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");
}
Status ProcessFreeBSD::DoLaunch(Module *module,
ProcessLaunchInfo &launch_info) {
Status error;
assert(m_monitor == NULL);
FileSpec working_dir = launch_info.GetWorkingDirectory();
if (working_dir) {
FileSystem::Instance().Resolve(working_dir);
if (!FileSystem::Instance().IsDirectory(working_dir.GetPath())) {
error.SetErrorStringWithFormat("No such file or directory: %s",
working_dir.GetCString());
return error;
}
}
SetPrivateState(eStateLaunching);
const lldb_private::FileAction *file_action;
// Default of empty will mean to use existing open file descriptors
FileSpec stdin_file_spec{};
FileSpec stdout_file_spec{};
FileSpec stderr_file_spec{};
const FileSpec dbg_pts_file_spec{launch_info.GetPTY().GetSlaveName(NULL, 0)};
file_action = launch_info.GetFileActionForFD(STDIN_FILENO);
stdin_file_spec =
GetFileSpec(file_action, stdin_file_spec, dbg_pts_file_spec);
file_action = launch_info.GetFileActionForFD(STDOUT_FILENO);
stdout_file_spec =
GetFileSpec(file_action, stdout_file_spec, dbg_pts_file_spec);
file_action = launch_info.GetFileActionForFD(STDERR_FILENO);
stderr_file_spec =
GetFileSpec(file_action, stderr_file_spec, dbg_pts_file_spec);
m_monitor = new ProcessMonitor(
this, module, launch_info.GetArguments().GetConstArgumentVector(),
launch_info.GetEnvironment(), stdin_file_spec, stdout_file_spec,
stderr_file_spec, working_dir, launch_info, error);
m_module = module;
if (!error.Success())
return error;
int terminal = m_monitor->GetTerminalFD();
if (terminal >= 0) {
// The reader thread will close the file descriptor when done, so we pass it a
// copy.
#ifdef F_DUPFD_CLOEXEC
int stdio = fcntl(terminal, F_DUPFD_CLOEXEC, 0);
if (stdio == -1) {
error.SetErrorToErrno();
return error;
}
#else
// Special case when F_DUPFD_CLOEXEC does not exist (Debian kFreeBSD)
int stdio = fcntl(terminal, F_DUPFD, 0);
if (stdio == -1) {
error.SetErrorToErrno();
return error;
}
stdio = fcntl(terminal, F_SETFD, FD_CLOEXEC);
if (stdio == -1) {
error.SetErrorToErrno();
return error;
}
#endif
SetSTDIOFileDescriptor(stdio);
}
SetID(m_monitor->GetPID());
return error;
}
