Bug ID 22312
Summary The value of linkedit_load_addr is invalid in ObjectFileMachO::ParseSymtab
Product lldb
Version unspecified
Hardware PC
OS All
Status NEW
Severity normal
Priority P
Component All Bugs
Assignee lldb-dev@cs.uiuc.edu
Reporter cosmo.shih@gmail.com
Classification Unclassified
The value of linkedit_load_addr is invalid due to section list of target is
empty in ObjectFileMachO::ParseSymtab.
There're two related problems:
1. linkedit_load_addr must be invalid, because Target::ClearsModules empty the
section list of target
2. DynamicLoaderMacOSXDYLD::UpdateImageLoadAddress happened before
Target::SetExecutableModule.
The first problem won't fix even if we fix the second problem by moving
UpdateImageLoadAddress below.
Maybe these code need some refactory.
look these:
#0 ObjectFileMachO::ParseSymtab() at
source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:1744
#1 ObjectFileMachO::GetSymtab() at
source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:1039
#2 SymbolFileSymtab::CalculateAbilities() at
source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp:96
#3 lldb_private::SymbolFile::GetAbilities() at
include/lldb/Symbol/SymbolFile.h:96
#4 lldb_private::SymbolFile::FindPlugin(lldb_private::ObjectFile*) at
source/Symbol/SymbolFile.cpp:55
#5
lldb_private::SymbolVendor::AddSymbolFileRepresentation(std::__1::shared_ptr<lldb_private::ObjectFile>
const&) at source/Symbol/SymbolVendor.cpp:92
#6 SymbolVendorMacOSX::CreateInstance(...) at
source/Plugins/SymbolVendor/MacOSX/SymbolVendorMacOSX.cpp:291
#7 lldb_private::SymbolVendor::FindPlugin(...) at
source/Symbol/SymbolVendor.cpp:42
#8 lldb_private::Module::GetSymbolVendor(bool, lldb_private::Stream*) at
source/Core/Module.cpp:958
#9 PlatformDarwin::LocateExecutableScriptingResources(...) at
source/Plugins/Platform/MacOSX/PlatformDarwin.cpp:72
#10 lldb_private::Module::LoadScriptingResourceInTarget(...) at
source/Core/Module.cpp:1441
#11 LoadScriptingResourceForModule(...) at source/Target/Target.cpp:1006
#12 lldb_private::Target::ModuleAdded(...) at source/Target/Target.cpp:1146
#13 non-virtual thunk to lldb_private::Target::ModuleAdded(...) at
source/Target/Target.cpp:1148
#14 lldb_private::ModuleList::AppendImpl(...) at
source/Core/ModuleList.cpp:87
#15 lldb_private::ModuleList::Append(...) at source/Core/ModuleList.cpp:94
#16 lldb_private::Target::SetExecutableModule(...) at
source/Target/Target.cpp:1049
#17 DynamicLoaderMacOSXDYLD::UpdateImageInfosHeaderAndLoadCommands(...) at
source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.cpp:1349
#18 DynamicLoaderMacOSXDYLD::AddModulesUsingImageInfosAddress(...) at
source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.cpp:805
void Target::SetExecutableModule (ModuleSP& executable_sp, bool
get_dependent_files)
{
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_TARGET));
ClearModules(false);
if (executable_sp.get())
{
Timer scoped_timer (
__PRETTY_FUNCTION__,
"Target::SetExecutableModule (executable = '%s')",
executable_sp->GetFileSpec().GetPath().c_str()
);
// The first image is our exectuable file
// If we haven't set an architecture yet, reset our architecture based
on what we found in the executable module.
m_images.Append(executable_sp);
...
}
}
size_t ObjectFileMachO::ParseSymtab ()
{
...
SectionSP
linkedit_section_sp(section_list->FindSectionByName(GetSegmentNameLINKEDIT()));
// Reading mach file from memory in a process or core file...
if (linkedit_section_sp)
{
const addr_t linkedit_load_addr =
linkedit_section_sp->GetLoadBaseAddress(&target);
....
PlatformSP platform_sp (target.GetPlatform());
if (platform_sp && platform_sp->IsHost() && use_lldb_cache)
{
data_was_read = true;
nlist_data.SetData((void *)symoff_addr, nlist_data_byte_size,
eByteOrderLittle);
strtab_data.SetData((void *)strtab_addr, strtab_data_byte_size,
eByteOrderLittle);
if (function_starts_load_command.cmd)
{
const addr_t func_start_addr = linkedit_load_addr +
function_starts_load_command.dataoff - linkedit_file_offset;
function_starts_data.SetData ((void *)func_start_addr,
function_starts_load_command.datasize, eByteOrderLittle);
}
}
...
}
void
DynamicLoaderMacOSXDYLD::UpdateImageInfosHeaderAndLoadCommands(DYLDImageInfo::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 (FindTargetModuleForDYLDImageInfo
(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(m_dyld_module_wp.lock());
const bool get_dependent_images = false;
m_process->GetTarget().SetExecutableModule (exe_module_sp,
get_dependent_images);
if (dyld_module_sp)
target.GetImages().AppendIfNeeded (dyld_module_sp);
}
}
}
}