Error
Host::LaunchProcessPosixSpawn(const char *exe_path, const ProcessLaunchInfo &launch_info, lldb::pid_t &pid)
{
Error error;
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
posix_spawnattr_t attr;
error.SetError( ::posix_spawnattr_init (&attr), eErrorTypePOSIX);
if (error.Fail() || log)
error.PutToLog(log, "::posix_spawnattr_init ( &attr )");
if (error.Fail())
return error;
// Make a quick class that will cleanup the posix spawn attributes in case
// we return in the middle of this function.
lldb_utility::CleanUp <posix_spawnattr_t *, int> posix_spawnattr_cleanup(&attr, posix_spawnattr_destroy);
sigset_t no_signals;
sigset_t all_signals;
sigemptyset (&no_signals);
sigfillset (&all_signals);
::posix_spawnattr_setsigmask(&attr, &no_signals);
#if defined (__linux__) || defined (__FreeBSD__)
::posix_spawnattr_setsigdefault(&attr, &no_signals);
#else
::posix_spawnattr_setsigdefault(&attr, &all_signals);
#endif
short flags = GetPosixspawnFlags(launch_info);
error.SetError( ::posix_spawnattr_setflags (&attr, flags), eErrorTypePOSIX);
if (error.Fail() || log)
error.PutToLog(log, "::posix_spawnattr_setflags ( &attr, flags=0x%8.8x )", flags);
if (error.Fail())
return error;
// posix_spawnattr_setbinpref_np appears to be an Apple extension per:
// http://www.unix.com/man-page/OSX/3/posix_spawnattr_setbinpref_np/
#if defined (__APPLE__) && !defined (__arm__)
// Don't set the binpref if a shell was provided. After all, that's only going to affect what version of the shell
// is launched, not what fork of the binary is launched. We insert "arch --arch <ARCH> as part of the shell invocation
// to do that job on OSX.
if (launch_info.GetShell() == nullptr)
{
// We don't need to do this for ARM, and we really shouldn't now that we
// have multiple CPU subtypes and no posix_spawnattr call that allows us
// to set which CPU subtype to launch...
const ArchSpec &arch_spec = launch_info.GetArchitecture();
cpu_type_t cpu = arch_spec.GetMachOCPUType();
cpu_type_t sub = arch_spec.GetMachOCPUSubType();
if (cpu != 0 &&
cpu != static_cast<cpu_type_t>(UINT32_MAX) &&
cpu != static_cast<cpu_type_t>(LLDB_INVALID_CPUTYPE) &&
!(cpu == 0x01000007 && sub == 8)) // If haswell is specified, don't try to set the CPU type or we will fail
{
size_t ocount = 0;
error.SetError( ::posix_spawnattr_setbinpref_np (&attr, 1, &cpu, &ocount), eErrorTypePOSIX);
if (error.Fail() || log)
error.PutToLog(log, "::posix_spawnattr_setbinpref_np ( &attr, 1, cpu_type = 0x%8.8x, count => %llu )", cpu, (uint64_t)ocount);
if (error.Fail() || ocount != 1)
return error;
}
}
#endif
const char *tmp_argv[2];
char * const *argv = (char * const*)launch_info.GetArguments().GetConstArgumentVector();
char * const *envp = (char * const*)launch_info.GetEnvironmentEntries().GetConstArgumentVector();
if (argv == NULL)
{
// posix_spawn gets very unhappy if it doesn't have at least the program
// name in argv[0]. One of the side affects I have noticed is the environment
// variables don't make it into the child process if "argv == NULL"!!!
