[Lldb-commits] [lldb] [lldb][FreeBSD] Add dynamic loader handle class for FreeBSD Kernel (PR #67106)

via lldb-commits lldb-commits at lists.llvm.org
Tue Sep 26 07:58:02 PDT 2023


https://github.com/aokblast updated https://github.com/llvm/llvm-project/pull/67106

>From f8ed3ed64be0a451542a4ec71f254dc9038b2d19 Mon Sep 17 00:00:00 2001
From: aokblast <i19670219111 at kimo.com>
Date: Fri, 22 Sep 2023 18:11:07 +0800
Subject: [PATCH 1/3] feat: add DynamicLoaderFreeBSDKernel

---
 .../Plugins/DynamicLoader/CMakeLists.txt      |   1 +
 .../FreeBSD-Kernel/CMakeLists.txt             |  13 +
 .../DynamicLoaderFreeBSDKernel.cpp            | 770 ++++++++++++++++++
 .../DynamicLoaderFreeBSDKernel.h              | 165 ++++
 .../FreeBSDKernel/ProcessFreeBSDKernel.cpp    |   4 +-
 5 files changed, 951 insertions(+), 2 deletions(-)
 create mode 100644 lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/CMakeLists.txt
 create mode 100644 lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
 create mode 100644 lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h

