddress
// const char *imageFilePath
// uintptr_t imageFileModDate (a time_t)
DynamicLoaderMacOSXDYLD* dyld_instance = (DynamicLoaderMacOSXDYLD*) baton;
// First step is to see if we've already initialized the all image infos. If we haven't then this function
// will do so and return true. In the course of initializing the all_image_infos it will read the complete
// current state, so we don't need to figure out what has changed from the data passed in to us.
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->InitializeFromAllImageInfos())
return dyld_instance->GetStopWhenImagesChange();
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 input_value;
CompilerType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
CompilerType clang_uint32_type = clang_ast_context->GetBuiltinTypeForEncodingAndBitSize(lldb::eEncodingUint, 32);
input_value.SetValueType (Value::eValueTypeScalar);
input_value.SetCompilerType (clang_uint32_type);
// input_value.SetContext (Value::eContextTypeClangType, clang_uint32_type);
argument_values.PushValue (input_value);
argument_values.PushValue (input_value);
input_value.SetCompilerType (clang_void_ptr_type);
// input_value.SetContext (Value::eContextTypeClangType, clang_void_ptr_type);
argument_values.PushValue (input_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))
{
// Got the number added, now go through the array of added elements, putting out the mach header
// address, and adding the image.
// Note, I'm not putting in logging here, since the AddModules & RemoveModules functions do
// all the logging internally.
lldb::addr_t image_infos_addr = argument_values.GetValueAtIndex(2)->GetScalar().ULongLong();
if (dyld_mode == 0)
{
// This is add:
dyld_instance->AddModulesUsingImageInfosAddress (image_infos_addr, image_infos_count);
}
else
{
// This is remove:
dyld_instance->RemoveModulesUsingImageInfosAddress (image_infos_addr, image_infos_count);
}
}
}
}
}
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();
}
bool
DynamicLoaderMacOSXDYLD::ReadAllImageInfosStructure ()
{
std::lock_guard<std::recursive_mutex> guard(m_mutex);
// the all image infos is already valid for this process stop ID
if (m_process->GetStopID() == m_dyld_all_image_infos_stop_id)
return true;
m_dyld_all_image_infos.Clear();
if (m_dyld_all_image_infos_addr != LLDB_INVALID_ADDRESS)
{
ByteOrder byte_order = m_process->GetTarget().GetArchitecture().GetByteOrder();
uint32_t addr_size = 4;
if (m_dyld_all_image_infos_addr > UINT32_MAX)
addr_size = 8;
uint8_t buf[256];
DataExtractor data (buf, sizeof(buf), byte_order, addr_size);
lldb::offset_t offset = 0;
const size_t count_v2 = sizeof (uint32_t) + // version
sizeof (uint32_t) + // infoArrayCount
addr_size + // infoArray
addr_size + // notification
addr_size + // processDetachedFromSharedRegion + libSystemInitialized + pad
addr_size; // dyldImageLoadAddress
const size_t count_v11 = count_v2 +
addr_size + // jitInfo
addr_size + // dyldVersion
addr_size + // errorMessage
addr_size + // terminationFlags
addr_size + // coreSymbolicationShmPage
addr_size + // systemOrderFlag
addr_size + // uuidArrayCount
addr_size + // uuidArray
addr_size + // dyldAllImageInfosAddress
addr_size + // initialImageCount
addr_size + // errorKind
addr_size + // errorClientOfDylibPath
addr_size + // errorTargetDylibPath
addr_size; // errorSymbol
const size_t count_v13 = count_v11 +
addr_size + // sharedCacheSlide
sizeof (uuid_t); // sharedCacheUUID
UNUSED_IF_ASSERT_DISABLED(count_v13);
assert (sizeof (buf) >= count_v13);
Error error;
if (m_process->ReadMemory (m_dyld_all_image_infos_addr, buf, 4, error) == 4)
{
m_dyld_all_image_infos.version = data.GetU32(&offset);
// If anything in the high byte is set, we probably got the byte
// order incorrect (the process might not have it set correctly
// yet due to attaching to a program without a specified file).
if (m_dyld_all_image_infos.version & 0xff000000)
{
// We have guessed the wrong byte order. Swap it and try
// reading the version again.
