[lldb/platform-gdb] Clear cached protocol state upon disconnection

Previously we would persist the flags indicating whether the remote side supports a particular feature across reconnects, which is obviously not a good idea. I implement the clearing by nuking (its the only way to be sure :) the entire GDBRemoteCommunication object in the disconnect operation and creating a new one upon connection. This allows us to maintain a nice invariant that the GDBRemoteCommunication object (which is now a pointer) exists only if it is connected. The downside to that is that a lot of functions now needs to check the validity of the pointer instead of blindly accessing the object. The process communication does not suffer from the same issue because we always destroy the entire Process object for a relaunch. Differential Revision: https://reviews.llvm.org/D116539
2026-02-06 06:31:50 +08:00 · 2022-01-03 16:49:58 +01:00
parent d0ee094d6a
commit 8ccfcab34f
5 changed files with 142 additions and 63 deletions
--- a/lldb/packages/Python/lldbsuite/test/lldbgdbclient.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbgdbclient.py
@@ -58,7 +58,7 @@ class GDBRemoteTestBase(TestBase):
        self.assertTrue(process, PROCESS_IS_VALID)
        return process

-    def assertPacketLogContains(self, packets):
+    def assertPacketLogContains(self, packets, log=None):
        """
        Assert that the mock server's packet log contains the given packets.

@@ -69,9 +69,10 @@ class GDBRemoteTestBase(TestBase):
        The check does not require that the packets be consecutive, but does
        require that they are ordered in the log as they ordered in the arg.
        """
+        if log is None:
+            log = self.server.responder.packetLog
        i = 0
        j = 0
-        log = self.server.responder.packetLog

        while i < len(packets) and j < len(log):
            if log[j] == packets[i]:
--- a/lldb/source/Plugins/Platform/Android/PlatformAndroidRemoteGDBServer.cpp
+++ b/lldb/source/Plugins/Platform/Android/PlatformAndroidRemoteGDBServer.cpp
@@ -82,9 +82,11 @@ PlatformAndroidRemoteGDBServer::~PlatformAndroidRemoteGDBServer() {

 bool PlatformAndroidRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
                                                     std::string &connect_url) {
+  assert(IsConnected());
  uint16_t remote_port = 0;
  std::string socket_name;
-  if (!m_gdb_client.LaunchGDBServer("127.0.0.1", pid, remote_port, socket_name))
+  if (!m_gdb_client_up->LaunchGDBServer("127.0.0.1", pid, remote_port,
+                                        socket_name))
    return false;

  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PLATFORM));
@@ -98,8 +100,9 @@ bool PlatformAndroidRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
 }

 bool PlatformAndroidRemoteGDBServer::KillSpawnedProcess(lldb::pid_t pid) {
+  assert(IsConnected());
  DeleteForwardPort(pid);
-  return m_gdb_client.KillSpawnedProcess(pid);
+  return m_gdb_client_up->KillSpawnedProcess(pid);
 }

 Status PlatformAndroidRemoteGDBServer::ConnectRemote(Args &args) {
--- a/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.cpp
+++ b/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.cpp
@@ -96,7 +96,8 @@ bool PlatformRemoteGDBServer::GetModuleSpec(const FileSpec &module_file_spec,

  const auto module_path = module_file_spec.GetPath(false);

-  if (!m_gdb_client.GetModuleInfo(module_file_spec, arch, module_spec)) {
+  if (!m_gdb_client_up ||
+      !m_gdb_client_up->GetModuleInfo(module_file_spec, arch, module_spec)) {
    LLDB_LOGF(
        log,
        "PlatformRemoteGDBServer::%s - failed to get module info for %s:%s",
@@ -127,11 +128,7 @@ Status PlatformRemoteGDBServer::GetFileWithUUID(const FileSpec &platform_file,

 /// Default Constructor
 PlatformRemoteGDBServer::PlatformRemoteGDBServer()
-    : Platform(false), // This is a remote platform
-      m_gdb_client() {
-  m_gdb_client.SetPacketTimeout(
-      process_gdb_remote::ProcessGDBRemote::GetPacketTimeout());
-}
+    : Platform(/*is_host=*/false) {}