diff --git a/lldb/source/Plugins/DynamicLoader/CMakeLists.txt b/lldb/source/Plugins/DynamicLoader/CMakeLists.txt
index f357fea02efbe68..30607159acdc088 100644
--- a/lldb/source/Plugins/DynamicLoader/CMakeLists.txt
+++ b/lldb/source/Plugins/DynamicLoader/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_subdirectory(Darwin-Kernel)
+add_subdirectory(FreeBSD-Kernel)
 add_subdirectory(MacOSX-DYLD)
 add_subdirectory(POSIX-DYLD)
 add_subdirectory(Static)
diff --git a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/CMakeLists.txt b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/CMakeLists.txt
new file mode 100644
index 000000000000000..76daf0a327cf97b
--- /dev/null
+++ b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/CMakeLists.txt
@@ -0,0 +1,13 @@
+add_lldb_library(lldbPluginDynamicLoaderFreeBSDKernel PLUGIN
+  DynamicLoaderFreeBSDKernel.cpp
+
+  LINK_LIBS
+    lldbBreakpoint
+    lldbCore
+    lldbHost
+    lldbInterpreter
+    lldbSymbol
+    lldbTarget
+    lldbUtility
+    lldbPluginObjectFileELF
+  )
diff --git a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
new file mode 100644
index 000000000000000..d5eb891f0060bea
--- /dev/null
+++ b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
@@ -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");
+    module_sp = m_kernel_image_info.GetModule();
+    if (module_sp.get() && module_sp->GetObjectFile() &&
+        !module_sp->GetObjectFile()->GetFileSpec().GetFilename().IsEmpty())
+      kernel_name = module_sp->GetObjectFile()->GetFileSpec().GetFilename();
+    m_kernel_image_info.SetName(kernel_name.AsCString());
+
+    if (m_kernel_image_info.GetLoadAddress() == LLDB_INVALID_ADDRESS) {
+      m_kernel_image_info.SetLoadAddress(m_kernel_load_address);
+    }
+
+    // Build In memory Module
+    if (m_kernel_image_info.GetLoadAddress() != LLDB_INVALID_ADDRESS) {
+      // If the kernel is not loaded in the memory, use file to load
+      if (!m_kernel_image_info.LoadImageUsingMemoryModule(m_process))
+        m_kernel_image_info.LoadImageUsingFileAddress(m_process);
+    }
+  }
+
+  LoadOperatingSystemPlugin(false);
+
+  if (!m_kernel_image_info.IsLoaded() || !m_kernel_image_info.GetModule()) {
+    m_kernel_image_info.Clear();
+    return;
+  }
+
+  static ConstString modlist_symbol_name("linker_files");
+
+  const Symbol *symbol =
+      m_kernel_image_info.GetModule()->FindFirstSymbolWithNameAndType(
+          modlist_symbol_name, lldb::eSymbolTypeData);
+
+  if (symbol) {
+    m_linker_file_list_struct_addr = symbol->GetAddress();
+    ReadAllKmods();
+  } else {
+    LLDB_LOGF(log, "DynamicLoaderFreeBSDKernel::LoadKernelModules "
+                   "cannot file modlist symbol");
+  }
+}
+
+// Update symbol when use kldload by setting callback function on kldload
+void DynamicLoaderFreeBSDKernel::SetNotificationBreakPoint() {}
+
+// Hook called when attach to a process
+void DynamicLoaderFreeBSDKernel::DidAttach() {
+  PrivateInitialize(m_process);
+  Update();
+}
+
+// Hook called after attach to a process
+void DynamicLoaderFreeBSDKernel::DidLaunch() {
+  PrivateInitialize(m_process);
+  Update();
+}
+
+// Clear all member except kernel address
+void DynamicLoaderFreeBSDKernel::Clear(bool clear_process) {
+  std::lock_guard<decltype(m_mutex)> guard(m_mutex);
+  if (clear_process)
+    m_process = nullptr;
+  m_linker_file_head_addr.Clear();
+  m_linker_file_list_struct_addr.Clear();
+  m_kernel_image_info.Clear();
+  m_linker_files_list.clear();
+}
+
+// Reinitialize class
+void DynamicLoaderFreeBSDKernel::PrivateInitialize(Process *process) {
+  Clear(true);
+  m_process = process;
+}
+
+ThreadPlanSP DynamicLoaderFreeBSDKernel::GetStepThroughTrampolinePlan(
+    lldb_private::Thread &thread, bool stop_others) {
+  Log *log = GetLog(LLDBLog::Step);
+  LLDB_LOGF(log, "Could not find symbol for step through.");
+  return {};
+}
+
+Status DynamicLoaderFreeBSDKernel::CanLoadImage() {
+  Status error("shared object cannot be loaded into kernel");
+  return error;
+}
diff --git a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h
new file mode 100644
index 000000000000000..d8d32f91c6229bf
--- /dev/null
+++ b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h
@@ -0,0 +1,165 @@
+#ifndef LLDB_SOURCE_PLUGINS_DYNAMICLOADER_FREEBSD_KERNEL_DYNAMICLOADERFREEBSDKERNEL_H
+#define LLDB_SOURCE_PLUGINS_DYNAMICLOADER_FREEBSD_KERNEL_DYNAMICLOADERFREEBSDKERNEL_H
+
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include "lldb/Target/DynamicLoader.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Utility/FileSpec.h"
+#include "lldb/Utility/UUID.h"
+#include "llvm/BinaryFormat/ELF.h"
+
+class DynamicLoaderFreeBSDKernel : public lldb_private::DynamicLoader {
+public:
+  DynamicLoaderFreeBSDKernel(lldb_private::Process *process,