if (byte_order == eByteOrderLittle)
byte_order = eByteOrderBig;
else
byte_order = eByteOrderLittle;
data.SetByteOrder (byte_order);
offset = 0;
m_dyld_all_image_infos.version = data.GetU32(&offset);
}
}
else
{
return false;
}
const size_t count = (m_dyld_all_image_infos.version >= 11) ? count_v11 : count_v2;
const size_t bytes_read = m_process->ReadMemory (m_dyld_all_image_infos_addr, buf, count, error);
if (bytes_read == count)
{
offset = 0;
m_dyld_all_image_infos.version = data.GetU32(&offset);
m_dyld_all_image_infos.dylib_info_count = data.GetU32(&offset);
m_dyld_all_image_infos.dylib_info_addr = data.GetPointer(&offset);
m_dyld_all_image_infos.notification = data.GetPointer(&offset);
m_dyld_all_image_infos.processDetachedFromSharedRegion = data.GetU8(&offset);
m_dyld_all_image_infos.libSystemInitialized = data.GetU8(&offset);
// Adjust for padding.
offset += addr_size - 2;
m_dyld_all_image_infos.dyldImageLoadAddress = data.GetPointer(&offset);
if (m_dyld_all_image_infos.version >= 11)
{
offset += addr_size * 8;
uint64_t dyld_all_image_infos_addr = data.GetPointer(&offset);
// When we started, we were given the actual address of the all_image_infos
// struct (probably via TASK_DYLD_INFO) in memory - this address is stored in
// m_dyld_all_image_infos_addr and is the most accurate address we have.
// We read the dyld_all_image_infos struct from memory; it contains its own address.
// If the address in the struct does not match the actual address,
// the dyld we're looking at has been loaded at a different location (slid) from
// where it intended to load. The addresses in the dyld_all_image_infos struct
// are the original, non-slid addresses, and need to be adjusted. Most importantly
// the address of dyld and the notification address need to be adjusted.
if (dyld_all_image_infos_addr != m_dyld_all_image_infos_addr)
{
uint64_t image_infos_offset = dyld_all_image_infos_addr - m_dyld_all_image_infos.dyldImageLoadAddress;
uint64_t notification_offset = m_dyld_all_image_infos.notification - m_dyld_all_image_infos.dyldImageLoadAddress;
m_dyld_all_image_infos.dyldImageLoadAddress = m_dyld_all_image_infos_addr - image_infos_offset;
m_dyld_all_image_infos.notification = m_dyld_all_image_infos.dyldImageLoadAddress + notification_offset;
}
}
m_dyld_all_image_infos_stop_id = m_process->GetStopID();
return true;
}
}
return false;
}
bool
DynamicLoaderMacOSXDYLD::AddModulesUsingImageInfosAddress (lldb::addr_t image_infos_addr, uint32_t image_infos_count)
{
ImageInfo::collection image_infos;
Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
if (log)
log->Printf ("Adding %d modules.\n", image_infos_count);
std::lock_guard<std::recursive_mutex> guard(m_mutex);
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
if (m_process->GetStopID() == m_dyld_image_infos_stop_id)
return true;
StructuredData::ObjectSP image_infos_json_sp = m_process->GetLoadedDynamicLibrariesInfos (image_infos_addr, image_infos_count);
if (image_infos_json_sp.get()
&& image_infos_json_sp->GetAsDictionary()
&& image_infos_json_sp->GetAsDictionary()->HasKey("images")
&& image_infos_json_sp->GetAsDictionary()->GetValueForKey("images")->GetAsArray()
&& image_infos_json_sp->GetAsDictionary()->GetValueForKey("images")->GetAsArray()->GetSize() == image_infos_count)
{
bool return_value = false;
if (JSONImageInformationIntoImageInfo (image_infos_json_sp, image_infos))
{
AddExecutableModuleIfInImageInfos (image_infos);
return_value = AddModulesUsingImageInfos (image_infos);
}
m_dyld_image_infos_stop_id = m_process->GetStopID();
return return_value;
}
if (!ReadImageInfos (image_infos_addr, image_infos_count, image_infos))
return false;
UpdateImageInfosHeaderAndLoadCommands (image_infos, image_infos_count, false);
bool return_value = AddModulesUsingImageInfos (image_infos);
m_dyld_image_infos_stop_id = m_process->GetStopID();
return return_value;
}
bool
DynamicLoaderMacOSXDYLD::RemoveModulesUsingImageInfosAddress (lldb::addr_t image_infos_addr, uint32_t image_infos_count)
{
ImageInfo::collection image_infos;
Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
std::lock_guard<std::recursive_mutex> guard(m_mutex);
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
if (m_process->GetStopID() == m_dyld_image_infos_stop_id)
return true;
// First read in the image_infos for the removed modules, and their headers & load commands.