tmp_argv[0] = exe_path;
tmp_argv[1] = NULL;
argv = (char * const*)tmp_argv;
}
#if !defined (__APPLE__)
// manage the working directory
char current_dir[PATH_MAX];
current_dir[0] = '\0';
#endif
FileSpec working_dir{launch_info.GetWorkingDirectory()};
if (working_dir)
{
#if defined (__APPLE__)
// Set the working directory on this thread only
if (__pthread_chdir(working_dir.GetCString()) < 0) {
if (errno == ENOENT) {
error.SetErrorStringWithFormat("No such file or directory: %s",
working_dir.GetCString());
} else if (errno == ENOTDIR) {
error.SetErrorStringWithFormat("Path doesn't name a directory: %s",
working_dir.GetCString());
} else {
error.SetErrorStringWithFormat("An unknown error occurred when changing directory for process execution.");
}
return error;
}
#else
if (::getcwd(current_dir, sizeof(current_dir)) == NULL)
{
error.SetError(errno, eErrorTypePOSIX);
error.LogIfError(log, "unable to save the current directory");
return error;
}
if (::chdir(working_dir.GetCString()) == -1)
{
error.SetError(errno, eErrorTypePOSIX);
error.LogIfError(log, "unable to change working directory to %s",
working_dir.GetCString());
return error;
}
#endif
}
::pid_t result_pid = LLDB_INVALID_PROCESS_ID;
const size_t num_file_actions = launch_info.GetNumFileActions ();
if (num_file_actions > 0)
{
posix_spawn_file_actions_t file_actions;
error.SetError( ::posix_spawn_file_actions_init (&file_actions), eErrorTypePOSIX);
if (error.Fail() || log)
error.PutToLog(log, "::posix_spawn_file_actions_init ( &file_actions )");
if (error.Fail())
return error;
// Make a quick class that will cleanup the posix spawn attributes in case
// we return in the middle of this function.
lldb_utility::CleanUp <posix_spawn_file_actions_t *, int> posix_spawn_file_actions_cleanup (&file_actions, posix_spawn_file_actions_destroy);
for (size_t i=0; i<num_file_actions; ++i)
{
const FileAction *launch_file_action = launch_info.GetFileActionAtIndex(i);
if (launch_file_action)
{
if (!AddPosixSpawnFileAction(&file_actions, launch_file_action, log, error))
return error;
}
}
error.SetError(::posix_spawnp(&result_pid, exe_path, &file_actions, &attr, argv, envp), eErrorTypePOSIX);
if (error.Fail() || log)
{
error.PutToLog(log, "::posix_spawnp ( pid => %i, path = '%s', file_actions = %p, attr = %p, argv = %p, envp = %p )", result_pid,
exe_path, static_cast<void *>(&file_actions), static_cast<void *>(&attr), reinterpret_cast<const void *>(argv),
reinterpret_cast<const void *>(envp));
if (log)
{
for (int ii=0; argv[ii]; ++ii)
log->Printf("argv[%i] = '%s'", ii, argv[ii]);
}
}
}
else
{
error.SetError(::posix_spawnp(&result_pid, exe_path, NULL, &attr, argv, envp), eErrorTypePOSIX);
if (error.Fail() || log)
{
error.PutToLog(log, "::posix_spawnp ( pid => %i, path = '%s', file_actions = NULL, attr = %p, argv = %p, envp = %p )",
result_pid, exe_path, static_cast<void *>(&attr), reinterpret_cast<const void *>(argv),
reinterpret_cast<const void *>(envp));
if (log)
{
for (int ii=0; argv[ii]; ++ii)
log->Printf("argv[%i] = '%s'", ii, argv[ii]);
}
}
}
pid = result_pid;
if (working_dir)
{
#if defined (__APPLE__)
// No more thread specific current working directory
__pthread_fchdir (-1);
#else
if (::chdir(current_dir) == -1 && error.Success())
{
error.SetError(errno, eErrorTypePOSIX);
error.LogIfError(log, "unable to change current directory back to %s",
current_dir);
}
#endif
}
return error;
}
Error
PlatformRemoteGDBServer::LaunchProcess (ProcessLaunchInfo &launch_info)
{
Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_PLATFORM));
Error error;
if (log)
log->Printf ("PlatformRemoteGDBServer::%s() called", __FUNCTION__);
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);
if (file_action->GetAction () != FileAction::eFileActionOpen)
continue;
switch(file_action->GetFD())
{
case STDIN_FILENO:
m_gdb_client.SetSTDIN(file_action->GetFileSpec());
break;
case STDOUT_FILENO:
m_gdb_client.SetSTDOUT(file_action->GetFileSpec());
break;
case STDERR_FILENO:
m_gdb_client.SetSTDERR(file_action->GetFileSpec());
break;
}
}
m_gdb_client.SetDisableASLR (launch_info.GetFlags().Test (eLaunchFlagDisableASLR));
m_gdb_client.SetDetachOnError (launch_info.GetFlags().Test (eLaunchFlagDetachOnError));
