1 files changed, 335 insertions, 0 deletions
diff --git a/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp b/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp
new file mode 100644
index 000000000000..635f99b4467d
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSDKernel/ProcessFreeBSDKernel.cpp
@@ -0,0 +1,335 @@
+//===-- ProcessFreeBSDKernel.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/Core/Module.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Target/DynamicLoader.h"
+
+#include "Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h"
+#include "ProcessFreeBSDKernel.h"
+#include "ThreadFreeBSDKernel.h"
+
+#if LLDB_ENABLE_FBSDVMCORE
+#include <fvc.h>
+#endif
+#if defined(__FreeBSD__)
+#include <kvm.h>
+#endif
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE(ProcessFreeBSDKernel)
+
+namespace {
+
+#if LLDB_ENABLE_FBSDVMCORE
+class ProcessFreeBSDKernelFVC : public ProcessFreeBSDKernel {
+public:
+  ProcessFreeBSDKernelFVC(lldb::TargetSP target_sp, lldb::ListenerSP listener,
+                          fvc_t *fvc, const FileSpec &core_file);
+
+  ~ProcessFreeBSDKernelFVC();
+
+  size_t DoReadMemory(lldb::addr_t addr, void *buf, size_t size,
+                      lldb_private::Status &error) override;
+
+private:
+  fvc_t *m_fvc;
+
+  const char *GetError();
+};
+#endif // LLDB_ENABLE_FBSDVMCORE
+
+#if defined(__FreeBSD__)
+class ProcessFreeBSDKernelKVM : public ProcessFreeBSDKernel {
+public:
+  ProcessFreeBSDKernelKVM(lldb::TargetSP target_sp, lldb::ListenerSP listener,
+                          kvm_t *fvc, const FileSpec &core_file);
+
+  ~ProcessFreeBSDKernelKVM();
+
+  size_t DoReadMemory(lldb::addr_t addr, void *buf, size_t size,
+                      lldb_private::Status &error) override;
+
+private:
+  kvm_t *m_kvm;
+
+  const char *GetError();
+};
+#endif // defined(__FreeBSD__)
+
+} // namespace
+
+ProcessFreeBSDKernel::ProcessFreeBSDKernel(lldb::TargetSP target_sp,
+                                           ListenerSP listener_sp,
+                                           const FileSpec &core_file)
+    : PostMortemProcess(target_sp, listener_sp, core_file) {}
+
+lldb::ProcessSP ProcessFreeBSDKernel::CreateInstance(lldb::TargetSP target_sp,
+                                                     ListenerSP listener_sp,
+                                                     const FileSpec *crash_file,
+                                                     bool can_connect) {
+  ModuleSP executable = target_sp->GetExecutableModule();
+  if (crash_file && !can_connect && executable) {
+#if LLDB_ENABLE_FBSDVMCORE
+    fvc_t *fvc =
+        fvc_open(executable->GetFileSpec().GetPath().c_str(),
+                 crash_file->GetPath().c_str(), nullptr, nullptr, nullptr);
+    if (fvc)
+      return std::make_shared<ProcessFreeBSDKernelFVC>(target_sp, listener_sp,
+                                                       fvc, *crash_file);
+#endif
+
+#if defined(__FreeBSD__)
+    kvm_t *kvm =
+        kvm_open2(executable->GetFileSpec().GetPath().c_str(),
+                  crash_file->GetPath().c_str(), O_RDONLY, nullptr, nullptr);
+    if (kvm)
+      return std::make_shared<ProcessFreeBSDKernelKVM>(target_sp, listener_sp,
+                                                       kvm, *crash_file);
+#endif
+  }
+  return nullptr;
+}
+
+void ProcessFreeBSDKernel::Initialize() {
+  static llvm::once_flag g_once_flag;
+
+  llvm::call_once(g_once_flag, []() {
+    PluginManager::RegisterPlugin(GetPluginNameStatic(),
+                                  GetPluginDescriptionStatic(), CreateInstance);
+  });
+}
+
+void ProcessFreeBSDKernel::Terminate() {
+  PluginManager::UnregisterPlugin(ProcessFreeBSDKernel::CreateInstance);
+}
+
+Status ProcessFreeBSDKernel::DoDestroy() { return Status(); }
+
+bool ProcessFreeBSDKernel::CanDebug(lldb::TargetSP target_sp,
+                                    bool plugin_specified_by_name) {
+  return true;
+}
+
+void ProcessFreeBSDKernel::RefreshStateAfterStop() {}
+
+bool ProcessFreeBSDKernel::DoUpdateThreadList(ThreadList &old_thread_list,
+                                              ThreadList &new_thread_list) {
+  if (old_thread_list.GetSize(false) == 0) {
+    // Make up the thread the first time this is called so we can set our one
+    // and only core thread state up.
+
+    // We cannot construct a thread without a register context as that crashes
+    // LLDB but we can construct a process without threads to provide minimal
+    // memory reading support.