 /// Destructor.
 ///
@@ -147,29 +144,36 @@ size_t PlatformRemoteGDBServer::GetSoftwareBreakpointTrapOpcode(
 }

 bool PlatformRemoteGDBServer::GetRemoteOSVersion() {
-  m_os_version = m_gdb_client.GetOSVersion();
+  if (m_gdb_client_up)
+    m_os_version = m_gdb_client_up->GetOSVersion();
  return !m_os_version.empty();
 }

 llvm::Optional<std::string> PlatformRemoteGDBServer::GetRemoteOSBuildString() {
-  return m_gdb_client.GetOSBuildString();
+  if (!m_gdb_client_up)
+    return llvm::None;
+  return m_gdb_client_up->GetOSBuildString();
 }

 llvm::Optional<std::string>
 PlatformRemoteGDBServer::GetRemoteOSKernelDescription() {
-  return m_gdb_client.GetOSKernelDescription();
+  if (!m_gdb_client_up)
+    return llvm::None;
+  return m_gdb_client_up->GetOSKernelDescription();
 }

 // Remote Platform subclasses need to override this function
 ArchSpec PlatformRemoteGDBServer::GetRemoteSystemArchitecture() {
-  return m_gdb_client.GetSystemArchitecture();
+  if (!m_gdb_client_up)
+    return ArchSpec();
+  return m_gdb_client_up->GetSystemArchitecture();
 }

 FileSpec PlatformRemoteGDBServer::GetRemoteWorkingDirectory() {
  if (IsConnected()) {
    Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
    FileSpec working_dir;
-    if (m_gdb_client.GetWorkingDir(working_dir) && log)
+    if (m_gdb_client_up->GetWorkingDir(working_dir) && log)
      LLDB_LOGF(log,
                "PlatformRemoteGDBServer::GetRemoteWorkingDirectory() -> '%s'",
                working_dir.GetCString());
@@ -187,13 +191,17 @@ bool PlatformRemoteGDBServer::SetRemoteWorkingDirectory(
    Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
    LLDB_LOGF(log, "PlatformRemoteGDBServer::SetRemoteWorkingDirectory('%s')",
              working_dir.GetCString());
-    return m_gdb_client.SetWorkingDir(working_dir) == 0;
+    return m_gdb_client_up->SetWorkingDir(working_dir) == 0;
  } else
    return Platform::SetRemoteWorkingDirectory(working_dir);
 }

 bool PlatformRemoteGDBServer::IsConnected() const {
-  return m_gdb_client.IsConnected();
+  if (m_gdb_client_up) {
+    assert(m_gdb_client_up->IsConnected());
+    return true;
+  }
+  return false;
 }

 Status PlatformRemoteGDBServer::ConnectRemote(Args &args) {
@@ -224,26 +232,31 @@ Status PlatformRemoteGDBServer::ConnectRemote(Args &args) {
  m_platform_scheme = parsed_url->scheme.str();
  m_platform_hostname = parsed_url->hostname.str();

-  m_gdb_client.SetConnection(std::make_unique<ConnectionFileDescriptor>());
+  auto client_up =
+      std::make_unique<process_gdb_remote::GDBRemoteCommunicationClient>();
+  client_up->SetPacketTimeout(
+      process_gdb_remote::ProcessGDBRemote::GetPacketTimeout());
+  client_up->SetConnection(std::make_unique<ConnectionFileDescriptor>());
  if (repro::Generator *g = repro::Reproducer::Instance().GetGenerator()) {
    repro::GDBRemoteProvider &provider =
        g->GetOrCreate<repro::GDBRemoteProvider>();
-    m_gdb_client.SetPacketRecorder(provider.GetNewPacketRecorder());
+    client_up->SetPacketRecorder(provider.GetNewPacketRecorder());
  }
-  m_gdb_client.Connect(url, &error);
+  client_up->Connect(url, &error);

  if (error.Fail())
    return error;

-  if (m_gdb_client.HandshakeWithServer(&error)) {
-    m_gdb_client.GetHostInfo();
+  if (client_up->HandshakeWithServer(&error)) {
+    m_gdb_client_up = std::move(client_up);
+    m_gdb_client_up->GetHostInfo();
    // If a working directory was set prior to connecting, send it down
    // now.
    if (m_working_dir)
-      m_gdb_client.SetWorkingDir(m_working_dir);
+      m_gdb_client_up->SetWorkingDir(m_working_dir);

    m_supported_architectures.clear();
-    ArchSpec remote_arch = m_gdb_client.GetSystemArchitecture();
+    ArchSpec remote_arch = m_gdb_client_up->GetSystemArchitecture();
    if (remote_arch) {
      m_supported_architectures.push_back(remote_arch);
      if (remote_arch.GetTriple().isArch64Bit())
@@ -251,7 +264,7 @@ Status PlatformRemoteGDBServer::ConnectRemote(Args &args) {
            ArchSpec(remote_arch.GetTriple().get32BitArchVariant()));
    }
  } else {
-    m_gdb_client.Disconnect();
+    client_up->Disconnect();
    if (error.Success())
      error.SetErrorString("handshake failed");
  }
@@ -260,13 +273,14 @@ Status PlatformRemoteGDBServer::ConnectRemote(Args &args) {