if (!ReadImageInfos (image_infos_addr, image_infos_count, image_infos))
{
if (log)
log->PutCString ("Failed reading image infos array.");
return false;
}
if (log)
log->Printf ("Removing %d modules.", image_infos_count);
ModuleList unloaded_module_list;
for (uint32_t idx = 0; idx < image_infos.size(); ++idx)
{
if (log)
{
log->Printf ("Removing module at address=0x%16.16" PRIx64 ".", image_infos[idx].address);
image_infos[idx].PutToLog (log);
}
// Remove this image_infos from the m_all_image_infos. We do the comparison by address
// rather than by file spec because we can have many modules with the same "file spec" in the
// case that they are modules loaded from memory.
//
// Also copy over the uuid from the old entry to the removed entry so we can
// use it to lookup the module in the module list.
ImageInfo::collection::iterator pos, end = m_dyld_image_infos.end();
for (pos = m_dyld_image_infos.begin(); pos != end; pos++)
{
if (image_infos[idx].address == (*pos).address)
{
image_infos[idx].uuid = (*pos).uuid;
// Add the module from this image_info to the "unloaded_module_list". We'll remove them all at
// one go later on.
ModuleSP unload_image_module_sp (FindTargetModuleForImageInfo (image_infos[idx], false, NULL));
if (unload_image_module_sp.get())
{
// When we unload, be sure to use the image info from the old list,
// since that has sections correctly filled in.
UnloadModuleSections (unload_image_module_sp.get(), *pos);
unloaded_module_list.AppendIfNeeded (unload_image_module_sp);
}
else
{
if (log)
{
log->Printf ("Could not find module for unloading info entry:");
image_infos[idx].PutToLog(log);
}
}
// Then remove it from the m_dyld_image_infos:
m_dyld_image_infos.erase(pos);
break;
}
}
if (pos == end)
{
if (log)
{
log->Printf ("Could not find image_info entry for unloading image:");
image_infos[idx].PutToLog(log);
}
}
}
if (unloaded_module_list.GetSize() > 0)
{
if (log)
{
log->PutCString("Unloaded:");
unloaded_module_list.LogUUIDAndPaths (log, "DynamicLoaderMacOSXDYLD::ModulesDidUnload");
}
m_process->GetTarget().GetImages().Remove (unloaded_module_list);
}
m_dyld_image_infos_stop_id = m_process->GetStopID();
return true;
}
bool
DynamicLoaderMacOSXDYLD::ReadImageInfos (lldb::addr_t image_infos_addr,
uint32_t image_infos_count,
ImageInfo::collection &image_infos)
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
const ByteOrder endian = GetByteOrderFromMagic (m_dyld.header.magic);
const uint32_t addr_size = m_dyld.GetAddressByteSize();
image_infos.resize(image_infos_count);
const size_t count = image_infos.size() * 3 * addr_size;
DataBufferHeap info_data(count, 0);
Error error;
const size_t bytes_read = m_process->ReadMemory (image_infos_addr,
info_data.GetBytes(),
info_data.GetByteSize(),
error);
if (bytes_read == count)
{
lldb::offset_t info_data_offset = 0;
DataExtractor info_data_ref(info_data.GetBytes(), info_data.GetByteSize(), endian, addr_size);
for (size_t i = 0; i < image_infos.size() && info_data_ref.ValidOffset(info_data_offset); i++)
{
image_infos[i].address = info_data_ref.GetPointer(&info_data_offset);
lldb::addr_t path_addr = info_data_ref.GetPointer(&info_data_offset);
image_infos[i].mod_date = info_data_ref.GetPointer(&info_data_offset);
char raw_path[PATH_MAX];
m_process->ReadCStringFromMemory (path_addr, raw_path, sizeof(raw_path), error);
// don't resolve the path
if (error.Success())
{
const bool resolve_path = false;
image_infos[i].file_spec.SetFile(raw_path, resolve_path);
}
}
return true;
}
else
{
return false;
}
}
//----------------------------------------------------------------------
// If we have found where the "_dyld_all_image_infos" lives in memory,
// read the current info from it, and then update all image load
// addresses (or lack thereof). Only do this if this is the first time
// we're reading the dyld infos. Return true if we actually read anything,
// and false otherwise.
