[Lldb-commits] [lldb] [lldb][FreeBSD] Add dynamic loader handle class for FreeBSD Kernel (PR #67106)
Alex Langford via lldb-commits
lldb-commits at lists.llvm.org
Fri Sep 22 15:50:31 PDT 2023
================
@@ -0,0 +1,770 @@
+#include "lldb/Breakpoint/StoppointCallbackContext.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleSpec.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/Section.h"
+#include "lldb/Core/StreamFile.h"
+#include "lldb/Interpreter/OptionValueProperties.h"
+#include "lldb/Symbol/LocateSymbolFile.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Target/OperatingSystem.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Target/ThreadPlanRunToAddress.h"
+#include "lldb/Utility/DataBuffer.h"
+#include "lldb/Utility/DataBufferHeap.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/State.h"
+
+#include "Plugins/ObjectFile/ELF/ObjectFileELF.h"
+
+#include "DynamicLoaderFreeBSDKernel.h"
+#include <memory>
+#include <mutex>
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE(DynamicLoaderFreeBSDKernel)
+
+void DynamicLoaderFreeBSDKernel::Initialize() {
+ PluginManager::RegisterPlugin(GetPluginNameStatic(),
+ GetPluginDescriptionStatic(), CreateInstance,
+ DebuggerInit);
+}
+
+void DynamicLoaderFreeBSDKernel::Terminate() {
+ PluginManager::UnregisterPlugin(CreateInstance);
+}
+
+llvm::StringRef DynamicLoaderFreeBSDKernel::GetPluginDescriptionStatic() {
+ return "The Dynamic Loader Plugin For FreeBSD Kernel";
+}
+
+static bool is_kernel(Module *module) {
+ if (!module)
+ return false;
+
+ ObjectFile *objfile = module->GetObjectFile();
+ if (!objfile)
+ return false;
+ if (objfile->GetType() != ObjectFile::eTypeExecutable)
+ return false;
+ if (objfile->GetStrata() != ObjectFile::eStrataUnknown &&
+ objfile->GetStrata() != ObjectFile::eStrataUser)
+ return false;
+
+ return true;
+}
+
+static bool is_kmod(Module *module) {
+ if (!module)
+ return false;
+ if (!module->GetObjectFile())
+ return false;
+ ObjectFile *objfile = module->GetObjectFile();
+ if (objfile->GetType() != ObjectFile::eTypeObjectFile &&
+ objfile->GetType() != ObjectFile::eTypeSharedLibrary)
+ return false;
+
+ return true;
+}
+
+static bool is_reloc(Module *module) {
+ if (!module)
+ return false;
+ if (!module->GetObjectFile())
+ return false;
+ ObjectFile *objfile = module->GetObjectFile();
+ if (objfile->GetType() != ObjectFile::eTypeObjectFile)
+ return false;
+
+ return true;
+}
+
+// Instantiate Function of the FreeBSD Kernel Dynamic Loader Plugin called when
+// Register the Plugin
+DynamicLoader *
+DynamicLoaderFreeBSDKernel::CreateInstance(lldb_private::Process *process,
+ bool force) {
+ // Check the environment when the plugin is not force loaded
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+ LLDB_LOGF(log, "DynamicLoaderFreeBSDKernel::CreateInstance: "
+ "Try to create instance");
+ if (!force) {
+ Module *exec = process->GetTarget().GetExecutableModulePointer();
+ // Check if the target is kernel
+ if (exec && !is_kernel(exec)) {
+ return nullptr;
+ }
+
+ const llvm::Triple &triple_ref =
+ process->GetTarget().GetArchitecture().GetTriple();