 Status PlatformRemoteGDBServer::DisconnectRemote() {
  Status error;
-  m_gdb_client.Disconnect(&error);
+  m_gdb_client_up.reset();
  m_remote_signals_sp.reset();
  return error;
 }

 const char *PlatformRemoteGDBServer::GetHostname() {
-  m_gdb_client.GetHostname(m_name);
+  if (m_gdb_client_up)
+    m_gdb_client_up->GetHostname(m_name);
  if (m_name.empty())
    return nullptr;
  return m_name.c_str();
@@ -275,7 +289,7 @@ const char *PlatformRemoteGDBServer::GetHostname() {
 llvm::Optional<std::string>
 PlatformRemoteGDBServer::DoGetUserName(UserIDResolver::id_t uid) {
  std::string name;
-  if (m_gdb_client.GetUserName(uid, name))
+  if (m_gdb_client_up && m_gdb_client_up->GetUserName(uid, name))
    return std::move(name);
  return llvm::None;
 }
@@ -283,7 +297,7 @@ PlatformRemoteGDBServer::DoGetUserName(UserIDResolver::id_t uid) {
 llvm::Optional<std::string>
 PlatformRemoteGDBServer::DoGetGroupName(UserIDResolver::id_t gid) {
  std::string name;
-  if (m_gdb_client.GetGroupName(gid, name))
+  if (m_gdb_client_up && m_gdb_client_up->GetGroupName(gid, name))
    return std::move(name);
  return llvm::None;
 }
@@ -291,12 +305,16 @@ PlatformRemoteGDBServer::DoGetGroupName(UserIDResolver::id_t gid) {
 uint32_t PlatformRemoteGDBServer::FindProcesses(
    const ProcessInstanceInfoMatch &match_info,
    ProcessInstanceInfoList &process_infos) {
-  return m_gdb_client.FindProcesses(match_info, process_infos);
+  if (m_gdb_client_up)
+    return m_gdb_client_up->FindProcesses(match_info, process_infos);
+  return 0;
 }

 bool PlatformRemoteGDBServer::GetProcessInfo(
    lldb::pid_t pid, ProcessInstanceInfo &process_info) {
-  return m_gdb_client.GetProcessInfo(pid, process_info);
+  if (m_gdb_client_up)
+    return m_gdb_client_up->GetProcessInfo(pid, process_info);
+  return false;
 }

 Status PlatformRemoteGDBServer::LaunchProcess(ProcessLaunchInfo &launch_info) {
@@ -305,6 +323,8 @@ Status PlatformRemoteGDBServer::LaunchProcess(ProcessLaunchInfo &launch_info) {

  LLDB_LOGF(log, "PlatformRemoteGDBServer::%s() called", __FUNCTION__);

+  if (!IsConnected())
+    return Status("Not connected.");
  auto num_file_actions = launch_info.GetNumFileActions();
  for (decltype(num_file_actions) i = 0; i < num_file_actions; ++i) {
    const auto file_action = launch_info.GetFileActionAtIndex(i);
@@ -312,34 +332,34 @@ Status PlatformRemoteGDBServer::LaunchProcess(ProcessLaunchInfo &launch_info) {
      continue;
    switch (file_action->GetFD()) {
    case STDIN_FILENO:
-      m_gdb_client.SetSTDIN(file_action->GetFileSpec());
+      m_gdb_client_up->SetSTDIN(file_action->GetFileSpec());
      break;
    case STDOUT_FILENO:
-      m_gdb_client.SetSTDOUT(file_action->GetFileSpec());
+      m_gdb_client_up->SetSTDOUT(file_action->GetFileSpec());
      break;
    case STDERR_FILENO:
-      m_gdb_client.SetSTDERR(file_action->GetFileSpec());
+      m_gdb_client_up->SetSTDERR(file_action->GetFileSpec());
      break;
    }
  }