//----------------------------------------------------------------------
bool
DynamicLoaderMacOSXDYLD::InitializeFromAllImageInfos ()
{
Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
std::lock_guard<std::recursive_mutex> guard(m_mutex);
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
if (m_process->GetStopID() == m_dyld_image_infos_stop_id
|| m_dyld_image_infos.size() != 0)
return false;
if (ReadAllImageInfosStructure ())
{
// Nothing to load or unload?
if (m_dyld_all_image_infos.dylib_info_count == 0)
return true;
if (m_dyld_all_image_infos.dylib_info_addr == 0)
{
// DYLD is updating the images now. So we should say we have no images, and then we'll
// figure it out when we hit the added breakpoint.
return false;
}
else
{
if (!AddModulesUsingImageInfosAddress (m_dyld_all_image_infos.dylib_info_addr,
m_dyld_all_image_infos.dylib_info_count))
{
DEBUG_PRINTF("%s", "unable to read all data for all_dylib_infos.");
m_dyld_image_infos.clear();
}
}
// Now we have one more bit of business. If there is a library left in the images for our target that
// doesn't have a load address, then it must be something that we were expecting to load (for instance we
// read a load command for it) but it didn't in fact load - probably because DYLD_*_PATH pointed
// to an equivalent version. We don't want it to stay in the target's module list or it will confuse
// us, so unload it here.
Target &target = m_process->GetTarget();
const ModuleList &target_modules = target.GetImages();
ModuleList not_loaded_modules;
std::lock_guard<std::recursive_mutex> guard(target_modules.GetMutex());
size_t num_modules = target_modules.GetSize();
for (size_t i = 0; i < num_modules; i++)
{
ModuleSP module_sp = target_modules.GetModuleAtIndexUnlocked (i);
if (!module_sp->IsLoadedInTarget (&target))
{
if (log)
{
StreamString s;
module_sp->GetDescription (&s);
log->Printf ("Unloading pre-run module: %s.", s.GetData ());
}
not_loaded_modules.Append (module_sp);
}
}
if (not_loaded_modules.GetSize() != 0)
{
target.GetImages().Remove(not_loaded_modules);
}
return true;
}
else
return false;
}
//----------------------------------------------------------------------
// Read a mach_header at ADDR into HEADER, and also fill in the load
// command data into LOAD_COMMAND_DATA if it is non-NULL.
//
// Returns true if we succeed, false if we fail for any reason.