FileSpec working_dir = launch_info.GetWorkingDirectory();
if (working_dir)
{
m_gdb_client.SetWorkingDir(working_dir);
}
// Send the environment and the program + arguments after we connect
const char **envp = launch_info.GetEnvironmentEntries().GetConstArgumentVector();
if (envp)
{
const char *env_entry;
for (int i=0; (env_entry = envp[i]); ++i)
{
if (m_gdb_client.SendEnvironmentPacket(env_entry) != 0)
break;
}
}
ArchSpec arch_spec = launch_info.GetArchitecture();
const char *arch_triple = arch_spec.GetTriple().str().c_str();
m_gdb_client.SendLaunchArchPacket(arch_triple);
if (log)
log->Printf ("PlatformRemoteGDBServer::%s() set launch architecture triple to '%s'", __FUNCTION__, arch_triple ? arch_triple : "<NULL>");
int arg_packet_err;
{
// Scope for the scoped timeout object
process_gdb_remote::GDBRemoteCommunication::ScopedTimeout timeout(m_gdb_client, 5);
arg_packet_err = m_gdb_client.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 (pid != LLDB_INVALID_PROCESS_ID)
{
launch_info.SetProcessID (pid);
if (log)
log->Printf ("PlatformRemoteGDBServer::%s() pid %" PRIu64 " launched successfully", __FUNCTION__, pid);
}
else
{
if (log)
log->Printf ("PlatformRemoteGDBServer::%s() launch succeeded but we didn't get a valid process id back!", __FUNCTION__);
error.SetErrorString ("failed to get PID");
}
}
else
{
error.SetErrorString (error_str.c_str());
if (log)
log->Printf ("PlatformRemoteGDBServer::%s() launch failed: %s", __FUNCTION__, error.AsCString ());
}
}
else
{
error.SetErrorStringWithFormat("'A' packet returned an error: %i", arg_packet_err);
}
return error;
}
static void LLVM_ATTRIBUTE_NORETURN ChildFunc(int error_fd,
const ProcessLaunchInfo &info) {
if (info.GetFlags().Test(eLaunchFlagLaunchInSeparateProcessGroup)) {
if (setpgid(0, 0) != 0)
ExitWithError(error_fd, "setpgid");
}
for (size_t i = 0; i < info.GetNumFileActions(); ++i) {
const FileAction &action = *info.GetFileActionAtIndex(i);
switch (action.GetAction()) {
case FileAction::eFileActionClose:
if (close(action.GetFD()) != 0)
ExitWithError(error_fd, "close");
break;
case FileAction::eFileActionDuplicate:
if (dup2(action.GetFD(), action.GetActionArgument()) == -1)
ExitWithError(error_fd, "dup2");
break;
case FileAction::eFileActionOpen:
DupDescriptor(error_fd, action.GetFileSpec(), action.GetFD(),
action.GetActionArgument());
break;
case FileAction::eFileActionNone:
break;
}
}
const char **argv = info.GetArguments().GetConstArgumentVector();
// Change working directory
if (info.GetWorkingDirectory() &&
0 != ::chdir(info.GetWorkingDirectory().GetCString()))
ExitWithError(error_fd, "chdir");
DisableASLRIfRequested(error_fd, info);
Environment env = info.GetEnvironment();
FixupEnvironment(env);
Environment::Envp envp = env.getEnvp();
// Clear the signal mask to prevent the child from being affected by any
// masking done by the parent.
sigset_t set;
if (sigemptyset(&set) != 0 ||
pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0)
ExitWithError(error_fd, "pthread_sigmask");
if (info.GetFlags().Test(eLaunchFlagDebug)) {
// Do not inherit setgid powers.
if (setgid(getgid()) != 0)
ExitWithError(error_fd, "setgid");
// HACK:
// Close everything besides stdin, stdout, and stderr that has no file
// action to avoid leaking. Only do this when debugging, as elsewhere we
// actually rely on passing open descriptors to child processes.
for (int fd = 3; fd < sysconf(_SC_OPEN_MAX); ++fd)
if (!info.GetFileActionForFD(fd) && fd != error_fd)
close(fd);
// Start tracing this child that is about to exec.
if (ptrace(PT_TRACE_ME, 0, nullptr, 0) == -1)
ExitWithError(error_fd, "ptrace");
}
// Execute. We should never return...
execve(argv[0], const_cast<char *const *>(argv), envp);
#if defined(__linux__)
if (errno == ETXTBSY) {
// On android M and earlier we can get this error because the adb daemon
// can hold a write handle on the executable even after it has finished
// uploading it. This state lasts only a short time and happens only when
// there are many concurrent adb commands being issued, such as when
// running the test suite. (The file remains open when someone does an "adb
// shell" command in the fork() child before it has had a chance to exec.)