+ if (!triple_ref.isOSFreeBSD()) {
+ return nullptr;
+ }
+ }
+
+ // At this point we have checked the target is a FreeBSD kernel and all we
+ // have to do is to find the kernel address
+ const addr_t kernel_address = FindFreeBSDKernel(process);
+
+ if (CheckForKernelImageAtAddress(process, kernel_address).IsValid())
+ return new DynamicLoaderFreeBSDKernel(process, kernel_address);
+
+ return nullptr;
+}
+
+addr_t
+DynamicLoaderFreeBSDKernel::FindFreeBSDKernel(lldb_private::Process *process) {
+ addr_t kernel_addr = process->GetImageInfoAddress();
+ if (kernel_addr == LLDB_INVALID_ADDRESS)
+ kernel_addr = FindKernelAtLoadAddress(process);
+ return kernel_addr;
+}
+
+// Get the kernel address if the kernel is not loaded with a slide
+addr_t DynamicLoaderFreeBSDKernel::FindKernelAtLoadAddress(
+ lldb_private::Process *process) {
+ Module *exe_module = process->GetTarget().GetExecutableModulePointer();
+
+ if (!is_kernel(exe_module))
+ return LLDB_INVALID_ADDRESS;
+
+ ObjectFile *exe_objfile = exe_module->GetObjectFile();
+
+ if (!exe_objfile->GetBaseAddress().IsValid())
+ return LLDB_INVALID_ADDRESS;
+
+ if (CheckForKernelImageAtAddress(
+ process, exe_objfile->GetBaseAddress().GetFileAddress())
+ .IsValid())
+ return exe_objfile->GetBaseAddress().GetFileAddress();
+
+ return LLDB_INVALID_ADDRESS;
+}
+
+// Read ELF header from memry and return
+bool DynamicLoaderFreeBSDKernel::ReadELFHeader(Process *process,
+ lldb::addr_t addr,
+ llvm::ELF::Elf32_Ehdr &header,
+ bool *read_error) {
+ Status error;
+ if (read_error)
+ *read_error = false;
+
+ if (process->ReadMemory(addr, &header, sizeof(header), error) !=
+ sizeof(header)) {
+ if (read_error)
+ *read_error = true;
+ return false;
+ }
+
+ if (!header.checkMagic())
+ return false;
+
+ return true;
+}
+
+// Check the correctness of Kernel and return UUID
+lldb_private::UUID DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress(
+ Process *process, lldb::addr_t addr, bool *read_error) {
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+
+ if (addr == LLDB_INVALID_ADDRESS) {
+ if (read_error)
+ *read_error = true;
+ return UUID();
+ }
+
+ LLDB_LOGF(log,
+ "DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress: "
+ "looking for kernel binary at 0x%" PRIx64,
+ addr);
+
+ llvm::ELF::Elf32_Ehdr header;
+ if (!ReadELFHeader(process, addr, header))
+ return UUID();
+
+ // Check header type
+ if (header.e_type != llvm::ELF::ET_EXEC)
+ return UUID();
+
+ ModuleSP memory_module_sp =
+ process->ReadModuleFromMemory(FileSpec("temp_freebsd_kernel"), addr);
+ if (!memory_module_sp.get())
+ return UUID();
+
+ ObjectFile *exe_objfile = memory_module_sp->GetObjectFile();
+ if (exe_objfile == nullptr) {
+ LLDB_LOGF(log,
+ "DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress "
+ "found a binary at 0x%" PRIx64
+ " but could not create an object file from memory",
+ addr);
+ return UUID();
+ }
+
+ if (is_kernel(memory_module_sp.get())) {
+ ArchSpec kernel_arch(
+ llvm::ELF::convertEMachineToArchName(header.e_machine));
+
+ if (!process->GetTarget().GetArchitecture().IsCompatibleMatch(kernel_arch))