//----------------------------------------------------------------------
bool
DynamicLoaderMacOSXDYLD::ReadMachHeader (lldb::addr_t addr, llvm::MachO::mach_header *header, DataExtractor *load_command_data)
{
DataBufferHeap header_bytes(sizeof(llvm::MachO::mach_header), 0);
Error error;
size_t bytes_read = m_process->ReadMemory (addr,
header_bytes.GetBytes(),
header_bytes.GetByteSize(),
error);
if (bytes_read == sizeof(llvm::MachO::mach_header))
{
lldb::offset_t offset = 0;
::memset (header, 0, sizeof(llvm::MachO::mach_header));
// Get the magic byte unswapped so we can figure out what we are dealing with
DataExtractor data(header_bytes.GetBytes(), header_bytes.GetByteSize(), endian::InlHostByteOrder(), 4);
header->magic = data.GetU32(&offset);
lldb::addr_t load_cmd_addr = addr;
data.SetByteOrder(DynamicLoaderMacOSXDYLD::GetByteOrderFromMagic(header->magic));
switch (header->magic)
{
case llvm::MachO::MH_MAGIC:
case llvm::MachO::MH_CIGAM:
data.SetAddressByteSize(4);
load_cmd_addr += sizeof(llvm::MachO::mach_header);
break;
case llvm::MachO::MH_MAGIC_64:
case llvm::MachO::MH_CIGAM_64:
data.SetAddressByteSize(8);
load_cmd_addr += sizeof(llvm::MachO::mach_header_64);
break;
default:
return false;
}
// Read the rest of dyld's mach header
if (data.GetU32(&offset, &header->cputype, (sizeof(llvm::MachO::mach_header)/sizeof(uint32_t)) - 1))
{
if (load_command_data == NULL)
return true; // We were able to read the mach_header and weren't asked to read the load command bytes
DataBufferSP load_cmd_data_sp(new DataBufferHeap(header->sizeofcmds, 0));
size_t load_cmd_bytes_read = m_process->ReadMemory (load_cmd_addr,
load_cmd_data_sp->GetBytes(),
load_cmd_data_sp->GetByteSize(),
error);
if (load_cmd_bytes_read == header->sizeofcmds)
{
// Set the load command data and also set the correct endian
// swap settings and the correct address size
load_command_data->SetData(load_cmd_data_sp, 0, header->sizeofcmds);
load_command_data->SetByteOrder(data.GetByteOrder());
load_command_data->SetAddressByteSize(data.GetAddressByteSize());
return true; // We successfully read the mach_header and the load command data
}
return false; // We weren't able to read the load command data
}
}
return false; // We failed the read the mach_header
}
//----------------------------------------------------------------------
// Parse the load commands for an image
//----------------------------------------------------------------------
uint32_t
DynamicLoaderMacOSXDYLD::ParseLoadCommands (const DataExtractor& data, ImageInfo& dylib_info, FileSpec *lc_id_dylinker)
{
lldb::offset_t offset = 0;
uint32_t cmd_idx;
Segment segment;
dylib_info.Clear (true);
for (cmd_idx = 0; cmd_idx < dylib_info.header.ncmds; cmd_idx++)
{
// Clear out any load command specific data from DYLIB_INFO since
// we are about to read it.
if (data.ValidOffsetForDataOfSize (offset, sizeof(llvm::MachO::load_command)))
{
llvm::MachO::load_command load_cmd;
lldb::offset_t load_cmd_offset = offset;
load_cmd.cmd = data.GetU32 (&offset);
load_cmd.cmdsize = data.GetU32 (&offset);
switch (load_cmd.cmd)
{
case llvm::MachO::LC_SEGMENT:
{
segment.name.SetTrimmedCStringWithLength ((const char *)data.GetData(&offset, 16), 16);
// We are putting 4 uint32_t values 4 uint64_t values so
// we have to use multiple 32 bit gets below.
segment.vmaddr = data.GetU32 (&offset);
segment.vmsize = data.GetU32 (&offset);
segment.fileoff = data.GetU32 (&offset);
segment.filesize = data.GetU32 (&offset);
// Extract maxprot, initprot, nsects and flags all at once
data.GetU32(&offset, &segment.maxprot, 4);
dylib_info.segments.push_back (segment);
}
break;
case llvm::MachO::LC_SEGMENT_64:
{
segment.name.SetTrimmedCStringWithLength ((const char *)data.GetData(&offset, 16), 16);
// Extract vmaddr, vmsize, fileoff, and filesize all at once
data.GetU64(&offset, &segment.vmaddr, 4);
// Extract maxprot, initprot, nsects and flags all at once
data.GetU32(&offset, &segment.maxprot, 4);
dylib_info.segments.push_back (segment);
}
break;
case llvm::MachO::LC_ID_DYLINKER:
if (lc_id_dylinker)
{
const lldb::offset_t name_offset = load_cmd_offset + data.GetU32 (&offset);
const char *path = data.PeekCStr (name_offset);
lc_id_dylinker->SetFile (path, true);
}
break;
case llvm::MachO::LC_UUID:
dylib_info.uuid.SetBytes(data.GetData (&offset, 16));
break;
default:
break;
}
// Set offset to be the beginning of the next load command.
offset = load_cmd_offset + load_cmd.cmdsize;
}
}
// All sections listed in the dyld image info structure will all
// either be fixed up already, or they will all be off by a single
// slide amount that is determined by finding the first segment
// that is at file offset zero which also has bytes (a file size
// that is greater than zero) in the object file.