-  m_gdb_client.SetDisableASLR(
+  m_gdb_client_up->SetDisableASLR(
      launch_info.GetFlags().Test(eLaunchFlagDisableASLR));
-  m_gdb_client.SetDetachOnError(
+  m_gdb_client_up->SetDetachOnError(
      launch_info.GetFlags().Test(eLaunchFlagDetachOnError));

  FileSpec working_dir = launch_info.GetWorkingDirectory();
  if (working_dir) {
-    m_gdb_client.SetWorkingDir(working_dir);
+    m_gdb_client_up->SetWorkingDir(working_dir);
  }

  // Send the environment and the program + arguments after we connect
-  m_gdb_client.SendEnvironment(launch_info.GetEnvironment());
+  m_gdb_client_up->SendEnvironment(launch_info.GetEnvironment());

  ArchSpec arch_spec = launch_info.GetArchitecture();
  const char *arch_triple = arch_spec.GetTriple().str().c_str();

-  m_gdb_client.SendLaunchArchPacket(arch_triple);
+  m_gdb_client_up->SendLaunchArchPacket(arch_triple);
  LLDB_LOGF(
      log,
      "PlatformRemoteGDBServer::%s() set launch architecture triple to '%s'",
@@ -349,14 +369,14 @@ Status PlatformRemoteGDBServer::LaunchProcess(ProcessLaunchInfo &launch_info) {
  {
    // Scope for the scoped timeout object
    process_gdb_remote::GDBRemoteCommunication::ScopedTimeout timeout(
-        m_gdb_client, std::chrono::seconds(5));
-    arg_packet_err = m_gdb_client.SendArgumentsPacket(launch_info);
+        *m_gdb_client_up, std::chrono::seconds(5));
+    arg_packet_err = m_gdb_client_up->SendArgumentsPacket(launch_info);
  }

  if (arg_packet_err == 0) {
    std::string error_str;
-    if (m_gdb_client.GetLaunchSuccess(error_str)) {
-      const auto pid = m_gdb_client.GetCurrentProcessID(false);
+    if (m_gdb_client_up->GetLaunchSuccess(error_str)) {
+      const auto pid = m_gdb_client_up->GetCurrentProcessID(false);
      if (pid != LLDB_INVALID_PROCESS_ID) {
        launch_info.SetProcessID(pid);
        LLDB_LOGF(log,
@@ -428,6 +448,8 @@ PlatformRemoteGDBServer::DebugProcess(ProcessLaunchInfo &launch_info,

 bool PlatformRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
                                              std::string &connect_url) {
+  assert(IsConnected());
+
  ArchSpec remote_arch = GetRemoteSystemArchitecture();
  llvm::Triple &remote_triple = remote_arch.GetTriple();

@@ -440,11 +462,11 @@ bool PlatformRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
    // localhost, so we will need the remote debugserver to accept connections
    // only from localhost, no matter what our current hostname is
    launch_result =
-        m_gdb_client.LaunchGDBServer("127.0.0.1", pid, port, socket_name);
+        m_gdb_client_up->LaunchGDBServer("127.0.0.1", pid, port, socket_name);
  } else {
    // All other hosts should use their actual hostname
    launch_result =
-        m_gdb_client.LaunchGDBServer(nullptr, pid, port, socket_name);
+        m_gdb_client_up->LaunchGDBServer(nullptr, pid, port, socket_name);
  }

  if (!launch_result)
@@ -457,7 +479,8 @@ bool PlatformRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
 }

 bool PlatformRemoteGDBServer::KillSpawnedProcess(lldb::pid_t pid) {
-  return m_gdb_client.KillSpawnedProcess(pid);
+  assert(IsConnected());
+  return m_gdb_client_up->KillSpawnedProcess(pid);
 }

 lldb::ProcessSP PlatformRemoteGDBServer::Attach(
@@ -513,7 +536,9 @@ lldb::ProcessSP PlatformRemoteGDBServer::Attach(

 Status PlatformRemoteGDBServer::MakeDirectory(const FileSpec &file_spec,
                                              uint32_t mode) {
-  Status error = m_gdb_client.MakeDirectory(file_spec, mode);
+  if (!IsConnected())
+    return Status("Not connected.");
+  Status error = m_gdb_client_up->MakeDirectory(file_spec, mode);
  Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
  LLDB_LOGF(log,
            "PlatformRemoteGDBServer::MakeDirectory(path='%s', mode=%o) "
@@ -524,7 +549,10 @@ Status PlatformRemoteGDBServer::MakeDirectory(const FileSpec &file_spec,

