llvm-project/lldb/tools/lldb-server/lldb-gdbserver.cpp

595 lines
20 KiB
C++

//===-- lldb-gdbserver.cpp --------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32
#include <signal.h>
#include <unistd.h>
#endif
// C++ Includes
// Other libraries and framework includes
#include "llvm/ADT/StringRef.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Host/ConnectionFileDescriptor.h"
#include "lldb/Host/HostGetOpt.h"
#include "lldb/Host/OptionParser.h"
#include "lldb/Host/Pipe.h"
#include "lldb/Host/Socket.h"
#include "lldb/Host/StringConvert.h"
#include "lldb/Target/Platform.h"
#include "Acceptor.h"
#include "LLDBServerUtilities.h"
#include "Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h"
#include "Plugins/Process/gdb-remote/ProcessGDBRemoteLog.h"
#ifndef LLGS_PROGRAM_NAME
#define LLGS_PROGRAM_NAME "lldb-server"
#endif
#ifndef LLGS_VERSION_STR
#define LLGS_VERSION_STR "local_build"
#endif
using namespace llvm;
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::lldb_server;
using namespace lldb_private::process_gdb_remote;
//----------------------------------------------------------------------
// option descriptors for getopt_long_only()
//----------------------------------------------------------------------
static int g_debug = 0;
static int g_verbose = 0;
static struct option g_long_options[] =
{
{ "debug", no_argument, &g_debug, 1 },
{ "platform", required_argument, NULL, 'p' },
{ "verbose", no_argument, &g_verbose, 1 },
{ "log-file", required_argument, NULL, 'l' },
{ "log-channels", required_argument, NULL, 'c' },
{ "attach", required_argument, NULL, 'a' },
{ "named-pipe", required_argument, NULL, 'N' },
{ "pipe", required_argument, NULL, 'U' },
{ "native-regs", no_argument, NULL, 'r' }, // Specify to use the native registers instead of the gdb defaults for the architecture. NOTE: this is a do-nothing arg as it's behavior is default now. FIXME remove call from lldb-platform.
{ "reverse-connect", no_argument, NULL, 'R' }, // Specifies that llgs attaches to the client address:port rather than llgs listening for a connection from address on port.
{ "setsid", no_argument, NULL, 'S' }, // Call setsid() to make llgs run in its own session.
{ NULL, 0, NULL, 0 }
};
//----------------------------------------------------------------------
// Watch for signals
//----------------------------------------------------------------------
static int g_sigpipe_received = 0;
static int g_sighup_received_count = 0;
#ifndef _WIN32
static void
signal_handler(int signo)
{
Log *log (GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
fprintf (stderr, "lldb-server:%s received signal %d\n", __FUNCTION__, signo);
if (log)
log->Printf ("lldb-server:%s received signal %d", __FUNCTION__, signo);
switch (signo)
{
case SIGPIPE:
g_sigpipe_received = 1;
break;
}
}
static void
sighup_handler(MainLoopBase &mainloop)
{
++g_sighup_received_count;
Log *log (GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
if (log)
log->Printf ("lldb-server:%s swallowing SIGHUP (receive count=%d)", __FUNCTION__, g_sighup_received_count);
if (g_sighup_received_count >= 2)
mainloop.RequestTermination();
}
#endif // #ifndef _WIN32
static void
display_usage (const char *progname, const char* subcommand)
{
fprintf(stderr, "Usage:\n %s %s "
"[--log-file log-file-name] "
"[--log-channels log-channel-list] "
"[--platform platform_name] "
"[--setsid] "
"[--named-pipe named-pipe-path] "
"[--native-regs] "
"[--attach pid] "
"[[HOST]:PORT] "
"[-- PROGRAM ARG1 ARG2 ...]\n", progname, subcommand);
exit(0);
}
static void
dump_available_platforms (FILE *output_file)
{
fprintf (output_file, "Available platform plugins:\n");
for (int i = 0; ; ++i)
{
const char *plugin_name = PluginManager::GetPlatformPluginNameAtIndex (i);
const char *plugin_desc = PluginManager::GetPlatformPluginDescriptionAtIndex (i);
if (!plugin_name || !plugin_desc)
break;
fprintf (output_file, "%s\t%s\n", plugin_name, plugin_desc);
}
if ( Platform::GetHostPlatform () )
{
// add this since the default platform doesn't necessarily get registered by
// the plugin name (e.g. 'host' doesn't show up as a
// registered platform plugin even though it's the default).