+    switch (GetTarget().GetArchitecture().GetMachine()) {
+    case llvm::Triple::aarch64:
+    case llvm::Triple::x86:
+    case llvm::Triple::x86_64:
+      break;
+    default:
+      return false;
+    }
+
+    Status error;
+
+    // struct field offsets are written as symbols so that we don't have
+    // to figure them out ourselves
+    int32_t offset_p_list = ReadSignedIntegerFromMemory(
+        FindSymbol("proc_off_p_list"), 4, -1, error);
+    int32_t offset_p_pid =
+        ReadSignedIntegerFromMemory(FindSymbol("proc_off_p_pid"), 4, -1, error);
+    int32_t offset_p_threads = ReadSignedIntegerFromMemory(
+        FindSymbol("proc_off_p_threads"), 4, -1, error);
+    int32_t offset_p_comm = ReadSignedIntegerFromMemory(
+        FindSymbol("proc_off_p_comm"), 4, -1, error);
+
+    int32_t offset_td_tid = ReadSignedIntegerFromMemory(
+        FindSymbol("thread_off_td_tid"), 4, -1, error);
+    int32_t offset_td_plist = ReadSignedIntegerFromMemory(
+        FindSymbol("thread_off_td_plist"), 4, -1, error);
+    int32_t offset_td_pcb = ReadSignedIntegerFromMemory(
+        FindSymbol("thread_off_td_pcb"), 4, -1, error);
+    int32_t offset_td_oncpu = ReadSignedIntegerFromMemory(
+        FindSymbol("thread_off_td_oncpu"), 4, -1, error);
+    int32_t offset_td_name = ReadSignedIntegerFromMemory(
+        FindSymbol("thread_off_td_name"), 4, -1, error);
+
+    // fail if we were not able to read any of the offsets
+    if (offset_p_list == -1 || offset_p_pid == -1 || offset_p_threads == -1 ||
+        offset_p_comm == -1 || offset_td_tid == -1 || offset_td_plist == -1 ||
+        offset_td_pcb == -1 || offset_td_oncpu == -1 || offset_td_name == -1)
+      return false;
+
+    // dumptid contains the thread-id of the crashing thread
+    // dumppcb contains its PCB
+    int32_t dumptid =
+        ReadSignedIntegerFromMemory(FindSymbol("dumptid"), 4, -1, error);
+    lldb::addr_t dumppcb = FindSymbol("dumppcb");
+
+    // stoppcbs is an array of PCBs on all CPUs
+    // each element is of size pcb_size
+    int32_t pcbsize =
+        ReadSignedIntegerFromMemory(FindSymbol("pcb_size"), 4, -1, error);
+    lldb::addr_t stoppcbs = FindSymbol("stoppcbs");
+    // In later FreeBSD versions stoppcbs is a pointer to the array.
+    int32_t osreldate =
+        ReadSignedIntegerFromMemory(FindSymbol("osreldate"), 4, -1, error);
+    if (stoppcbs != LLDB_INVALID_ADDRESS && osreldate >= 1400089)
+        stoppcbs = ReadPointerFromMemory(stoppcbs, error);
+
+    // from FreeBSD sys/param.h
+    constexpr size_t fbsd_maxcomlen = 19;
+
+    // iterate through a linked list of all processes
+    // allproc is a pointer to the first list element, p_list field
+    // (found at offset_p_list) specifies the next element
+    for (lldb::addr_t proc =
+             ReadPointerFromMemory(FindSymbol("allproc"), error);
+         proc != 0 && proc != LLDB_INVALID_ADDRESS;
+         proc = ReadPointerFromMemory(proc + offset_p_list, error)) {
+      int32_t pid =
+          ReadSignedIntegerFromMemory(proc + offset_p_pid, 4, -1, error);
+      // process' command-line string
+      char comm[fbsd_maxcomlen + 1];
+      ReadCStringFromMemory(proc + offset_p_comm, comm, sizeof(comm), error);
+
+      // iterate through a linked list of all process' threads
+      // the initial thread is found in process' p_threads, subsequent
+      // elements are linked via td_plist field
+      for (lldb::addr_t td =
+               ReadPointerFromMemory(proc + offset_p_threads, error);
+           td != 0; td = ReadPointerFromMemory(td + offset_td_plist, error)) {
+        int32_t tid =
+            ReadSignedIntegerFromMemory(td + offset_td_tid, 4, -1, error);
+        lldb::addr_t pcb_addr =
+            ReadPointerFromMemory(td + offset_td_pcb, error);
+        // whether process was on CPU (-1 if not, otherwise CPU number)
+        int32_t oncpu =
+            ReadSignedIntegerFromMemory(td + offset_td_oncpu, 4, -2, error);
+        // thread name
+        char thread_name[fbsd_maxcomlen + 1];
+        ReadCStringFromMemory(td + offset_td_name, thread_name,
+                              sizeof(thread_name), error);
+
