diff options
Diffstat (limited to 'contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/Hexagon-DYLD/DynamicLoaderHexagonDYLD.cpp')
| -rw-r--r-- | contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/Hexagon-DYLD/DynamicLoaderHexagonDYLD.cpp | 727 |
1 files changed, 727 insertions, 0 deletions
diff --git a/contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/Hexagon-DYLD/DynamicLoaderHexagonDYLD.cpp b/contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/Hexagon-DYLD/DynamicLoaderHexagonDYLD.cpp new file mode 100644 index 0000000..c79d96a --- /dev/null +++ b/contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/Hexagon-DYLD/DynamicLoaderHexagonDYLD.cpp @@ -0,0 +1,727 @@ +//===-- DynamicLoaderHexagon.h ----------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// C Includes +// C++ Includes +// Other libraries and framework includes +#include "lldb/Core/PluginManager.h" +#include "lldb/Core/Log.h" +#include "lldb/Core/Module.h" +#include "lldb/Core/ModuleSpec.h" +#include "lldb/Core/Section.h" +#include "lldb/Symbol/ObjectFile.h" +#include "lldb/Target/Process.h" +#include "lldb/Target/Target.h" +#include "lldb/Target/Thread.h" +#include "lldb/Target/ThreadPlanRunToAddress.h" +#include "lldb/Breakpoint/BreakpointLocation.h" + +#include "DynamicLoaderHexagonDYLD.h" + +using namespace lldb; +using namespace lldb_private; + +// Aidan 21/05/2014 +// +// Notes about hexagon dynamic loading: +// +// When we connect to a target we find the dyld breakpoint address. We put a +// breakpoint there with a callback 'RendezvousBreakpointHit()'. +// +// It is possible to find the dyld structure address from the ELF symbol table, +// but in the case of the simulator it has not been initialized before the +// target calls dlinit(). +// +// We can only safely parse the dyld structure after we hit the dyld breakpoint +// since at that time we know dlinit() must have been called. +// + +// Find the load address of a symbol +static lldb::addr_t findSymbolAddress( Process *proc, ConstString findName ) +{ + assert( proc != nullptr ); + + ModuleSP module = proc->GetTarget().GetExecutableModule(); + assert( module.get() != nullptr ); + + ObjectFile *exe = module->GetObjectFile(); + assert( exe != nullptr ); + + lldb_private::Symtab *symtab = exe->GetSymtab( ); + assert( symtab != nullptr ); + + for ( size_t i = 0; i < symtab->GetNumSymbols( ); i++ ) + { + const Symbol* sym = symtab->SymbolAtIndex( i ); + assert( sym != nullptr ); + const ConstString &symName = sym->GetName( ); + + if ( ConstString::Compare( findName, symName ) == 0 ) + { + Address addr = sym->GetAddress( ); + return addr.GetLoadAddress( & proc->GetTarget() ); + } + } + return LLDB_INVALID_ADDRESS; +} + +void +DynamicLoaderHexagonDYLD::Initialize() +{ + PluginManager::RegisterPlugin(GetPluginNameStatic(), + GetPluginDescriptionStatic(), + CreateInstance); +} + +void +DynamicLoaderHexagonDYLD::Terminate() +{ +} + +lldb_private::ConstString +DynamicLoaderHexagonDYLD::GetPluginName() +{ + return GetPluginNameStatic(); +} + +lldb_private::ConstString +DynamicLoaderHexagonDYLD::GetPluginNameStatic() +{ + static ConstString g_name("hexagon-dyld"); + return g_name; +} + +const char * +DynamicLoaderHexagonDYLD::GetPluginDescriptionStatic() +{ + return "Dynamic loader plug-in that watches for shared library " + "loads/unloads in Hexagon processes."; +} + +void +DynamicLoaderHexagonDYLD::GetPluginCommandHelp(const char *command, Stream *strm) +{ +} + +uint32_t +DynamicLoaderHexagonDYLD::GetPluginVersion() +{ + return 1; +} + +DynamicLoader * +DynamicLoaderHexagonDYLD::CreateInstance(Process *process, bool force) +{ + bool create = force; + if (!create) + { + const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple(); + if (triple_ref.getArch() == llvm::Triple::hexagon) + create = true; + } + + if (create) + return new DynamicLoaderHexagonDYLD(process); + return NULL; +} + +DynamicLoaderHexagonDYLD::DynamicLoaderHexagonDYLD(Process *process) + : DynamicLoader(process) + , m_rendezvous (process) + , m_load_offset(LLDB_INVALID_ADDRESS) + , m_entry_point(LLDB_INVALID_ADDRESS) + , m_dyld_bid (LLDB_INVALID_BREAK_ID) +{ +} + +DynamicLoaderHexagonDYLD::~DynamicLoaderHexagonDYLD() +{ + if (m_dyld_bid != LLDB_INVALID_BREAK_ID) + { + m_process->GetTarget().RemoveBreakpointByID (m_dyld_bid); + m_dyld_bid = LLDB_INVALID_BREAK_ID; + } +} + +void +DynamicLoaderHexagonDYLD::DidAttach() +{ + ModuleSP executable; + addr_t load_offset; + + executable = GetTargetExecutable(); + + // Find the difference between the desired load address in the elf file + // and the real load address in memory + load_offset = ComputeLoadOffset(); + + // Check that there is a valid executable + if ( executable.get( ) == nullptr ) + return; + + // Disable JIT for hexagon targets because its not supported + m_process->SetCanJIT(false); + + // Add the current executable to the module list + ModuleList module_list; + module_list.Append(executable); + + // Map the loaded sections of this executable + if ( load_offset != LLDB_INVALID_ADDRESS ) + UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_offset); + + // AD: confirm this? + // Load into LLDB all of the currently loaded executables in the stub + LoadAllCurrentModules(); + + // AD: confirm this? + // Callback for the target to give it the loaded module list + m_process->GetTarget().ModulesDidLoad(module_list); + + // Try to set a breakpoint at the rendezvous breakpoint. + // DidLaunch uses ProbeEntry() instead. That sets a breakpoint, + // at the dyld breakpoint address, with a callback so that when hit, + // the dyld structure can be parsed. + if (! SetRendezvousBreakpoint() ) + { + // fail + } +} + +void +DynamicLoaderHexagonDYLD::DidLaunch() +{ +} + +/// Checks to see if the target module has changed, updates the target +/// accordingly and returns the target executable module. +ModuleSP +DynamicLoaderHexagonDYLD::GetTargetExecutable() +{ + Target &target = m_process->GetTarget(); + ModuleSP executable = target.GetExecutableModule(); + + // There is no executable + if (! executable.get()) + return executable; + + // The target executable file does not exits + if (! executable->GetFileSpec().Exists()) + return executable; + + // Prep module for loading + ModuleSpec module_spec(executable->GetFileSpec(), executable->GetArchitecture()); + ModuleSP module_sp (new Module (module_spec)); + + // Check if the executable has changed and set it to the target executable if they differ. + if (module_sp.get() && module_sp->GetUUID().IsValid() && executable->GetUUID().IsValid()) + { + // if the executable has changed ?? + if (module_sp->GetUUID() != executable->GetUUID()) + executable.reset(); + } + else if (executable->FileHasChanged()) + executable.reset(); + + if ( executable.get( ) ) + return executable; + + // TODO: What case is this code used? + executable = target.GetSharedModule(module_spec); + if (executable.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 + const bool get_dependent_images = false; + target.SetExecutableModule(executable, get_dependent_images); + } + + return executable; +} + +Error +DynamicLoaderHexagonDYLD::ExecutePluginCommand(Args &command, Stream *strm) +{ + return Error(); +} + +Log * +DynamicLoaderHexagonDYLD::EnablePluginLogging(Stream *strm, Args &command) +{ + return NULL; +} + +//AD: Needs to be updated? +Error +DynamicLoaderHexagonDYLD::CanLoadImage() +{ + return Error(); +} + +void +DynamicLoaderHexagonDYLD::UpdateLoadedSections(ModuleSP module, addr_t link_map_addr, addr_t base_addr) +{ + Target &target = m_process->GetTarget(); + const SectionList *sections = GetSectionListFromModule(module); + + assert(sections && "SectionList missing from loaded module."); + + m_loaded_modules[module] = link_map_addr; + + const size_t num_sections = sections->GetSize(); + + for (unsigned i = 0; i < num_sections; ++i) + { + SectionSP section_sp (sections->GetSectionAtIndex(i)); + lldb::addr_t new_load_addr = section_sp->GetFileAddress() + base_addr; + + // AD: 02/05/14 + // since our memory map starts from address 0, we must not ignore + // sections that load to address 0. This violates the reference + // ELF spec, however is used for Hexagon. + + // If the file address of the section is zero then this is not an + // allocatable/loadable section (property of ELF sh_addr). Skip it. +// if (new_load_addr == base_addr) +// continue; + + target.SetSectionLoadAddress(section_sp, new_load_addr); + } +} + +/// Removes