fprintf (output_file, "%s\tDefault platform for this host.\n", Platform::GetHostPlatform ()->GetPluginName ().AsCString ());
}
}
static lldb::PlatformSP
setup_platform (const std::string &platform_name)
{
lldb::PlatformSP platform_sp;
if (platform_name.empty())
{
printf ("using the default platform: ");
platform_sp = Platform::GetHostPlatform ();
printf ("%s\n", platform_sp->GetPluginName ().AsCString ());
return platform_sp;
}
Error error;
platform_sp = Platform::Create (lldb_private::ConstString(platform_name), error);
if (error.Fail ())
{
// the host platform isn't registered with that name (at
// least, not always. Check if the given name matches
// the default platform name. If so, use it.
if ( Platform::GetHostPlatform () && ( Platform::GetHostPlatform ()->GetPluginName () == ConstString (platform_name.c_str()) ) )
{
platform_sp = Platform::GetHostPlatform ();
}
else
{
fprintf (stderr, "error: failed to create platform with name '%s'\n", platform_name.c_str());
dump_available_platforms (stderr);
exit (1);
}
}
printf ("using platform: %s\n", platform_name.c_str ());
return platform_sp;
}
void
handle_attach_to_pid (GDBRemoteCommunicationServerLLGS &gdb_server, lldb::pid_t pid)
{
Error error = gdb_server.AttachToProcess (pid);
if (error.Fail ())
{
fprintf (stderr, "error: failed to attach to pid %" PRIu64 ": %s\n", pid, error.AsCString());
exit(1);
}
}
void
handle_attach_to_process_name (GDBRemoteCommunicationServerLLGS &gdb_server, const std::string &process_name)
{
// FIXME implement.
}
void
handle_attach (GDBRemoteCommunicationServerLLGS &gdb_server, const std::string &attach_target)
{
assert (!attach_target.empty () && "attach_target cannot be empty");
// First check if the attach_target is convertible to a long. If so, we'll use it as a pid.
char *end_p = nullptr;
const long int pid = strtol (attach_target.c_str (), &end_p, 10);
// We'll call it a match if the entire argument is consumed.
if (end_p && static_cast<size_t> (end_p - attach_target.c_str ()) == attach_target.size ())
handle_attach_to_pid (gdb_server, static_cast<lldb::pid_t> (pid));
else
handle_attach_to_process_name (gdb_server, attach_target);
}
void
handle_launch (GDBRemoteCommunicationServerLLGS &gdb_server, int argc, const char *const argv[])
{
Error error;
error = gdb_server.SetLaunchArguments (argv, argc);
if (error.Fail ())
{
fprintf (stderr, "error: failed to set launch args for '%s': %s\n", argv[0], error.AsCString());
exit(1);
}
unsigned int launch_flags = eLaunchFlagStopAtEntry | eLaunchFlagDebug;
error = gdb_server.SetLaunchFlags (launch_flags);
if (error.Fail ())
{
fprintf (stderr, "error: failed to set launch flags for '%s': %s\n", argv[0], error.AsCString());
exit(1);
}
error = gdb_server.LaunchProcess ();
if (error.Fail ())
{
fprintf (stderr, "error: failed to launch '%s': %s\n", argv[0], error.AsCString());
exit(1);
}
}
Error
writeSocketIdToPipe(Pipe &port_pipe, const std::string &socket_id)
{
size_t bytes_written = 0;
// Write the port number as a C string with the NULL terminator.
return port_pipe.Write(socket_id.c_str(), socket_id.size() + 1, bytes_written);
}
Error
writeSocketIdToPipe(const char *const named_pipe_path, const std::string &socket_id)
{
Pipe port_name_pipe;
// Wait for 10 seconds for pipe to be opened.
auto error = port_name_pipe.OpenAsWriterWithTimeout(named_pipe_path, false,
std::chrono::seconds{10});
if (error.Fail())
return error;
return writeSocketIdToPipe(port_name_pipe, socket_id);
}
Error
writeSocketIdToPipe(int unnamed_pipe_fd, const std::string &socket_id)
{
#if defined(_WIN32)
return Error("Unnamed pipes are not supported on Windows.");
#else
Pipe port_pipe{Pipe::kInvalidDescriptor, unnamed_pipe_fd};
return writeSocketIdToPipe(port_pipe, socket_id);
#endif
}
void
ConnectToRemote(MainLoop &mainloop, GDBRemoteCommunicationServerLLGS &gdb_server,
bool reverse_connect, const char *const host_and_port,
const char *const progname, const char *const subcommand,
const char *const named_pipe_path, int unnamed_pipe_fd)
{
Error error;
if (host_and_port && host_and_port[0])
{
// Parse out host and port.