+ process->GetTarget().SetArchitecture(kernel_arch);
+
+ if (log) {
+ std::string uuid_str;
+ if (memory_module_sp->GetUUID().IsValid()) {
+ uuid_str = "with UUID ";
+ uuid_str += memory_module_sp->GetUUID().GetAsString();
+ } else {
+ uuid_str = "and no LC_UUID found in load commands ";
+ }
+ LLDB_LOGF(log,
+ "DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress: "
+ "kernel binary image found at 0x%" PRIx64 " with arch '%s' %s",
+ addr, kernel_arch.GetTriple().str().c_str(), uuid_str.c_str());
+ }
+
+ return memory_module_sp->GetUUID();
+ }
+
+ return UUID();
+}
+
+void DynamicLoaderFreeBSDKernel::DebuggerInit(
+ lldb_private::Debugger &debugger) {}
+
+DynamicLoaderFreeBSDKernel::DynamicLoaderFreeBSDKernel(Process *process,
+ addr_t kernel_address)
+ : DynamicLoader(process), m_process(process),
+ m_linker_file_list_struct_addr(LLDB_INVALID_ADDRESS),
+ m_linker_file_head_addr(LLDB_INVALID_ADDRESS),
+ m_kernel_load_address(kernel_address), m_mutex() {
+ process->SetCanRunCode(false);
+}
+
+DynamicLoaderFreeBSDKernel::~DynamicLoaderFreeBSDKernel() { Clear(true); }
+
+void DynamicLoaderFreeBSDKernel::Update() {
+ LoadKernelModules();
+ SetNotificationBreakPoint();
+}
+
+// Create in memory Module at the load address
+bool DynamicLoaderFreeBSDKernel::KModImageInfo::ReadMemoryModule(
+ lldb_private::Process *process) {
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+ if (m_memory_module_sp)
+ return true;
+ if (m_load_address == LLDB_INVALID_ADDRESS)
+ return false;
+
+ FileSpec file_spec(m_name.c_str());
+
+ ModuleSP memory_module_sp;
+
+ llvm::ELF::Elf32_Ehdr elf_eheader;
+ size_t size_to_read = 512;
+
+ if (ReadELFHeader(process, m_load_address, elf_eheader)) {
+ if (elf_eheader.e_ident[llvm::ELF::EI_CLASS] == llvm::ELF::ELFCLASS32) {
+ size_to_read = sizeof(llvm::ELF::Elf32_Ehdr) +
+ elf_eheader.e_phnum * elf_eheader.e_phentsize;
+ } else if (elf_eheader.e_ident[llvm::ELF::EI_CLASS] ==
+ llvm::ELF::ELFCLASS64) {
+ llvm::ELF::Elf64_Ehdr elf_eheader;
+ Status error;
+ if (process->ReadMemory(m_load_address, &elf_eheader, sizeof(elf_eheader),
+ error) == sizeof(elf_eheader))
+ size_to_read = sizeof(llvm::ELF::Elf64_Ehdr) +
+ elf_eheader.e_phnum * elf_eheader.e_phentsize;
+ }
+ }
+
+ memory_module_sp =
+ process->ReadModuleFromMemory(file_spec, m_load_address, size_to_read);
+
+ if (!memory_module_sp)
+ return false;
+
+ bool this_is_kernel = is_kernel(memory_module_sp.get());
+
+ if (!m_uuid.IsValid() && memory_module_sp->GetUUID().IsValid())
+ m_uuid = memory_module_sp->GetUUID();
+
+ m_memory_module_sp = memory_module_sp;
+ m_is_kernel = this_is_kernel;
+
+ // The kernel binary is from memory
+ if (this_is_kernel) {
+ if (log)
+ LLDB_LOGF(log,
+ "KextImageInfo::ReadMemoryModule read the kernel binary out "
+ "of memory");
+
+ if (memory_module_sp->GetArchitecture().IsValid())
+ process->GetTarget().SetArchitecture(memory_module_sp->GetArchitecture());
+ }
+
+ return true;
+}
+
+bool DynamicLoaderFreeBSDKernel::KModImageInfo::LoadImageUsingMemoryModule(
+ lldb_private::Process *process) {
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+
+ if (IsLoaded())
+ return true;
+