// Determine the slide amount (if any)
const size_t num_sections = dylib_info.segments.size();
for (size_t i = 0; i < num_sections; ++i)
{
// Iterate through the object file sections to find the
// first section that starts of file offset zero and that
// has bytes in the file...
if ((dylib_info.segments[i].fileoff == 0 && dylib_info.segments[i].filesize > 0) || (dylib_info.segments[i].name == ConstString("__TEXT")))
{
dylib_info.slide = dylib_info.address - dylib_info.segments[i].vmaddr;
// We have found the slide amount, so we can exit
// this for loop.
break;
}
}
return cmd_idx;
}
//----------------------------------------------------------------------
// Read the mach_header and load commands for each image that the
// _dyld_all_image_infos structure points to and cache the results.
//----------------------------------------------------------------------
void
DynamicLoaderMacOSXDYLD::UpdateImageInfosHeaderAndLoadCommands(ImageInfo::collection &image_infos,
uint32_t infos_count,
bool update_executable)
{
uint32_t exe_idx = UINT32_MAX;
// Read any UUID values that we can get
for (uint32_t i = 0; i < infos_count; i++)
{
if (!image_infos[i].UUIDValid())
{
DataExtractor data; // Load command data
if (!ReadMachHeader (image_infos[i].address, &image_infos[i].header, &data))
continue;
ParseLoadCommands (data, image_infos[i], NULL);
if (image_infos[i].header.filetype == llvm::MachO::MH_EXECUTE)
exe_idx = i;
}
}
Target &target = m_process->GetTarget();
if (exe_idx < image_infos.size())
{
const bool can_create = true;
ModuleSP exe_module_sp (FindTargetModuleForImageInfo (image_infos[exe_idx], can_create, NULL));
if (exe_module_sp)
{
UpdateImageLoadAddress (exe_module_sp.get(), image_infos[exe_idx]);
if (exe_module_sp.get() != target.GetExecutableModulePointer())
{
// Don't load dependent images since we are in dyld where we will know
// and find out about all images that are loaded. Also when setting the
// executable module, it will clear the targets module list, and if we
// have an in memory dyld module, it will get removed from the list
// so we will need to add it back after setting the executable module,
// so we first try and see if we already have a weak pointer to the
// dyld module, make it into a shared pointer, then add the executable,
// then re-add it back to make sure it is always in the list.
ModuleSP dyld_module_sp(GetDYLDModule ());
const bool get_dependent_images = false;
m_process->GetTarget().SetExecutableModule (exe_module_sp,
get_dependent_images);
if (dyld_module_sp)
{
if(target.GetImages().AppendIfNeeded (dyld_module_sp))
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
// Also add it to the section list.
UpdateImageLoadAddress(dyld_module_sp.get(), m_dyld);
}
}
}
}
}
}
//----------------------------------------------------------------------
// Dump the _dyld_all_image_infos members and all current image infos
// that we have parsed to the file handle provided.
//----------------------------------------------------------------------
void
DynamicLoaderMacOSXDYLD::PutToLog(Log *log) const
{
if (log == NULL)
return;
std::lock_guard<std::recursive_mutex> guard(m_mutex);
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
log->Printf("dyld_all_image_infos = { version=%d, count=%d, addr=0x%8.8" PRIx64 ", notify=0x%8.8" PRIx64 " }",
m_dyld_all_image_infos.version,
m_dyld_all_image_infos.dylib_info_count,
(uint64_t)m_dyld_all_image_infos.dylib_info_addr,
(uint64_t)m_dyld_all_image_infos.notification);
size_t i;
const size_t count = m_dyld_image_infos.size();
if (count > 0)
{
log->PutCString("Loaded:");
for (i = 0; i<count; i++)
m_dyld_image_infos[i].PutToLog(log);
}
}
bool
DynamicLoaderMacOSXDYLD::SetNotificationBreakpoint ()
{
DEBUG_PRINTF("DynamicLoaderMacOSXDYLD::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState()));
if (m_break_id == LLDB_INVALID_BREAK_ID)
{
if (m_dyld_all_image_infos.notification != LLDB_INVALID_ADDRESS)
{
Address so_addr;
// Set the notification breakpoint and install a breakpoint
// callback function that will get called each time the
// breakpoint gets hit. We will use this to track when shared
// libraries get loaded/unloaded.