+        // if we failed to read TID, ignore this thread
+        if (tid == -1)
+          continue;
+
+        std::string thread_desc = llvm::formatv("(pid {0}) {1}", pid, comm);
+        if (*thread_name && strcmp(thread_name, comm)) {
+          thread_desc += '/';
+          thread_desc += thread_name;
+        }
+
+        // roughly:
+        // 1. if the thread crashed, its PCB is going to be at "dumppcb"
+        // 2. if the thread was on CPU, its PCB is going to be on the CPU
+        // 3. otherwise, its PCB is in the thread struct
+        if (tid == dumptid) {
+          // NB: dumppcb can be LLDB_INVALID_ADDRESS if reading it failed
+          pcb_addr = dumppcb;
+          thread_desc += " (crashed)";
+        } else if (oncpu != -1) {
+          // if we managed to read stoppcbs and pcb_size, use them to find
+          // the correct PCB
+          if (stoppcbs != LLDB_INVALID_ADDRESS && pcbsize > 0)
+            pcb_addr = stoppcbs + oncpu * pcbsize;
+          else
+            pcb_addr = LLDB_INVALID_ADDRESS;
+          thread_desc += llvm::formatv(" (on CPU {0})", oncpu);
+        }
+
+        ThreadSP thread_sp{
+            new ThreadFreeBSDKernel(*this, tid, pcb_addr, thread_desc)};
+        new_thread_list.AddThread(thread_sp);
+      }
+    }
+  } else {
+    const uint32_t num_threads = old_thread_list.GetSize(false);
+    for (uint32_t i = 0; i < num_threads; ++i)
+      new_thread_list.AddThread(old_thread_list.GetThreadAtIndex(i, false));
+  }
+  return new_thread_list.GetSize(false) > 0;
+}
+
+Status ProcessFreeBSDKernel::DoLoadCore() {
+  // The core is already loaded by CreateInstance().
+  return Status();
+}
+
+DynamicLoader *ProcessFreeBSDKernel::GetDynamicLoader() {
+  if (m_dyld_up.get() == nullptr)
+    m_dyld_up.reset(DynamicLoader::FindPlugin(
+        this, DynamicLoaderFreeBSDKernel::GetPluginNameStatic()));
+  return m_dyld_up.get();
+}
+
+lldb::addr_t ProcessFreeBSDKernel::FindSymbol(const char *name) {
+  ModuleSP mod_sp = GetTarget().GetExecutableModule();
+  const Symbol *sym = mod_sp->FindFirstSymbolWithNameAndType(ConstString(name));
+  return sym ? sym->GetLoadAddress(&GetTarget()) : LLDB_INVALID_ADDRESS;
+}
+
+#if LLDB_ENABLE_FBSDVMCORE
+
+ProcessFreeBSDKernelFVC::ProcessFreeBSDKernelFVC(lldb::TargetSP target_sp,
+                                                 ListenerSP listener_sp,
+                                                 fvc_t *fvc,
+                                                 const FileSpec &core_file)
+    : ProcessFreeBSDKernel(target_sp, listener_sp, crash_file), m_fvc(fvc) {}
+
+ProcessFreeBSDKernelFVC::~ProcessFreeBSDKernelFVC() {
+  if (m_fvc)
+    fvc_close(m_fvc);
+}
+
+size_t ProcessFreeBSDKernelFVC::DoReadMemory(lldb::addr_t addr, void *buf,
+                                             size_t size, Status &error) {
+  ssize_t rd = 0;
+  rd = fvc_read(m_fvc, addr, buf, size);
+  if (rd < 0 || static_cast<size_t>(rd) != size) {
+    error.SetErrorStringWithFormat("Reading memory failed: %s", GetError());
+    return rd > 0 ? rd : 0;
+  }
+  return rd;
+}
+
+const char *ProcessFreeBSDKernelFVC::GetError() { return fvc_geterr(m_fvc); }
+
+#endif // LLDB_ENABLE_FBSDVMCORE
+
+#if defined(__FreeBSD__)
+
+ProcessFreeBSDKernelKVM::ProcessFreeBSDKernelKVM(lldb::TargetSP target_sp,
+                                                 ListenerSP listener_sp,
+                                                 kvm_t *fvc,
+                                                 const FileSpec &core_file)
+    : ProcessFreeBSDKernel(target_sp, listener_sp, core_file), m_kvm(fvc) {}
+
+ProcessFreeBSDKernelKVM::~ProcessFreeBSDKernelKVM() {
+  if (m_kvm)
+    kvm_close(m_kvm);
+}
+
+size_t ProcessFreeBSDKernelKVM::DoReadMemory(lldb::addr_t addr, void *buf,
+                                             size_t size, Status &error) {
+  ssize_t rd = 0;
+  rd = kvm_read2(m_kvm, addr, buf, size);
+  if (rd < 0 || static_cast<size_t>(rd) != size) {
+    error.SetErrorStringWithFormat("Reading memory failed: %s", GetError());
+    return rd > 0 ? rd : 0;
+  }
+  return rd;
+}
+
+const char *ProcessFreeBSDKernelKVM::GetError() { return kvm_geterr(m_kvm); }
+
+#endif // defined(__FreeBSD__)