[Lldb-commits] [lldb] 82ee31f - [lldb] Updated lldb-server to spawn the child process and share socket (#101283)
via lldb-commits
lldb-commits at lists.llvm.org
Mon Aug 12 07:50:27 PDT 2024
Author: Dmitry Vasilyev
Date: 2024-08-12T18:50:23+04:00
New Revision: 82ee31f75ac1316006fa9e21dddfddec37cf7072
URL: https://github.com/llvm/llvm-project/commit/82ee31f75ac1316006fa9e21dddfddec37cf7072
DIFF: https://github.com/llvm/llvm-project/commit/82ee31f75ac1316006fa9e21dddfddec37cf7072.diff
LOG: [lldb] Updated lldb-server to spawn the child process and share socket (#101283)
`lldb-server platform --server` works on Windows now w/o multithreading.
The rest functionality remains unchanged.
Fixes #90923, fixes #56346.
This is the part 1 of the replacement of #100670.
In the part 2 I plan to switch `lldb-server gdbserver` to use `--fd` and
listen a common gdb port for all gdbserver connections. Then we can
remove gdb port mapping to fiŃ… #97537.
Added:
Modified:
lldb/tools/lldb-server/lldb-platform.cpp
Removed:
################################################################################
diff --git a/lldb/tools/lldb-server/lldb-platform.cpp b/lldb/tools/lldb-server/lldb-platform.cpp
index 7148a1d2a30941..82a3a0d6b4e51c 100644
--- a/lldb/tools/lldb-server/lldb-platform.cpp
+++ b/lldb/tools/lldb-server/lldb-platform.cpp
@@ -22,6 +22,7 @@
#include <optional>
#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
@@ -32,8 +33,10 @@
#include "lldb/Host/ConnectionFileDescriptor.h"
#include "lldb/Host/HostGetOpt.h"
#include "lldb/Host/OptionParser.h"
+#include "lldb/Host/Socket.h"
#include "lldb/Host/common/TCPSocket.h"
#include "lldb/Utility/FileSpec.h"
+#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Status.h"
using namespace lldb;
@@ -44,6 +47,108 @@ using namespace llvm;
// option descriptors for getopt_long_only()
+#ifdef _WIN32
+typedef pipe_t shared_fd_t;
+const shared_fd_t kInvalidSharedFD = LLDB_INVALID_PIPE;
+#else
+typedef NativeSocket shared_fd_t;
+const shared_fd_t kInvalidSharedFD = Socket::kInvalidSocketValue;
+#endif
+
+class SharedSocket {
+public:
+ SharedSocket(Connection *conn, Status &error) {
+ m_fd = kInvalidSharedFD;
+
+ const Socket *socket =
+ static_cast<const Socket *>(conn->GetReadObject().get());
+ if (socket == nullptr) {
+ error = Status("invalid conn socket");
+ return;
+ }
+
+#ifdef _WIN32
+ m_socket = socket->GetNativeSocket();
+
+ // Create a pipe to transfer WSAPROTOCOL_INFO to the child process.
+ error = m_socket_pipe.CreateNew(true);
+ if (error.Fail())
+ return;
+
+ m_fd = m_socket_pipe.GetReadPipe();
+#else
+ m_fd = socket->GetNativeSocket();
+ error = Status();
+#endif
+ }
+
+ shared_fd_t GetSendableFD() { return m_fd; }
+
+ Status CompleteSending(lldb::pid_t child_pid) {
+#ifdef _WIN32
+ // Transfer WSAPROTOCOL_INFO to the child process.
+ m_socket_pipe.CloseReadFileDescriptor();
+
+ WSAPROTOCOL_INFO protocol_info;
+ if (::WSADuplicateSocket(m_socket, child_pid, &protocol_info) ==
+ SOCKET_ERROR) {
+ int last_error = ::WSAGetLastError();
+ return Status("WSADuplicateSocket() failed, error: %d", last_error);
+ }
+
+ size_t num_bytes;
+ Status error =
+ m_socket_pipe.WriteWithTimeout(&protocol_info, sizeof(protocol_info),
+ std::chrono::seconds(10), num_bytes);
+ if (error.Fail())
+ return error;
+ if (num_bytes != sizeof(protocol_info))
+ return Status("WriteWithTimeout(WSAPROTOCOL_INFO) failed: %d bytes",
+ num_bytes);
+#endif
+ return Status();
+ }
+
+ static Status GetNativeSocket(shared_fd_t fd, NativeSocket &socket) {
+#ifdef _WIN32
+ socket = Socket::kInvalidSocketValue;
+ // Read WSAPROTOCOL_INFO from the parent process and create NativeSocket.