+                             lldb::addr_t kernel_addr);
+
+  ~DynamicLoaderFreeBSDKernel() override;
+
+  // Static Functions
+
+  static void Initialize();
+
+  static void Terminate();
+
+  static llvm::StringRef GetPluginNameStatic() {
+    return "DynamicLoaderFreeBSDKernel";
+  }
+
+  static llvm::StringRef GetPluginDescriptionStatic();
+
+  static lldb_private::DynamicLoader *
+  CreateInstance(lldb_private::Process *process, bool force);
+
+  static void DebuggerInit(lldb_private::Debugger &debugger);
+
+  static lldb::addr_t FindFreeBSDKernel(lldb_private::Process *process);
+
+  // Hooks for time point that after attach to some proccess
+  void DidAttach() override;
+
+  void DidLaunch() override;
+
+  lldb::ThreadPlanSP GetStepThroughTrampolinePlan(lldb_private::Thread &thread,
+                                                  bool stop_others) override;
+
+  lldb_private::Status CanLoadImage() override;
+
+  llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
+
+protected:
+  class KModImageInfo {
+  public:
+    KModImageInfo()
+        : m_module_sp(), m_memory_module_sp(), m_uuid(), m_name(), m_path() {}
+
+    void Clear() {
+      m_load_address = LLDB_INVALID_ADDRESS;
+      m_name.clear();
+      m_uuid.Clear();
+      m_module_sp.reset();
+      m_memory_module_sp.reset();
+      m_stop_id = UINT32_MAX;
+      m_path.clear();
+    }
+
+    void SetLoadAddress(lldb::addr_t load_address) {
+      m_load_address = load_address;
+    }
+
+    lldb::addr_t GetLoadAddress() const { return m_load_address; }
+
+    void SetUUID(const lldb_private::UUID uuid) { m_uuid = uuid; }
+
+    lldb_private::UUID GetUUID() const { return m_uuid; }
+
+    void SetName(const char *name) { m_name = name; }
+
+    std::string GetName() const { return m_name; }
+
+    void SetPath(const char *path) { m_path = path; }
+
+    std::string GetPath() const { return m_path; }
+
+    void SetModule(lldb::ModuleSP module) { m_module_sp = module; }
+
+    lldb::ModuleSP GetModule() { return m_module_sp; }
+
+    void SetIsKernel(bool is_kernel) { m_is_kernel = is_kernel; }
+
+    bool IsKernel() const { return m_is_kernel; };
+
+    void SetStopID(uint32_t stop_id) { m_stop_id = stop_id; }
+
+    uint32_t GetStopID() { return m_stop_id; }
+
+    bool IsLoaded() const { return m_stop_id != UINT32_MAX; };
+
+    bool ReadMemoryModule(lldb_private::Process *process);
+
+    bool LoadImageUsingMemoryModule(lldb_private::Process *process);
+
+    bool LoadImageUsingFileAddress(lldb_private::Process *process);
+
+    using collection_type = std::vector<KModImageInfo>;
+
+  private:
+    lldb::ModuleSP m_module_sp;
+    lldb::ModuleSP m_memory_module_sp;
+    lldb::addr_t m_load_address = LLDB_INVALID_ADDRESS;
+    lldb_private::UUID m_uuid;
+    bool m_is_kernel = false;
+    std::string m_name;
+    std::string m_path;
+    uint32_t m_stop_id = UINT32_MAX;
+  };
+
+  void PrivateInitialize(lldb_private::Process *process);
+
+  void Clear(bool clear_process);
+
+  void Update();
+
+  void LoadKernelModules();
+
+  bool ReadAllKmods();
+
+  bool ReadAllKmods(lldb_private::Address linker_files_head_address,
+                    KModImageInfo::collection_type &kmods_list);
+
+  bool ReadKmodsListHeader();
+
+  bool ParseKmods(lldb_private::Address linker_files_head_address);
+
+  void SetNotificationBreakPoint();
+
+  static lldb_private::UUID
+  CheckForKernelImageAtAddress(lldb_private::Process *process,
+                               lldb::addr_t address,
+                               bool *read_error = nullptr);
+
+  static lldb::addr_t FindKernelAtLoadAddress(lldb_private::Process *process);
+
+  static bool ReadELFHeader(lldb_private::Process *process,
+                            lldb::addr_t address, llvm::ELF::Elf32_Ehdr &header,
+                            bool *read_error = nullptr);
+
+  lldb_private::Process *m_process;
+  lldb_private::Address m_linker_file_list_struct_addr;
+  lldb_private::Address m_linker_file_head_addr;
+  lldb::addr_t m_kernel_load_address;
+  KModImageInfo m_kernel_image_info;
+  KModImageInfo::collection_type m_linker_files_list;
+  std::recursive_mutex m_mutex;
+  std::unordered_map<std::string, lldb_private::UUID> m_kld_name_to_uuid;
+
+private:
+  DynamicLoaderFreeBSDKernel(const DynamicLoaderFreeBSDKernel &) = delete;
+
+  const DynamicLoaderFreeBSDKernel &
+  operator=(const DynamicLoaderFreeBSDKernel &) = delete;
+};
+
+#endif
diff --git a/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp b/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp
index e3707365a9c3f19..601f5df43dbba4e 100644
--- a/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp
+++ b/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp
@@ -10,7 +10,7 @@
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Target/DynamicLoader.h"
 