 Status PlatformRemoteGDBServer::GetFilePermissions(const FileSpec &file_spec,
                                                   uint32_t &file_permissions) {
-  Status error = m_gdb_client.GetFilePermissions(file_spec, file_permissions);
+  if (!IsConnected())
+    return Status("Not connected.");
+  Status error =
+      m_gdb_client_up->GetFilePermissions(file_spec, file_permissions);
  Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
  LLDB_LOGF(log,
            "PlatformRemoteGDBServer::GetFilePermissions(path='%s', "
@@ -536,7 +564,10 @@ Status PlatformRemoteGDBServer::GetFilePermissions(const FileSpec &file_spec,

 Status PlatformRemoteGDBServer::SetFilePermissions(const FileSpec &file_spec,
                                                   uint32_t file_permissions) {
-  Status error = m_gdb_client.SetFilePermissions(file_spec, file_permissions);
+  if (!IsConnected())
+    return Status("Not connected.");
+  Status error =
+      m_gdb_client_up->SetFilePermissions(file_spec, file_permissions);
  Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
  LLDB_LOGF(log,
            "PlatformRemoteGDBServer::SetFilePermissions(path='%s', "
@@ -550,33 +581,47 @@ lldb::user_id_t PlatformRemoteGDBServer::OpenFile(const FileSpec &file_spec,
                                                  File::OpenOptions flags,
                                                  uint32_t mode,
                                                  Status &error) {
-  return m_gdb_client.OpenFile(file_spec, flags, mode, error);
+  if (IsConnected())
+    return m_gdb_client_up->OpenFile(file_spec, flags, mode, error);
+  return LLDB_INVALID_UID;
 }

 bool PlatformRemoteGDBServer::CloseFile(lldb::user_id_t fd, Status &error) {
-  return m_gdb_client.CloseFile(fd, error);
+  if (IsConnected())
+    return m_gdb_client_up->CloseFile(fd, error);
+  error = Status("Not connected.");
+  return false;
 }

 lldb::user_id_t
 PlatformRemoteGDBServer::GetFileSize(const FileSpec &file_spec) {
-  return m_gdb_client.GetFileSize(file_spec);
+  if (IsConnected())
+    return m_gdb_client_up->GetFileSize(file_spec);
+  return LLDB_INVALID_UID;
 }

 void PlatformRemoteGDBServer::AutoCompleteDiskFileOrDirectory(
    CompletionRequest &request, bool only_dir) {
-  m_gdb_client.AutoCompleteDiskFileOrDirectory(request, only_dir);
+  if (IsConnected())
+    m_gdb_client_up->AutoCompleteDiskFileOrDirectory(request, only_dir);
 }

 uint64_t PlatformRemoteGDBServer::ReadFile(lldb::user_id_t fd, uint64_t offset,
                                           void *dst, uint64_t dst_len,
                                           Status &error) {
-  return m_gdb_client.ReadFile(fd, offset, dst, dst_len, error);
+  if (IsConnected())
+    return m_gdb_client_up->ReadFile(fd, offset, dst, dst_len, error);
+  error = Status("Not connected.");
+  return 0;
 }

 uint64_t PlatformRemoteGDBServer::WriteFile(lldb::user_id_t fd, uint64_t offset,
                                            const void *src, uint64_t src_len,
                                            Status &error) {
-  return m_gdb_client.WriteFile(fd, offset, src, src_len, error);
+  if (IsConnected())
+    return m_gdb_client_up->WriteFile(fd, offset, src, src_len, error);
+  error = Status("Not connected.");
+  return 0;
 }

 Status PlatformRemoteGDBServer::PutFile(const FileSpec &source,
@@ -589,7 +634,9 @@ Status PlatformRemoteGDBServer::CreateSymlink(
    const FileSpec &src, // The name of the link is in src
    const FileSpec &dst) // The symlink points to dst
 {
-  Status error = m_gdb_client.CreateSymlink(src, dst);
+  if (!IsConnected())
+    return Status("Not connected.");
+  Status error = m_gdb_client_up->CreateSymlink(src, dst);
  Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
  LLDB_LOGF(log,
            "PlatformRemoteGDBServer::CreateSymlink(src='%s', dst='%s') "
@@ -600,7 +647,9 @@ Status PlatformRemoteGDBServer::CreateSymlink(
 }