the loaded sections from the target in @p module. +/// +/// @param module The module to traverse. +void +DynamicLoaderHexagonDYLD::UnloadSections(const ModuleSP module) +{ + Target &target = m_process->GetTarget(); + const SectionList *sections = GetSectionListFromModule(module); + + assert(sections && "SectionList missing from unloaded module."); + + m_loaded_modules.erase(module); + + const size_t num_sections = sections->GetSize(); + for (size_t i = 0; i < num_sections; ++i) + { + SectionSP section_sp (sections->GetSectionAtIndex(i)); + target.SetSectionUnloaded(section_sp); + } +} + +// Place a breakpoint on <_rtld_debug_state> +bool +DynamicLoaderHexagonDYLD::SetRendezvousBreakpoint() +{ + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + + // This is the original code, which want to look in the rendezvous structure + // to find the breakpoint address. Its backwards for us, since we can easily + // find the breakpoint address, since it is exported in our executable. + // We however know that we cant read the Rendezvous structure until we have hit + // the breakpoint once. + const ConstString dyldBpName( "_rtld_debug_state" ); + addr_t break_addr = findSymbolAddress( m_process, dyldBpName ); + + Target &target = m_process->GetTarget(); + + // Do not try to set the breakpoint if we don't know where to put it + if ( break_addr == LLDB_INVALID_ADDRESS ) + { + if ( log ) + log->Printf( "Unable to locate _rtld_debug_state breakpoint address" ); + + return false; + } + + // Save the address of the rendezvous structure + m_rendezvous.SetBreakAddress( break_addr ); + + // If we haven't set the breakpoint before then set it + if (m_dyld_bid == LLDB_INVALID_BREAK_ID) + { + Breakpoint *dyld_break = target.CreateBreakpoint (break_addr, true, false).get(); + dyld_break->SetCallback(RendezvousBreakpointHit, this, true); + dyld_break->SetBreakpointKind ("shared-library-event"); + m_dyld_bid = dyld_break->GetID(); + + // Make sure our breakpoint is at the right address. + assert + ( + target.GetBreakpointByID(m_dyld_bid)-> + FindLocationByAddress(break_addr)-> + GetBreakpoint().GetID() + == m_dyld_bid + ); + + if ( log && dyld_break == nullptr ) + log->Printf( "Failed to create _rtld_debug_state breakpoint" ); + + // check we have successfully set bp + return (dyld_break != nullptr); + } + else + // rendezvous already set + return true; +} + +// We have just hit our breakpoint at <_rtld_debug_state> +bool +DynamicLoaderHexagonDYLD::RendezvousBreakpointHit(void *baton, + StoppointCallbackContext *context, + user_id_t break_id, + user_id_t break_loc_id) +{ + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + + if ( log ) + log->Printf( "Rendezvous breakpoint hit!" ); + + DynamicLoaderHexagonDYLD* dyld_instance = nullptr; + dyld_instance = static_cast<DynamicLoaderHexagonDYLD*>(baton); + + // if the dyld_instance is still not valid then + // try to locate it on the symbol table + if ( !dyld_instance->m_rendezvous.IsValid( ) ) + { + Process *proc = dyld_instance->m_process; + + const ConstString dyldStructName( "_rtld_debug" ); + addr_t structAddr = findSymbolAddress( proc, dyldStructName ); + + if ( structAddr != LLDB_INVALID_ADDRESS ) + { + dyld_instance->m_rendezvous.SetRendezvousAddress( structAddr ); + + if ( log ) + log->Printf( "Found _rtld_debug structure @ 0x%08lx", structAddr ); + } + else + { + if ( log ) + log->Printf( "Unable to resolve the _rtld_debug structure" ); + } + } + + dyld_instance->RefreshModules(); + + // Return true to stop the target, false to just let the target run. + return dyld_instance->GetStopWhenImagesChange(); +} + +/// Helper method for RendezvousBreakpointHit. Updates LLDB's current set +/// of loaded modules. +void +DynamicLoaderHexagonDYLD::RefreshModules() +{ + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + + if (!m_rendezvous.Resolve()) + return; + + HexagonDYLDRendezvous::iterator I; + HexagonDYLDRendezvous::iterator E; + + ModuleList &loaded_modules = m_process->GetTarget().GetImages(); + + if (m_rendezvous.ModulesDidLoad()) + { + ModuleList new_modules; + + E = m_rendezvous.loaded_end(); + for (I = m_rendezvous.loaded_begin(); I != E; ++I) + { + FileSpec file(I->path.c_str(), true); + ModuleSP module_sp = LoadModuleAtAddress(file, I->link_addr, I->base_addr); + if (module_sp.get()) + { + loaded_modules.AppendIfNeeded( module_sp ); + new_modules.Append(module_sp); + } + + if (log) + { + log->Printf( "Target is loading '%s'", I->path.c_str() ); + if (! module_sp.get() ) + log->Printf( "LLDB failed to load '%s'", I->path.c_str() ); + else + log->Printf( "LLDB successfully loaded '%s'", I->path.c_str() ); + } + + } + m_process->GetTarget().ModulesDidLoad(new_modules); + } + + if (m_rendezvous.ModulesDidUnload()) + { + ModuleList old_modules; + + E = m_rendezvous.unloaded_end(); + for (I = m_rendezvous.unloaded_begin(); I != E; ++I) + { + FileSpec file(I->path.c_str(), true); + ModuleSpec module_spec(file); + ModuleSP module_sp = loaded_modules.FindFirstModule (module_spec); + + if (module_sp.get()) + { + old_modules.Append(module_sp); + UnloadSections(module_sp); + } + + if (log) + log->Printf( "Target is unloading '%s'", I->path.c_str() ); + + } + loaded_modules.Remove(old_modules); + m_process->GetTarget().ModulesDidUnload(old_modules, false); + } +} + +//AD: This is very different to the Static Loader code. +// It may be wise to look over this and its relation to stack +// unwinding. +ThreadPlanSP +DynamicLoaderHexagonDYLD::GetStepThroughTrampolinePlan(Thread &thread, bool stop) +{ + ThreadPlanSP thread_plan_sp; + + StackFrame *frame = thread.GetStackFrameAtIndex(0).get(); + const SymbolContext &context = frame->GetSymbolContext(eSymbolContextSymbol); + Symbol *sym = context.symbol; + + if (sym == NULL || !sym->IsTrampoline()) + return thread_plan_sp; + + const ConstString &sym_name = sym->GetMangled().GetName(Mangled::ePreferMangled); + if (!sym_name) + return thread_plan_sp; + + SymbolContextList target_symbols; + Target &target = thread.GetProcess()->GetTarget(); + const ModuleList &images = target.GetImages(); + + images.FindSymbolsWithNameAndType(sym_name, eSymbolTypeCode, target_symbols); + size_t num_targets = target_symbols.GetSize(); + if (!num_targets) + return thread_plan_sp; + + typedef std::vector<lldb::addr_t> AddressVector; + AddressVector addrs; + for (size_t i = 0; i < num_targets; ++i) + { + SymbolContext context; + AddressRange range; + if (target_symbols.GetContextAtIndex(i, context)) + { + context.GetAddressRange(eSymbolContextEverything, 0, false, range); + lldb::addr_t addr = range.GetBaseAddress().GetLoadAddress(&target); + if (addr != LLDB_INVALID_ADDRESS) + addrs.push_back(addr); + } + } + + if (addrs.size() > 0) + { + AddressVector::iterator start = addrs.begin(); + AddressVector::iterator end = addrs.end(); + + std::sort(start, end); + addrs.erase(std::unique(start, end), end); + thread_plan_sp.reset(new ThreadPlanRunToAddress(thread, addrs, stop)); + } + + return thread_plan_sp; +} + +/// Helper for the entry breakpoint callback. Resolves the load addresses +/// of all dependent modules. +void +DynamicLoaderHexagonDYLD::LoadAllCurrentModules() +{ + HexagonDYLDRendezvous::iterator I; + HexagonDYLDRendezvous::iterator E; + ModuleList module_list; + + if (!m_rendezvous.Resolve()) + { + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + if (log) + log->Printf("DynamicLoaderHexagonDYLD::%s unable to resolve rendezvous address", __FUNCTION__); + return; + } + + // The rendezvous class doesn't enumerate the main module, so track + // that ourselves here. + ModuleSP executable = GetTargetExecutable(); + m_loaded_modules[executable] = m_rendezvous.GetLinkMapAddress(); + + + for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I) + { + const char *module_path = I->path.c_str(); + FileSpec file(module_path, false); + ModuleSP module_sp = LoadModuleAtAddress(file, I->link_addr, I->base_addr); + if (module_sp.get()) + { + module_list.Append(module_sp); + } + else + { + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + if (log) + log->Printf("DynamicLoaderHexagonDYLD::%s failed loading module %s at 0x%" PRIx64, + __FUNCTION__, module_path, I->base_addr); + } + } + + m_process->GetTarget().ModulesDidLoad(module_list); +} + +/// Helper for the entry breakpoint callback. Resolves the load addresses +/// of all dependent modules. +ModuleSP +DynamicLoaderHexagonDYLD::LoadModuleAtAddress(const FileSpec &file, addr_t link_map_addr, addr_t base_addr) +{ + Target &target = m_process->GetTarget(); + ModuleList &modules = target.GetImages(); + ModuleSP module_sp; + + ModuleSpec module_spec (file, target.GetArchitecture()); + + // check if module is currently loaded + if ((module_sp = modules.FindFirstModule (module_spec))) + { + UpdateLoadedSections(module_sp, link_map_addr, base_addr); + } + // try to load this module from disk + else if ((module_sp = target.GetSharedModule(module_spec))) + { + UpdateLoadedSections(module_sp, link_map_addr, base_addr); + } + + return module_sp; +} + +/// Computes a value for m_load_offset returning the computed address on +/// success and LLDB_INVALID_ADDRESS on failure. +addr_t +DynamicLoaderHexagonDYLD::ComputeLoadOffset() +{ + // Here we could send a GDB packet to know the load offset + // + // send: $qOffsets#4b + // get: Text=0;Data=0;Bss=0 + // + // Currently qOffsets is not supported by pluginProcessGDBRemote + // + return 0; +} + +// Here we must try to read the entry point directly from +// the elf header. This is possible if the process is not +// relocatable or dynamically linked. +// +// an alternative is to look at the PC if we can be sure +// that we have connected when the process is at the entry point. +// I dont think that is reliable for us. +addr_t +DynamicLoaderHexagonDYLD::GetEntryPoint() +{ + if (m_entry_point != LLDB_INVALID_ADDRESS) + return m_entry_point; + // check we have a valid process + if ( m_process == nullptr ) + return LLDB_INVALID_ADDRESS; + // Get the current executable module + Module & module = *( m_process->GetTarget( ).GetExecutableModule( ).get( ) ); + // Get the object file (elf file) for this module + lldb_private::ObjectFile &object = *( module.GetObjectFile( ) ); + // Check if the file is executable (ie, not shared object or relocatable) + if ( object.IsExecutable() ) + { + // Get the entry point address for this object + lldb_private::Address entry = object.GetEntryPointAddress( ); + // Return the entry point address + return entry.GetFileAddress( ); + } + // No idea so back out + return LLDB_INVALID_ADDRESS; +} + +const SectionList * +DynamicLoaderHexagonDYLD::GetSectionListFromModule(const ModuleSP module) const +{ + SectionList *sections = nullptr; + if (module.get()) + { + ObjectFile *obj_file = module->GetObjectFile(); + if (obj_file) + { + sections = obj_file->GetSectionList(); + } + } + return sections; +} + +static int ReadInt(Process *process, addr_t addr) +{ + Error error; + int value = (int)process->ReadUnsignedIntegerFromMemory(addr, sizeof(uint32_t), 0, error); + if (error.Fail()) + return -1; + else + return value; +} + +lldb::addr_t +DynamicLoaderHexagonDYLD::GetThreadLocalData (const lldb::ModuleSP module, const lldb::ThreadSP thread) +{ + auto it = m_loaded_modules.find (module); + if (it == m_loaded_modules.end()) + return LLDB_INVALID_ADDRESS; + + addr_t link_map = it->second; + if (link_map == LLDB_INVALID_ADDRESS) + return LLDB_INVALID_ADDRESS; + + const HexagonDYLDRendezvous::ThreadInfo &metadata = m_rendezvous.GetThreadInfo(); + if (!metadata.valid) + return LLDB_INVALID_ADDRESS; + + // Get the thread pointer. + addr_t tp = thread->GetThreadPointer (); + if (tp == LLDB_INVALID_ADDRESS) + return LLDB_INVALID_ADDRESS; + + // Find the module's modid. + int modid = ReadInt (m_process, link_map + metadata.modid_offset); + if (modid == -1) + return LLDB_INVALID_ADDRESS; + + // Lookup the DTV stucture for this thread. + addr_t dtv_ptr = tp + metadata.dtv_offset; + addr_t dtv = ReadPointer (dtv_ptr); + if (dtv == LLDB_INVALID_ADDRESS) + return LLDB_INVALID_ADDRESS; + + // Find the TLS block for this module. + addr_t dtv_slot = dtv + metadata.dtv_slot_size*modid; + addr_t tls_block = ReadPointer (dtv_slot + metadata.tls_offset); + + Module *mod = module.get(); + Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER)); + if (log) + log->Printf("DynamicLoaderHexagonDYLD::Performed TLS lookup: " + "module=%s, link_map=0x%" PRIx64 ", tp=0x%" PRIx64 ", modid=%i, tls_block=0x%" PRIx64, + mod->GetObjectName().AsCString(""), link_map, tp, modid, tls_block); + + return tls_block; +} |