-#include "Plugins/DynamicLoader/Static/DynamicLoaderStatic.h"
+#include "Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h"
 #include "ProcessFreeBSDKernel.h"
 #include "ThreadFreeBSDKernel.h"
 
@@ -262,7 +262,7 @@ Status ProcessFreeBSDKernel::DoLoadCore() {
 DynamicLoader *ProcessFreeBSDKernel::GetDynamicLoader() {
   if (m_dyld_up.get() == nullptr)
     m_dyld_up.reset(DynamicLoader::FindPlugin(
-        this, DynamicLoaderStatic::GetPluginNameStatic()));
+        this, DynamicLoaderFreeBSDKernel::GetPluginNameStatic()));
   return m_dyld_up.get();
 }
 

>From a61068e7ffe62023a62e958be6e69373e30a2382 Mon Sep 17 00:00:00 2001
From: aokblast <i19670219111 at kimo.com>
Date: Fri, 22 Sep 2023 20:09:01 +0800
Subject: [PATCH 2/3] feat: Support relocatable kernel module files so the
 section address of these files will assigned correctly

---
 .../Plugins/ObjectFile/ELF/ObjectFileELF.cpp    | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 2da971dff895b4a..0945ba71c1ad8e6 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -935,6 +935,16 @@ lldb_private::Address ObjectFileELF::GetEntryPointAddress() {
 }
 
 Address ObjectFileELF::GetBaseAddress() {
+  if (GetType() == ObjectFile::eTypeObjectFile) {
+    for (SectionHeaderCollIter I = std::next(m_section_headers.begin());
+         I != m_section_headers.end(); ++I) {
+      const ELFSectionHeaderInfo &header = *I;
+      if (header.sh_flags & SHF_ALLOC)
+        return Address(GetSectionList()->FindSectionByID(SectionIndex(I)), 0);
+    }
+    return LLDB_INVALID_ADDRESS;
+  }
+
   for (const auto &EnumPHdr : llvm::enumerate(ProgramHeaders())) {
     const ELFProgramHeader &H = EnumPHdr.value();
     if (H.p_type != PT_LOAD)
@@ -1764,7 +1774,12 @@ class VMAddressProvider {
   VMRange GetVMRange(const ELFSectionHeader &H) {
     addr_t Address = H.sh_addr;
     addr_t Size = H.sh_flags & SHF_ALLOC ? H.sh_size : 0;
-    if (ObjectType == ObjectFile::Type::eTypeObjectFile && Segments.empty() && (H.sh_flags & SHF_ALLOC)) {
+
+    // When this is a debug file for relocatable file, the address is all zero
+    // and thus needs to use accumulate method
+    if ((ObjectType == ObjectFile::Type::eTypeObjectFile ||
+         (ObjectType == ObjectFile::Type::eTypeDebugInfo && H.sh_addr == 0)) &&
+        Segments.empty() && (H.sh_flags & SHF_ALLOC)) {
       NextVMAddress =
           llvm::alignTo(NextVMAddress, std::max<addr_t>(H.sh_addralign, 1));
       Address = NextVMAddress;

>From f760aa7eaee87a00359cfcb478d1c6cb444b4f53 Mon Sep 17 00:00:00 2001
From: aokblast <i19670219111 at kimo.com>
Date: Tue, 26 Sep 2023 22:57:35 +0800
Subject: [PATCH 3/3] feat: fix all bug in comments

---
 .../DynamicLoaderFreeBSDKernel.cpp            | 125 ++++++++++--------
 .../DynamicLoaderFreeBSDKernel.h              |  15 ++-
 .../Plugins/ObjectFile/ELF/ObjectFileELF.cpp  |  23 +++-
 3 files changed, 102 insertions(+), 61 deletions(-)

diff --git a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
index d5eb891f0060bea..8e23a2faf65469e 100644
--- a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
+++ b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.cpp
@@ -1,3 +1,12 @@
+//===-- DynamicLoaderFreeBSDKernel.cpp
+//------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
 #include "lldb/Breakpoint/StoppointCallbackContext.h"
 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/Module.h"
@@ -55,7 +64,7 @@ static bool is_kernel(Module *module) {
   if (objfile->GetType() != ObjectFile::eTypeExecutable)
     return false;
   if (objfile->GetStrata() != ObjectFile::eStrataUnknown &&
-      objfile->GetStrata() != ObjectFile::eStrataUser)
+      objfile->GetStrata() != ObjectFile::eStrataKernel)
     return false;
 
   return true;
@@ -92,16 +101,12 @@ 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");
+  Module *exec = process->GetTarget().GetExecutableModulePointer();
+  if (exec && !is_kernel(exec)) {
+    return nullptr;
+  }
   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()) {
@@ -187,8 +192,10 @@ lldb_private::UUID DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress(
             addr);
 
   llvm::ELF::Elf32_Ehdr header;
-  if (!ReadELFHeader(process, addr, header))
+  if (!ReadELFHeader(process, addr, header)) {
+    *read_error = true;
     return UUID();
+  }
 