+ Target &target = process->GetTarget();
+
+ if (IsKernel() && m_uuid.IsValid()) {
+ Stream &s = target.GetDebugger().GetOutputStream();
+ s.Printf("Kernel UUID: %s\n", m_uuid.GetAsString().c_str());
+ s.Printf("Load Address: 0x%" PRIx64 "\n", m_load_address);
+ }
+
+ // Test if the module is loaded into the taget,
+ // maybe the module is loaded manually by user by doing target module add
+ // So that we have to create the module manually
+ if (!m_module_sp) {
+ const ModuleList &target_images = target.GetImages();
+ m_module_sp = target_images.FindModule(m_uuid);
+
+ // Search in the file system
+ if (!m_module_sp) {
+ ModuleSpec module_spec(FileSpec(GetPath()), target.GetArchitecture());
+ if (IsKernel()) {
+ Status error;
+ if (Symbols::DownloadObjectAndSymbolFile(module_spec, error, true)) {
+ if (FileSystem::Instance().Exists(module_spec.GetFileSpec()))
+ m_module_sp = std::make_shared<Module>(module_spec.GetFileSpec(),
+ target.GetArchitecture());
+ }
+ }
+
+ if (!m_module_sp)
+ m_module_sp = target.GetOrCreateModule(module_spec, true);
+ if (IsKernel() && !m_module_sp) {
+ Stream &s = target.GetDebugger().GetOutputStream();
+ s.Printf("WARNING: Unable to locate kernel binary on the debugger "
+ "system.\n");
+ }
+ }
+
+ if (m_module_sp) {
+ // If the file is not kernel or kmod, the target should be loaded once and
+ // don't reload again
+ if (!IsKernel() && !is_kmod(m_module_sp.get())) {
+ ModuleSP existing_module_sp = target.GetImages().FindModule(m_uuid);
+ if (existing_module_sp &&
+ existing_module_sp->IsLoadedInTarget(&target)) {
+ LLDB_LOGF(log,
+ "'%s' with UUID %s is not a kmod or kernel, and is "
+ "already registered in target, not loading.",
+ m_name.c_str(), m_uuid.GetAsString().c_str());
+ return true;
+ }
+ }
+ m_uuid = m_module_sp->GetUUID();
+
+ // or append to the images
+ target.GetImages().AppendIfNeeded(m_module_sp, false);
+ }
+ }
+
+ // If this file is relocatable kernel module(x86_64), adjust it's
+ // section(PT_LOAD segment) and return Because the kernel module's load
+ // address is the text section. lldb cannot create full memory module upon
+ // relocatable file So what we do is to set the load address only.
+ if (is_kmod(m_module_sp.get()) && is_reloc(m_module_sp.get())) {
+ m_stop_id = process->GetStopID();
+ bool changed;
+ m_module_sp->SetLoadAddress(target, m_load_address, true, changed);
+ return true;
+ }
+
+ if (m_module_sp)
+ ReadMemoryModule(process);
+
+ // Calculate the slides of in memory module
+ if (!m_memory_module_sp || !m_module_sp) {
+ m_module_sp.reset();
+ return false;
+ }
+
+ ObjectFile *ondisk_object_file = m_module_sp->GetObjectFile();
+ ObjectFile *memory_object_file = m_memory_module_sp->GetObjectFile();
+
+ if (!ondisk_object_file || !memory_object_file)
+ m_module_sp.reset();
+
+ // Find the slide address
+ addr_t fixed_slide = LLDB_INVALID_ADDRESS;
+ if (ObjectFileELF *memory_objfile_elf =
+ llvm::dyn_cast<ObjectFileELF>(memory_object_file)) {
+ addr_t load_address = memory_object_file->GetBaseAddress().GetFileAddress();
+
+ if (load_address != LLDB_INVALID_ADDRESS &&
+ m_load_address != load_address) {