+ WSAPROTOCOL_INFO protocol_info;
+ {
+ Pipe socket_pipe(fd, LLDB_INVALID_PIPE);
+ size_t num_bytes;
+ Status error =
+ socket_pipe.ReadWithTimeout(&protocol_info, sizeof(protocol_info),
+ std::chrono::seconds(10), num_bytes);
+ if (error.Fail())
+ return error;
+ if (num_bytes != sizeof(protocol_info)) {
+ return Status(
+ "socket_pipe.ReadWithTimeout(WSAPROTOCOL_INFO) failed: % d bytes",
+ num_bytes);
+ }
+ }
+ socket = ::WSASocket(FROM_PROTOCOL_INFO, FROM_PROTOCOL_INFO,
+ FROM_PROTOCOL_INFO, &protocol_info, 0, 0);
+ if (socket == INVALID_SOCKET) {
+ return Status("WSASocket(FROM_PROTOCOL_INFO) failed: error %d",
+ ::WSAGetLastError());
+ }
+ return Status();
+#else
+ socket = fd;
+ return Status();
+#endif
+ }
+
+private:
+#ifdef _WIN32
+ Pipe m_socket_pipe;
+ NativeSocket m_socket;
+#endif
+ shared_fd_t m_fd;
+};
+
static int g_debug = 0;
static int g_verbose = 0;
static int g_server = 0;
@@ -60,6 +165,7 @@ static struct option g_long_options[] = {
{"max-gdbserver-port", required_argument, nullptr, 'M'},
{"socket-file", required_argument, nullptr, 'f'},
{"server", no_argument, &g_server, 1},
+ {"child-platform-fd", required_argument, nullptr, 2},
{nullptr, 0, nullptr, 0}};
#if defined(__APPLE__)
@@ -114,6 +220,130 @@ static Status save_socket_id_to_file(const std::string &socket_id,
return status;
}
+static void client_handle(GDBRemoteCommunicationServerPlatform &platform,
+ const lldb_private::Args &args) {
+ if (!platform.IsConnected())
+ return;
+
+ if (args.GetArgumentCount() > 0) {
+ lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
+ std::optional<uint16_t> port;
+ std::string socket_name;
+ Status error = platform.LaunchGDBServer(args,
+ "", // hostname
+ pid, port, socket_name);
+ if (error.Success())
+ platform.SetPendingGdbServer(pid, *port, socket_name);
+ else
+ fprintf(stderr, "failed to start gdbserver: %s\n", error.AsCString());
+ }
+
+ bool interrupt = false;
+ bool done = false;
+ Status error;
+ while (!interrupt && !done) {
+ if (platform.GetPacketAndSendResponse(std::nullopt, error, interrupt,
+ done) !=
+ GDBRemoteCommunication::PacketResult::Success)
+ break;
+ }
+
+ printf("Disconnected.\n");
+}
+
+static GDBRemoteCommunicationServerPlatform::PortMap gdbserver_portmap;
+static std::mutex gdbserver_portmap_mutex;
+
+static void spawn_process_reaped(lldb::pid_t pid, int signal, int status) {
+ std::lock_guard<std::mutex> guard(gdbserver_portmap_mutex);
+ gdbserver_portmap.FreePortForProcess(pid);
+}
+
+static Status spawn_process(const char *progname, Connection *conn,
+ uint16_t gdb_port, uint16_t port_offset,
+ const lldb_private::Args &args,
+ const std::string &log_file,
+ const StringRef log_channels) {
+ Status error;
+ SharedSocket shared_socket(conn, error);
+ if (error.Fail())
+ return error;
+
+ ProcessLaunchInfo launch_info;
+
+ FileSpec self_spec(progname, FileSpec::Style::native);
+ launch_info.SetExecutableFile(self_spec, true);
+ Args &self_args = launch_info.GetArguments();
+ self_args.AppendArgument(llvm::StringRef("platform"));
+ self_args.AppendArgument(llvm::StringRef("--child-platform-fd"));
+ self_args.AppendArgument(llvm::to_string(shared_socket.GetSendableFD()));
+ if (gdb_port) {
+ self_args.AppendArgument(llvm::StringRef("--gdbserver-port"));
+ self_args.AppendArgument(llvm::to_string(gdb_port));
+ }
+ if (port_offset > 0) {
+ self_args.AppendArgument(llvm::StringRef("--port-offset"));
+ self_args.AppendArgument(llvm::to_string(port_offset));
+ }
+ if (!log_file.empty()) {
+ self_args.AppendArgument(llvm::StringRef("--log-file"));
+ self_args.AppendArgument(log_file);
+ }
+ if (!log_channels.empty()) {
+ self_args.AppendArgument(llvm::StringRef("--log-channels"));
+ self_args.AppendArgument(log_channels);
+ }
+ if (args.GetArgumentCount() > 0) {
+ self_args.AppendArgument("--");
+ self_args.AppendArguments(args);
+ }
+
+ launch_info.SetLaunchInSeparateProcessGroup(false);
+ launch_info.SetMonitorProcessCallback(&spawn_process_reaped);
+
+ // Copy the current environment.