std::string final_host_and_port;
std::string connection_host;
std::string connection_port;
uint32_t connection_portno = 0;
// If host_and_port starts with ':', default the host to be "localhost" and expect the remainder to be the port.
if (host_and_port[0] == ':')
final_host_and_port.append ("localhost");
final_host_and_port.append (host_and_port);
const std::string::size_type colon_pos = final_host_and_port.find (':');
if (colon_pos != std::string::npos)
{
connection_host = final_host_and_port.substr (0, colon_pos);
connection_port = final_host_and_port.substr (colon_pos + 1);
connection_portno = StringConvert::ToUInt32 (connection_port.c_str (), 0);
}
std::unique_ptr<Connection> connection_up;
if (reverse_connect)
{
// llgs will connect to the gdb-remote client.
// Ensure we have a port number for the connection.
if (connection_portno == 0)
{
fprintf (stderr, "error: port number must be specified on when using reverse connect");
exit (1);
}
// Build the connection string.
char connection_url[512];
snprintf(connection_url, sizeof(connection_url), "connect://%s", final_host_and_port.c_str ());
// Create the connection.
connection_up.reset(new ConnectionFileDescriptor);
auto connection_result = connection_up->Connect (connection_url, &error);
if (connection_result != eConnectionStatusSuccess)
{
fprintf (stderr, "error: failed to connect to client at '%s' (connection status: %d)", connection_url, static_cast<int> (connection_result));
exit (-1);
}
if (error.Fail ())
{
fprintf (stderr, "error: failed to connect to client at '%s': %s", connection_url, error.AsCString ());
exit (-1);
}
}
else
{
std::unique_ptr<Acceptor> acceptor_up(Acceptor::Create(final_host_and_port, false, error));
if (error.Fail())
{
fprintf(stderr, "failed to create acceptor: %s", error.AsCString());
exit(1);
}
error = acceptor_up->Listen(1);
if (error.Fail())
{
fprintf(stderr, "failed to listen: %s\n", error.AsCString());
exit(1);
}
const std::string socket_id = acceptor_up->GetLocalSocketId();
if (!socket_id.empty())
{
// If we have a named pipe to write the socket id back to, do that now.
if (named_pipe_path && named_pipe_path[0])
{
error = writeSocketIdToPipe (named_pipe_path, socket_id);
if (error.Fail ())
fprintf (stderr, "failed to write to the named pipe \'%s\': %s",
named_pipe_path, error.AsCString());
}
// If we have an unnamed pipe to write the socket id back to, do that now.
else if (unnamed_pipe_fd >= 0)
{
error = writeSocketIdToPipe(unnamed_pipe_fd, socket_id);
if (error.Fail())
fprintf(stderr, "failed to write to the unnamed pipe: %s",
error.AsCString());
}
}
else
{
fprintf (stderr, "unable to get the socket id for the listening connection\n");
}
Connection* conn = nullptr;
error = acceptor_up->Accept(false, conn);
if (error.Fail())
{
printf ("failed to accept new connection: %s\n", error.AsCString());
exit(1);
}
connection_up.reset(conn);
}
error = gdb_server.InitializeConnection (std::move(connection_up));
if (error.Fail())
{
fprintf(stderr, "Failed to initialize connection: %s\n", error.AsCString());
exit(-1);
}
printf ("Connection established.\n");
}
}
//----------------------------------------------------------------------
// main
//----------------------------------------------------------------------
int
main_gdbserver (int argc, char *argv[])
{
Error error;
MainLoop mainloop;
#ifndef _WIN32
// Setup signal handlers first thing.
signal (SIGPIPE, signal_handler);
MainLoop::SignalHandleUP sighup_handle = mainloop.RegisterSignal(SIGHUP, sighup_handler, error);
#endif
#ifdef __linux__
// Block delivery of SIGCHLD on linux. NativeProcessLinux will read it using signalfd.