+ fixed_slide = m_load_address - load_address;
+ LLDB_LOGF(log,
+ "kmod %s in-memory LOAD vmaddr is not correct, using a "
+ "fixed slide of 0x%" PRIx64,
+ m_name.c_str(), fixed_slide);
+ }
+ }
+
+ SectionList *ondisk_section_list = ondisk_object_file->GetSectionList();
+ SectionList *memory_section_list = memory_object_file->GetSectionList();
+
+ if (memory_section_list && ondisk_object_file) {
+ const uint32_t num_ondisk_sections = ondisk_section_list->GetSize();
+ uint32_t num_load_sections = 0;
+
+ for (uint32_t section_idx = 0; section_idx < num_ondisk_sections;
+ ++section_idx) {
+ SectionSP on_disk_section_sp =
+ ondisk_section_list->GetSectionAtIndex(section_idx);
+
+ if (!on_disk_section_sp)
+ continue;
+ if (fixed_slide != LLDB_INVALID_ADDRESS) {
+ target.SetSectionLoadAddress(on_disk_section_sp,
+ on_disk_section_sp->GetFileAddress() +
+ fixed_slide);
+
+ } else {
+ const Section *memory_section =
+ memory_section_list
+ ->FindSectionByName(on_disk_section_sp->GetName())
+ .get();
+ if (memory_section) {
+ target.SetSectionLoadAddress(on_disk_section_sp,
+ memory_section->GetFileAddress());
+ ++num_load_sections;
+ }
+ }
+ }
+
+ if (num_load_sections)
+ m_stop_id = process->GetStopID();
+ else
+ m_module_sp.reset();
+ } else {
+ m_module_sp.reset();
+ }
+
+ if (IsLoaded() && m_module_sp && IsKernel()) {
+ Stream &s = target.GetDebugger().GetOutputStream();
+ ObjectFile *kernel_object_file = m_module_sp->GetObjectFile();
+ if (kernel_object_file) {
+ addr_t file_address =
+ kernel_object_file->GetBaseAddress().GetFileAddress();
+ if (m_load_address != LLDB_INVALID_ADDRESS &&
+ file_address != LLDB_INVALID_ADDRESS) {
+ s.Printf("Kernel slide 0x%" PRIx64 " in memory.\n",
+ m_load_address - file_address);
+ s.Printf("Loaded kernel file %s\n",
+ m_module_sp->GetFileSpec().GetPath().c_str());
+ }
+ }
+ s.Flush();
+ }
+
+ return IsLoaded();
+}
+
+// This function is work for kernel file, others it wil reset load address and
+// return false
+bool DynamicLoaderFreeBSDKernel::KModImageInfo::LoadImageUsingFileAddress(
+ lldb_private::Process *process) {
+ if (IsLoaded())
+ return true;
+
+ if (m_module_sp) {
+ bool changed = false;
+ if (m_module_sp->SetLoadAddress(process->GetTarget(), 0, true, changed))
+ m_stop_id = process->GetStopID();
+ }
+
+ return false;
+}
+
+// Get the head of found_list
+bool DynamicLoaderFreeBSDKernel::ReadKmodsListHeader() {
+ std::lock_guard<decltype(m_mutex)> guard(m_mutex);
+
+ if (m_linker_file_list_struct_addr.IsValid()) {
+ // Get tqh_first struct element from linker_files
+ Status error;
+ addr_t address = m_process->ReadPointerFromMemory(
+ m_linker_file_list_struct_addr.GetLoadAddress(&m_process->GetTarget()),
+ error);
+ if (address != LLDB_INVALID_ADDRESS && error.Success()) {
+ m_linker_file_head_addr = Address(address);
+ } else {
+ m_linker_file_list_struct_addr.Clear();
+ return false;
+ }
+
+ if (!m_linker_file_head_addr.IsValid() ||
+ m_linker_file_head_addr.GetFileAddress() == 0) {
+ m_linker_file_list_struct_addr.Clear();
+ return false;
+ }
+ }
+ return true;
+}
+
+// Parse Kmod info in found_list