+ launch_info.GetEnvironment() = Host::GetEnvironment();
+
+ launch_info.GetFlags().Set(eLaunchFlagDisableSTDIO);
+
+ // Close STDIN, STDOUT and STDERR.
+ launch_info.AppendCloseFileAction(STDIN_FILENO);
+ launch_info.AppendCloseFileAction(STDOUT_FILENO);
+ launch_info.AppendCloseFileAction(STDERR_FILENO);
+
+ // Redirect STDIN, STDOUT and STDERR to "/dev/null".
+ launch_info.AppendSuppressFileAction(STDIN_FILENO, true, false);
+ launch_info.AppendSuppressFileAction(STDOUT_FILENO, false, true);
+ launch_info.AppendSuppressFileAction(STDERR_FILENO, false, true);
+
+ std::string cmd;
+ self_args.GetCommandString(cmd);
+
+ error = Host::LaunchProcess(launch_info);
+ if (error.Fail())
+ return error;
+
+ lldb::pid_t child_pid = launch_info.GetProcessID();
+ if (child_pid == LLDB_INVALID_PROCESS_ID)
+ return Status("invalid pid");
+
+ LLDB_LOG(GetLog(LLDBLog::Platform), "lldb-platform launched '{0}', pid={1}",
+ cmd, child_pid);
+
+ {
+ std::lock_guard<std::mutex> guard(gdbserver_portmap_mutex);
+ gdbserver_portmap.AssociatePortWithProcess(gdb_port, child_pid);
+ }
+
+ error = shared_socket.CompleteSending(child_pid);
+ if (error.Fail()) {
+ Host::Kill(child_pid, SIGTERM);
+ return error;
+ }
+
+ return Status();
+}
+
// main
int main_platform(int argc, char *argv[]) {
const char *progname = argv[0];
@@ -133,7 +363,8 @@ int main_platform(int argc, char *argv[]) {
StringRef
log_channels; // e.g. "lldb process threads:gdb-remote default:linux all"
- GDBRemoteCommunicationServerPlatform::PortMap gdbserver_portmap;
+ shared_fd_t fd = kInvalidSharedFD;
+
int min_gdbserver_port = 0;
int max_gdbserver_port = 0;
uint16_t port_offset = 0;
@@ -217,6 +448,15 @@ int main_platform(int argc, char *argv[]) {
max_gdbserver_port = portnum;
} break;
+ case 2: {
+ uint64_t _fd;
+ if (!llvm::to_integer(optarg, _fd)) {
+ WithColor::error() << "invalid fd " << optarg << "\n";
+ option_error = 6;
+ } else
+ fd = (shared_fd_t)_fd;
+ } break;
+
case 'h': /* fall-through is intentional */
case '?':
show_usage = true;
@@ -240,7 +480,7 @@ int main_platform(int argc, char *argv[]) {
}
// Print usage and exit if no listening port is specified.
- if (listen_host_port.empty())
+ if (listen_host_port.empty() && fd == kInvalidSharedFD)
show_usage = true;
if (show_usage || option_error) {
@@ -254,6 +494,33 @@ int main_platform(int argc, char *argv[]) {
lldb_private::Args inferior_arguments;
inferior_arguments.SetArguments(argc, const_cast<const char **>(argv));
+ if (fd != kInvalidSharedFD) {
+ // Child process will handle the connection and exit.