 Status PlatformRemoteGDBServer::Unlink(const FileSpec &file_spec) {
-  Status error = m_gdb_client.Unlink(file_spec);
+  if (!IsConnected())
+    return Status("Not connected.");
+  Status error = m_gdb_client_up->Unlink(file_spec);
  Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM);
  LLDB_LOGF(log, "PlatformRemoteGDBServer::Unlink(path='%s') error = %u (%s)",
            file_spec.GetCString(), error.GetError(), error.AsCString());
@@ -608,7 +657,9 @@ Status PlatformRemoteGDBServer::Unlink(const FileSpec &file_spec) {
 }

 bool PlatformRemoteGDBServer::GetFileExists(const FileSpec &file_spec) {
-  return m_gdb_client.GetFileExists(file_spec);
+  if (IsConnected())
+    return m_gdb_client_up->GetFileExists(file_spec);
+  return false;
 }

 Status PlatformRemoteGDBServer::RunShellCommand(
@@ -621,8 +672,10 @@ Status PlatformRemoteGDBServer::RunShellCommand(
    std::string
        *command_output, // Pass NULL if you don't want the command output
    const Timeout<std::micro> &timeout) {
-  return m_gdb_client.RunShellCommand(command, working_dir, status_ptr,
-                                      signo_ptr, command_output, timeout);
+  if (!IsConnected())
+    return Status("Not connected.");
+  return m_gdb_client_up->RunShellCommand(command, working_dir, status_ptr,
+                                          signo_ptr, command_output, timeout);
 }

 void PlatformRemoteGDBServer::CalculateTrapHandlerSymbolNames() {
@@ -642,7 +695,7 @@ const UnixSignalsSP &PlatformRemoteGDBServer::GetRemoteUnixSignals() {

  StringExtractorGDBRemote response;
  auto result =
-      m_gdb_client.SendPacketAndWaitForResponse("jSignalsInfo", response);
+      m_gdb_client_up->SendPacketAndWaitForResponse("jSignalsInfo", response);

  if (result != decltype(result)::Success ||
      response.GetResponseType() != response.eResponse)
@@ -754,7 +807,9 @@ size_t PlatformRemoteGDBServer::ConnectToWaitingProcesses(Debugger &debugger,
 size_t PlatformRemoteGDBServer::GetPendingGdbServerList(
    std::vector<std::string> &connection_urls) {
  std::vector<std::pair<uint16_t, std::string>> remote_servers;
-  m_gdb_client.QueryGDBServer(remote_servers);
+  if (!IsConnected())
+    return 0;
+  m_gdb_client_up->QueryGDBServer(remote_servers);
  for (const auto &gdbserver : remote_servers) {
    const char *socket_name_cstr =
        gdbserver.second.empty() ? nullptr : gdbserver.second.c_str();
--- a/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h
+++ b/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h
@@ -153,7 +153,8 @@ public:
  GetPendingGdbServerList(std::vector<std::string> &connection_urls);

 protected:
-  process_gdb_remote::GDBRemoteCommunicationClient m_gdb_client;
+  std::unique_ptr<process_gdb_remote::GDBRemoteCommunicationClient>
+      m_gdb_client_up;
  std::string m_platform_description; // After we connect we can get a more
                                      // complete description of what we are
                                      // connected to
--- a/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemotePlatformFile.py
+++ b/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemotePlatformFile.py
@@ -107,6 +107,25 @@ class TestGDBRemotePlatformFile(GDBPlatformClientTestBase):
            "vFile:close:5",
            ])

+        self.runCmd("platform disconnect")
+
+        # For a new onnection, we should attempt vFile:size once again.
+        server2 = MockGDBServer(self.server_socket_class())
+        server2.responder = Responder()
+        server2.start()
+        self.addTearDownHook(lambda:server2.stop())
+        self.runCmd("platform connect " + server2.get_connect_url())
+        self.match("platform get-size /other/file.txt",
+                   [r"File size of /other/file\.txt \(remote\): 66051"])
+
+        self.assertPacketLogContains([
+            "vFile:size:2f6f746865722f66696c652e747874",
+            "vFile:open:2f6f746865722f66696c652e747874,00000000,00000000",
+            "vFile:fstat:5",
+            "vFile:close:5",
+            ],
+            log=server2.responder.packetLog)
+
    @skipIfWindows
    def test_file_permissions(self):
        """Test 'platform get-permissions'"""