+bool DynamicLoaderFreeBSDKernel::ParseKmods(Address linker_files_head_addr) {
+ std::lock_guard<decltype(m_mutex)> guard(m_mutex);
+ KModImageInfo::collection_type linker_files_list;
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+
+ if (!ReadAllKmods(linker_files_head_addr, linker_files_list))
+ return false;
+ LLDB_LOGF(
+ log,
+ "Kmod-changed breakpoint hit, there are %lu kernel modules currently.\n",
+ linker_files_list.size());
+
+ ModuleList &modules = m_process->GetTarget().GetImages();
+ ModuleList remove_modules;
+ ModuleList add_modules;
+
+ for (ModuleSP module : modules.Modules()) {
+ if (is_kernel(module.get()))
+ continue;
+ if (is_kmod(module.get()))
+ remove_modules.AppendIfNeeded(module);
+ }
+
+ m_process->GetTarget().ModulesDidUnload(remove_modules, false);
+
+ for (KModImageInfo &image_info : linker_files_list) {
+ if (m_kld_name_to_uuid.find(image_info.GetName()) !=
+ m_kld_name_to_uuid.end())
+ image_info.SetUUID(m_kld_name_to_uuid[image_info.GetName()]);
+ bool failed_to_load = false;
+ if (!image_info.LoadImageUsingMemoryModule(m_process)) {
+ image_info.LoadImageUsingFileAddress(m_process);
+ failed_to_load = true;
+ } else {
+ m_linker_files_list.push_back(image_info);
+ m_kld_name_to_uuid[image_info.GetName()] = image_info.GetUUID();
+ }
+
+ if (!failed_to_load)
+ add_modules.AppendIfNeeded(image_info.GetModule());
+ }
+ m_process->GetTarget().ModulesDidLoad(add_modules);
+ return true;
+}
+
+// Read all kmod from a given arrays of list
+bool DynamicLoaderFreeBSDKernel::ReadAllKmods(
+ Address linker_files_head_addr,
+ KModImageInfo::collection_type &kmods_list) {
+
+ // Get offset of next member and load address symbol
+ static ConstString kld_off_address_symbol_name("kld_off_address");
+ static ConstString kld_off_next_symbol_name("kld_off_next");
+ static ConstString kld_off_filename_symbol_name("kld_off_filename");
+ static ConstString kld_off_pathname_symbol_name("kld_off_pathname");
+ const Symbol *kld_off_address_symbol =
+ m_kernel_image_info.GetModule()->FindFirstSymbolWithNameAndType(
+ kld_off_address_symbol_name, eSymbolTypeData);
+ const Symbol *kld_off_next_symbol =
+ m_kernel_image_info.GetModule()->FindFirstSymbolWithNameAndType(
+ kld_off_next_symbol_name, eSymbolTypeData);
+ const Symbol *kld_off_filename_symbol =
+ m_kernel_image_info.GetModule()->FindFirstSymbolWithNameAndType(
+ kld_off_filename_symbol_name, eSymbolTypeData);
+ const Symbol *kld_off_pathname_symbol =
+ m_kernel_image_info.GetModule()->FindFirstSymbolWithNameAndType(
+ kld_off_pathname_symbol_name, eSymbolTypeData);
+
+ if (!kld_off_address_symbol || !kld_off_next_symbol ||
+ !kld_off_filename_symbol || !kld_off_pathname_symbol)
+ return false;
+ Status error;
+ const int32_t kld_off_address = m_process->ReadSignedIntegerFromMemory(
+ kld_off_address_symbol->GetAddress().GetLoadAddress(
+ &m_process->GetTarget()),
+ 4, 0, error);
+ if (error.Fail())
+ return false;
+ const int32_t kld_off_next = m_process->ReadSignedIntegerFromMemory(
+ kld_off_next_symbol->GetAddress().GetLoadAddress(&m_process->GetTarget()),
+ 4, 0, error);
+ if (error.Fail())
+ return false;