   // Check header type
   if (header.e_type != llvm::ELF::ET_EXEC)
@@ -196,8 +203,11 @@ lldb_private::UUID DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress(
 
   ModuleSP memory_module_sp =
       process->ReadModuleFromMemory(FileSpec("temp_freebsd_kernel"), addr);
-  if (!memory_module_sp.get())
+
+  if (!memory_module_sp.get()) {
+    *read_error = true;
     return UUID();
+  }
 
   ObjectFile *exe_objfile = memory_module_sp->GetObjectFile();
   if (exe_objfile == nullptr) {
@@ -209,31 +219,27 @@ lldb_private::UUID DynamicLoaderFreeBSDKernel::CheckForKernelImageAtAddress(
     return UUID();
   }
 
-  if (is_kernel(memory_module_sp.get())) {
-    ArchSpec kernel_arch(
-        llvm::ELF::convertEMachineToArchName(header.e_machine));
+  // In here, I should check is_kernel for memory_module_sp
+  // However, the ReadModuleFromMemory reads wrong section so that this check
+  // will failed
+  ArchSpec kernel_arch(llvm::ELF::convertEMachineToArchName(header.e_machine));
 
-    if (!process->GetTarget().GetArchitecture().IsCompatibleMatch(kernel_arch))
-      process->GetTarget().SetArchitecture(kernel_arch);
+  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();
+  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 UUID();
+  return memory_module_sp->GetUUID();
 }
 
 void DynamicLoaderFreeBSDKernel::DebuggerInit(
@@ -264,7 +270,7 @@ bool DynamicLoaderFreeBSDKernel::KModImageInfo::ReadMemoryModule(
   if (m_load_address == LLDB_INVALID_ADDRESS)
     return false;
 
-  FileSpec file_spec(m_name.c_str());
+  FileSpec file_spec(m_name);
 
   ModuleSP memory_module_sp;
 
@@ -302,10 +308,8 @@ bool DynamicLoaderFreeBSDKernel::KModImageInfo::ReadMemoryModule(
 
   // The kernel binary is from memory
   if (this_is_kernel) {
-    if (log)
-      LLDB_LOGF(log,
-                "KextImageInfo::ReadMemoryModule read the kernel binary out "
-                "of memory");
+    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());
@@ -384,7 +388,7 @@ bool DynamicLoaderFreeBSDKernel::KModImageInfo::LoadImageUsingMemoryModule(
   // 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;
+    bool changed = false;
     m_module_sp->SetLoadAddress(target, m_load_address, true, changed);
     return true;
   }
@@ -594,6 +598,7 @@ bool DynamicLoaderFreeBSDKernel::ReadAllKmods(
   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(
@@ -628,20 +633,34 @@ bool DynamicLoaderFreeBSDKernel::ReadAllKmods(
       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);
+    addr_t kld_filename_addr =
+        m_process->ReadPointerFromMemory(current_kld + kld_off_filename, error);
+    if (error.Fail())
+      return false;
+    addr_t kld_pathname_addr =
+        m_process->ReadPointerFromMemory(current_kld + kld_off_pathname, error);
+    if (error.Fail())
+      return false;
+
+    m_process->ReadCStringFromMemory(kld_filename_addr, kld_filename,
+                                     sizeof(kld_filename), error);
+    if (error.Fail())
+      return false;
+    m_process->ReadCStringFromMemory(kld_pathname_addr, kld_pathname,
+                                     sizeof(kld_pathname), error);
+    if (error.Fail())
+      return false;
     kld_load_addr =
         m_process->ReadPointerFromMemory(current_kld + kld_off_address, error);
+    if (error.Fail())
+      return false;
 
     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")
@@ -654,19 +673,15 @@ bool DynamicLoaderFreeBSDKernel::ReadAllKmods(
 }
 
 // Read all kmods
-bool DynamicLoaderFreeBSDKernel::ReadAllKmods() {
+void 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
@@ -684,12 +699,15 @@ void DynamicLoaderFreeBSDKernel::LoadKernelModules() {
     }
 