// Since this state should clear up quickly, wait a while and then give it
// one more go.
usleep(50000);
execve(argv[0], const_cast<char *const *>(argv), envp);
}
#endif
// ...unless exec fails. In which case we definitely need to end the child
// here.
ExitWithError(error_fd, "execve");
}
static void LLVM_ATTRIBUTE_NORETURN ChildFunc(int error_fd,
const ProcessLaunchInfo &info) {
// First, make sure we disable all logging. If we are logging to stdout, our
// logs can be
// mistaken for inferior output.
Log::DisableAllLogChannels(nullptr);
// Do not inherit setgid powers.
if (setgid(getgid()) != 0)
ExitWithError(error_fd, "setgid");
if (info.GetFlags().Test(eLaunchFlagLaunchInSeparateProcessGroup)) {
if (setpgid(0, 0) != 0)
ExitWithError(error_fd, "setpgid");
}
for (size_t i = 0; i < info.GetNumFileActions(); ++i) {
const FileAction &action = *info.GetFileActionAtIndex(i);
switch (action.GetAction()) {
case FileAction::eFileActionClose:
if (close(action.GetFD()) != 0)
ExitWithError(error_fd, "close");
break;
case FileAction::eFileActionDuplicate:
if (dup2(action.GetFD(), action.GetActionArgument()) == -1)
ExitWithError(error_fd, "dup2");
break;
case FileAction::eFileActionOpen:
DupDescriptor(error_fd, action.GetFileSpec(), action.GetFD(),
action.GetActionArgument());
break;
case FileAction::eFileActionNone:
break;
}
}
const char **argv = info.GetArguments().GetConstArgumentVector();
// Change working directory
if (info.GetWorkingDirectory() &&
0 != ::chdir(info.GetWorkingDirectory().GetCString()))
ExitWithError(error_fd, "chdir");
// Disable ASLR if requested.
if (info.GetFlags().Test(lldb::eLaunchFlagDisableASLR)) {
const unsigned long personality_get_current = 0xffffffff;
int value = personality(personality_get_current);
if (value == -1)
ExitWithError(error_fd, "personality get");
value = personality(ADDR_NO_RANDOMIZE | value);
if (value == -1)
ExitWithError(error_fd, "personality set");
}
Args env = info.GetEnvironmentEntries();
FixupEnvironment(env);
const char **envp = env.GetConstArgumentVector();
// Clear the signal mask to prevent the child from being affected by
// any masking done by the parent.
sigset_t set;
if (sigemptyset(&set) != 0 ||
pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0)
ExitWithError(error_fd, "pthread_sigmask");
if (info.GetFlags().Test(eLaunchFlagDebug)) {
// HACK:
// Close everything besides stdin, stdout, and stderr that has no file
// action to avoid leaking. Only do this when debugging, as elsewhere we
// actually rely on
// passing open descriptors to child processes.
for (int fd = 3; fd < sysconf(_SC_OPEN_MAX); ++fd)
if (!info.GetFileActionForFD(fd) && fd != error_fd)
close(fd);
// Start tracing this child that is about to exec.
if (ptrace(PTRACE_TRACEME, 0, nullptr, nullptr) == -1)
ExitWithError(error_fd, "ptrace");
}
// Execute. We should never return...
execve(argv[0], const_cast<char *const *>(argv),
const_cast<char *const *>(envp));
if (errno == ETXTBSY) {
// On android M and earlier we can get this error because the adb deamon can
// hold a write
// handle on the executable even after it has finished uploading it. This
// state lasts
// only a short time and happens only when there are many concurrent adb
// commands being
// issued, such as when running the test suite. (The file remains open when
// someone does
// an "adb shell" command in the fork() child before it has had a chance to
// exec.) Since
// this state should clear up quickly, wait a while and then give it one
// more go.
usleep(50000);
execve(argv[0], const_cast<char *const *>(argv),
const_cast<char *const *>(envp));
}
// ...unless exec fails. In which case we definitely need to end the child
// here.
ExitWithError(error_fd, "execve");
}