+ const int32_t kld_off_filename = m_process->ReadSignedIntegerFromMemory(
+ kld_off_filename_symbol->GetAddress().GetLoadAddress(
+ &m_process->GetTarget()),
+ 4, 0, error);
+ if (error.Fail())
+ return false;
+
+ const int32_t kld_off_pathname = m_process->ReadSignedIntegerFromMemory(
+ kld_off_pathname_symbol->GetAddress().GetLoadAddress(
+ &m_process->GetTarget()),
+ 4, 0, error);
+ if (error.Fail())
+ return false;
+
+ // Parse KMods
+ addr_t kld_load_addr(LLDB_INVALID_ADDRESS);
+ char kld_filename[255];
+ char kld_pathname[255];
+ addr_t current_kld =
+ linker_files_head_addr.GetLoadAddress(&m_process->GetTarget());
+
+ while (current_kld != 0) {
+ m_process->ReadCStringFromMemory(
+ m_process->ReadPointerFromMemory(current_kld + kld_off_filename, error),
+ kld_filename, sizeof(kld_filename), error);
+ m_process->ReadCStringFromMemory(
+ m_process->ReadPointerFromMemory(current_kld + kld_off_pathname, error),
+ kld_pathname, sizeof(kld_pathname), error);
+ kld_load_addr =
+ m_process->ReadPointerFromMemory(current_kld + kld_off_address, error);
+
+ kmods_list.emplace_back();
+ KModImageInfo &kmod_info = kmods_list.back();
+ kmod_info.SetName(kld_filename);
+ kmod_info.SetLoadAddress(kld_load_addr);
+ kmod_info.SetPath(kld_pathname);
+ current_kld =
+ m_process->ReadPointerFromMemory(current_kld + kld_off_next, error);
+ if (kmod_info.GetName() == "kernel")
+ kmods_list.pop_back();
+ if (error.Fail())
+ return false;
+ }
+
+ return true;
+}
+
+// Read all kmods
+bool DynamicLoaderFreeBSDKernel::ReadAllKmods() {
+ std::lock_guard<decltype(m_mutex)> guard(m_mutex);
+
+ if (ReadKmodsListHeader()) {
+
+ if (m_linker_file_head_addr.IsValid()) {
+ if (!ParseKmods(m_linker_file_head_addr))
+ m_linker_files_list.clear();
+ return true;
+ }
+ }
+
+ return false;
+}
+
+// Load all Kernel Modules
+void DynamicLoaderFreeBSDKernel::LoadKernelModules() {
+ Log *log = GetLog(LLDBLog::DynamicLoader);
+ LLDB_LOGF(log, "DynamicLoaderFreeBSDKernel::LoadKernelModules "
+ "Start loading Kernel Module");
+
+ // Initialize Kernel Image Information at the first time
+ if (m_kernel_image_info.GetLoadAddress() == LLDB_INVALID_ADDRESS) {
+ ModuleSP module_sp = m_process->GetTarget().GetExecutableModule();
+ if (is_kernel(module_sp.get())) {
+ m_kernel_image_info.SetModule(module_sp);
+ m_kernel_image_info.SetIsKernel(true);
+ }
+
+ // Set name for kernel
+ ConstString kernel_name("freebsd_kernel");
----------------
bulbazord wrote:
Please avoid using `ConstString` unless you're calling a method which requires it. It looks like this is just to set a `std::string` in the `KModImageInfo` below. I'd recommend using `llvm::StringRef` here.
For context, anything you put into the `ConstString` string pool persists until LLDB exits. There is no way to reclaim that memory when you're done with it. This is useful in some cases (e.g. you have the same string a ton of times and will use them throughout the debug session). In this case, `kernel_name` only sticks around for a short amount of time.
https://github.com/llvm/llvm-project/pull/67106
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