bool resolved = m_process->GetTarget().ResolveLoadAddress(m_dyld_all_image_infos.notification, so_addr);
if (!resolved)
{
ModuleSP dyld_module_sp = m_dyld_module_wp.lock();
if (dyld_module_sp)
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
UpdateImageLoadAddress (dyld_module_sp.get(), m_dyld);
resolved = m_process->GetTarget().ResolveLoadAddress(m_dyld_all_image_infos.notification, so_addr);
}
}
if (resolved)
{
Breakpoint *dyld_break = m_process->GetTarget().CreateBreakpoint (so_addr, true, false).get();
dyld_break->SetCallback (DynamicLoaderMacOSXDYLD::NotifyBreakpointHit, this, true);
dyld_break->SetBreakpointKind ("shared-library-event");
m_break_id = dyld_break->GetID();
}
}
}
return m_break_id != LLDB_INVALID_BREAK_ID;
}
Error
DynamicLoaderMacOSXDYLD::CanLoadImage ()
{
Error error;
// In order for us to tell if we can load a shared library we verify that
// the dylib_info_addr isn't zero (which means no shared libraries have
// been set yet, or dyld is currently mucking with the shared library list).
if (ReadAllImageInfosStructure ())
{
// TODO: also check the _dyld_global_lock_held variable in libSystem.B.dylib?
// TODO: check the malloc lock?
// TODO: check the objective C lock?
if (m_dyld_all_image_infos.dylib_info_addr != 0)
return error; // Success
}
error.SetErrorString("unsafe to load or unload shared libraries");
return error;
}
void
DynamicLoaderMacOSXDYLD::Initialize()
{
PluginManager::RegisterPlugin (GetPluginNameStatic(),
GetPluginDescriptionStatic(),
CreateInstance);
}
void
DynamicLoaderMacOSXDYLD::Terminate()
{
PluginManager::UnregisterPlugin (CreateInstance);
}
lldb_private::ConstString
DynamicLoaderMacOSXDYLD::GetPluginNameStatic()
{
static ConstString g_name("macosx-dyld");
return g_name;
}
const char *
DynamicLoaderMacOSXDYLD::GetPluginDescriptionStatic()
{
return "Dynamic loader plug-in that watches for shared library loads/unloads in MacOSX user processes.";
}
//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
lldb_private::ConstString
DynamicLoaderMacOSXDYLD::GetPluginName()
{
return GetPluginNameStatic();
}
uint32_t
DynamicLoaderMacOSXDYLD::GetPluginVersion()
{
return 1;
}
uint32_t
DynamicLoaderMacOSXDYLD::AddrByteSize()
{
std::lock_guard<std::recursive_mutex> baseclass_guard(GetMutex());
switch (m_dyld.header.magic)
{
case llvm::MachO::MH_MAGIC:
case llvm::MachO::MH_CIGAM:
return 4;
case llvm::MachO::MH_MAGIC_64:
case llvm::MachO::MH_CIGAM_64:
return 8;
default:
break;
}
return 0;
}
lldb::ByteOrder
DynamicLoaderMacOSXDYLD::GetByteOrderFromMagic(uint32_t magic)
{
switch (magic)
{
case llvm::MachO::MH_MAGIC:
case llvm::MachO::MH_MAGIC_64:
return endian::InlHostByteOrder();
case llvm::MachO::MH_CIGAM:
case llvm::MachO::MH_CIGAM_64:
if (endian::InlHostByteOrder() == lldb::eByteOrderBig)
return lldb::eByteOrderLittle;
else
return lldb::eByteOrderBig;
default:
break;
}
return lldb::eByteOrderInvalid;
}
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