     // Set name for kernel
-    ConstString kernel_name("freebsd_kernel");
+    llvm::StringRef kernel_name("freebsd_kernel");
     module_sp = m_kernel_image_info.GetModule();
     if (module_sp.get() && module_sp->GetObjectFile() &&
         !module_sp->GetObjectFile()->GetFileSpec().GetFilename().IsEmpty())
-      kernel_name = module_sp->GetObjectFile()->GetFileSpec().GetFilename();
-    m_kernel_image_info.SetName(kernel_name.AsCString());
+      kernel_name = module_sp->GetObjectFile()
+                        ->GetFileSpec()
+                        .GetFilename()
+                        .GetStringRef();
+    m_kernel_image_info.SetName(kernel_name.data());
 
     if (m_kernel_image_info.GetLoadAddress() == LLDB_INVALID_ADDRESS) {
       m_kernel_image_info.SetLoadAddress(m_kernel_load_address);
@@ -760,7 +778,8 @@ void DynamicLoaderFreeBSDKernel::PrivateInitialize(Process *process) {
 ThreadPlanSP DynamicLoaderFreeBSDKernel::GetStepThroughTrampolinePlan(
     lldb_private::Thread &thread, bool stop_others) {
   Log *log = GetLog(LLDBLog::Step);
-  LLDB_LOGF(log, "Could not find symbol for step through.");
+  LLDB_LOGF(log, "DynamicLoaderFreeBSDKernel::GetStepThroughTrampolinePlan is "
+                 "not yet implemented.");
   return {};
 }
 
diff --git a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h
index d8d32f91c6229bf..05c938defe2a2b8 100644
--- a/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h
+++ b/lldb/source/Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h
@@ -1,3 +1,12 @@
+//===-- DynamicLoaderFreeBSDKernel.h
+//------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
 #ifndef LLDB_SOURCE_PLUGINS_DYNAMICLOADER_FREEBSD_KERNEL_DYNAMICLOADERFREEBSDKERNEL_H
 #define LLDB_SOURCE_PLUGINS_DYNAMICLOADER_FREEBSD_KERNEL_DYNAMICLOADERFREEBSDKERNEL_H
 
@@ -24,9 +33,7 @@ class DynamicLoaderFreeBSDKernel : public lldb_private::DynamicLoader {
 
   static void Terminate();
 
-  static llvm::StringRef GetPluginNameStatic() {
-    return "DynamicLoaderFreeBSDKernel";
-  }
+  static llvm::StringRef GetPluginNameStatic() { return "freebsd-kernel"; }
 
   static llvm::StringRef GetPluginDescriptionStatic();
 
@@ -124,7 +131,7 @@ class DynamicLoaderFreeBSDKernel : public lldb_private::DynamicLoader {
 
   void LoadKernelModules();
 
-  bool ReadAllKmods();
+  void ReadAllKmods();
 
   bool ReadAllKmods(lldb_private::Address linker_files_head_address,
                     KModImageInfo::collection_type &kmods_list);
diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 0945ba71c1ad8e6..bc17e97d45b158c 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -3469,10 +3469,25 @@ ObjectFile::Strata ObjectFileELF::CalculateStrata() {
 
   case llvm::ELF::ET_EXEC:
     // 2 - Executable file
-    // TODO: is there any way to detect that an executable is a kernel
-    // related executable by inspecting the program headers, section headers,
-    // symbols, or any other flag bits???
-    return eStrataUser;
+        {
+      SectionList *section_list = GetSectionList();
+      if (section_list) {
+        static ConstString loader_section_name(".interp");
+        SectionSP loader_section = section_list->FindSectionByName(loader_section_name);
+        if (loader_section) {
+          char buffer[256];
+          size_t read_size = ReadSectionData(loader_section.get(), 0, buffer, sizeof(buffer));
+
+          // We compare the content of .interp section
+          // It will contains \0 when counting read_size, so the size needs to decrease by one
+          llvm::StringRef loader_name(buffer, read_size - 1);
+          llvm::StringRef freebsd_kernel_loader_name("/red/herring");
+          if (loader_name.equals(freebsd_kernel_loader_name))
+            return eStrataKernel;
+        }
+      }
+      return eStrataUser;
+    }
 
   case llvm::ELF::ET_DYN:
     // 3 - Shared object file



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