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
pthread_sigmask(SIG_BLOCK, &set, NULL);
#endif
const char *progname = argv[0];
const char *subcommand = argv[1];
argc--;
argv++;
int long_option_index = 0;
int ch;
std::string platform_name;
std::string attach_target;
std::string named_pipe_path;
std::string log_file;
StringRef log_channels; // e.g. "lldb process threads:gdb-remote default:linux all"
int unnamed_pipe_fd = -1;
bool reverse_connect = false;
// ProcessLaunchInfo launch_info;
ProcessAttachInfo attach_info;
bool show_usage = false;
int option_error = 0;
#if __GLIBC__
optind = 0;
#else
optreset = 1;
optind = 1;
#endif
std::string short_options(OptionParser::GetShortOptionString(g_long_options));
while ((ch = getopt_long_only(argc, argv, short_options.c_str(), g_long_options, &long_option_index)) != -1)
{
switch (ch)
{
case 0: // Any optional that auto set themselves will return 0
break;
case 'l': // Set Log File
if (optarg && optarg[0])
log_file.assign(optarg);
break;
case 'c': // Log Channels
if (optarg && optarg[0])
log_channels = StringRef(optarg);
break;
case 'p': // platform name
if (optarg && optarg[0])
platform_name = optarg;
break;
case 'N': // named pipe
if (optarg && optarg[0])
named_pipe_path = optarg;
break;
case 'U': // unnamed pipe
if (optarg && optarg[0])
unnamed_pipe_fd = StringConvert::ToUInt32(optarg, -1);
case 'r':
// Do nothing, native regs is the default these days
break;
case 'R':
reverse_connect = true;
break;
#ifndef _WIN32
case 'S':
// Put llgs into a new session. Terminals group processes
// into sessions and when a special terminal key sequences
// (like control+c) are typed they can cause signals to go out to
// all processes in a session. Using this --setsid (-S) option
// will cause debugserver to run in its own sessions and be free
// from such issues.
//
// This is useful when llgs is spawned from a command
// line application that uses llgs to do the debugging,
// yet that application doesn't want llgs receiving the
// signals sent to the session (i.e. dying when anyone hits ^C).
{
const ::pid_t new_sid = setsid();
if (new_sid == -1)
{
const char *errno_str = strerror(errno);
fprintf (stderr, "failed to set new session id for %s (%s)\n", LLGS_PROGRAM_NAME, errno_str ? errno_str : "<no error string>");
}
}
break;
#endif
case 'a': // attach {pid|process_name}
if (optarg && optarg[0])
attach_target = optarg;
break;
case 'h': /* fall-through is intentional */
case '?':
show_usage = true;
break;
}
}
if (show_usage || option_error)
{
display_usage(progname, subcommand);
exit(option_error);
}
if (!LLDBServerUtilities::SetupLogging(log_file, log_channels, 0))
return -1;
Log *log(lldb_private::GetLogIfAnyCategoriesSet (GDBR_LOG_VERBOSE));
if (log)
{
log->Printf ("lldb-server launch");
for (int i = 0; i < argc; i++)
{
log->Printf ("argv[%i] = '%s'", i, argv[i]);
}
}
// Skip any options we consumed with getopt_long_only.
argc -= optind;
argv += optind;
if (argc == 0)
{
display_usage(progname, subcommand);
exit(255);
}
// Setup the platform that GDBRemoteCommunicationServerLLGS will use.
lldb::PlatformSP platform_sp = setup_platform (platform_name);
GDBRemoteCommunicationServerLLGS gdb_server (platform_sp, mainloop);
const char *const host_and_port = argv[0];
argc -= 1;
argv += 1;
// Any arguments left over are for the program that we need to launch. If there
// are no arguments, then the GDB server will start up and wait for an 'A' packet
// to launch a program, or a vAttach packet to attach to an existing process, unless
// explicitly asked to attach with the --attach={pid|program_name} form.
if (!attach_target.empty ())
handle_attach (gdb_server, attach_target);
else if (argc > 0)
handle_launch (gdb_server, argc, argv);
// Print version info.
printf("%s-%s", LLGS_PROGRAM_NAME, LLGS_VERSION_STR);
ConnectToRemote(mainloop, gdb_server, reverse_connect,
host_and_port, progname, subcommand,
named_pipe_path.c_str(), unnamed_pipe_fd);
if (! gdb_server.IsConnected())
{
fprintf (stderr, "no connection information provided, unable to run\n");
display_usage (progname, subcommand);
return 1;
}
mainloop.Run();
fprintf(stderr, "lldb-server exiting...\n");
return 0;
}