+ Log *log = GetLog(LLDBLog::Platform);
+ if (!listen_host_port.empty()) {
+ LLDB_LOGF(log, "lldb-platform child: "
+ "ambiguous parameters --listen and --child-platform-fd");
+ return socket_error;
+ }
+
+ NativeSocket socket;
+ error = SharedSocket::GetNativeSocket(fd, socket);
+ if (error.Fail()) {
+ LLDB_LOGF(log, "lldb-platform child: %s", error.AsCString());
+ return socket_error;
+ }
+
+ Connection *conn =
+ new ConnectionFileDescriptor(new TCPSocket(socket, true, false));
+ GDBRemoteCommunicationServerPlatform platform(Socket::ProtocolTcp, "tcp");
+ if (port_offset > 0)
+ platform.SetPortOffset(port_offset);
+ platform.SetPortMap(std::move(gdbserver_portmap));
+ platform.SetConnection(std::unique_ptr<Connection>(conn));
+ client_handle(platform, inferior_arguments);
+ return 0;
+ }
+
const bool children_inherit_listen_socket = false;
// the test suite makes many connections in parallel, let's not miss any.
// The highest this should get reasonably is a function of the number
@@ -298,48 +565,38 @@ int main_platform(int argc, char *argv[]) {
printf("Connection established.\n");
if (g_server) {
- // Collect child zombie processes.
-#if !defined(_WIN32)
- ::pid_t waitResult;
- while ((waitResult = waitpid(-1, nullptr, WNOHANG)) > 0) {
- // waitResult is the child pid
- gdbserver_portmap.FreePortForProcess(waitResult);
+ std::optional<uint16_t> available_port;
+ {
+ std::lock_guard<std::mutex> guard(gdbserver_portmap_mutex);
+ auto port = gdbserver_portmap.GetNextAvailablePort();
+ if (port)
+ available_port = *port;
+ else
+ llvm::consumeError(port.takeError());
}
-#endif
- // TODO: Clean up portmap for Windows when children die
- // See https://github.com/llvm/llvm-project/issues/90923
-
- // After collecting zombie ports, get the next available
- GDBRemoteCommunicationServerPlatform::PortMap portmap_for_child;
- llvm::Expected<uint16_t> available_port =
- gdbserver_portmap.GetNextAvailablePort();
- if (available_port) {
- // GetNextAvailablePort() may return 0 if gdbserver_portmap is empty.
- if (*available_port)
- portmap_for_child.AllowPort(*available_port);
- } else {
- llvm::consumeError(available_port.takeError());
+ if (!available_port) {
fprintf(stderr,
"no available gdbserver port for connection - dropping...\n");
- delete conn;
- continue;
- }
- platform.SetPortMap(std::move(portmap_for_child));
-
- auto childPid = fork();
- if (childPid) {
- gdbserver_portmap.AssociatePortWithProcess(*available_port, childPid);
- // Parent doesn't need a connection to the lldb client
- delete conn;
-
- // Parent will continue to listen for new connections.
- continue;
} else {
- // Child process will handle the connection and exit.
- g_server = 0;
- // Listening socket is owned by parent process.
- acceptor_up.release();
+ error = spawn_process(progname, conn, *available_port, port_offset,
+ inferior_arguments, log_file, log_channels);
+ if (error.Fail()) {
+ {
+
+ std::lock_guard<std::mutex> guard(gdbserver_portmap_mutex);
+ gdbserver_portmap.FreePort(*available_port);
+ }
+ LLDB_LOGF(GetLog(LLDBLog::Platform), "spawn_process failed: %s",
+ error.AsCString());
+ WithColor::error()
+ << "spawn_process failed: " << error.AsCString() << "\n";
+ }
}
+ // Parent doesn't need a connection to the lldb client
+ delete conn;
+
+ // Parent will continue to listen for new connections.
+ continue;
} else {
// If not running as a server, this process will not accept
// connections while a connection is active.
@@ -350,33 +607,7 @@ int main_platform(int argc, char *argv[]) {
}
platform.SetConnection(std::unique_ptr<Connection>(conn));
-
- if (platform.IsConnected()) {
- if (inferior_arguments.GetArgumentCount() > 0) {
- lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
- std::optional<uint16_t> port;
- std::string socket_name;
- Status error = platform.LaunchGDBServer(inferior_arguments,
- "", // hostname
- pid, port, socket_name);
- if (error.Success())
- platform.SetPendingGdbServer(pid, *port, socket_name);
- else
- fprintf(stderr, "failed to start gdbserver: %s\n", error.AsCString());
- }
-
- bool interrupt = false;
- bool done = false;
- while (!interrupt && !done) {
- if (platform.GetPacketAndSendResponse(std::nullopt, error, interrupt,
- done) !=
- GDBRemoteCommunication::PacketResult::Success)
- break;
- }
-
- if (error.Fail())
- WithColor::error() << error.AsCString() << '\n';
- }
+ client_handle(platform, inferior_arguments);
} while (g_server);
fprintf(stderr, "lldb-server exiting...\n");
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