/* spawn.cc This file is part of Cygwin. This software is a copyrighted work licensed under the terms of the Cygwin license. Please consult the file "CYGWIN_LICENSE" for details. */ #include "winsup.h" #include #include #include #include #include #include #include #include "cygerrno.h" #include "security.h" #include "sigproc.h" #include "pinfo.h" #include "path.h" #include "fhandler.h" #include "dtable.h" #include "cygheap.h" #include "child_info.h" #include "environ.h" #include "cygtls.h" #include "tls_pbuf.h" #include "winf.h" #include "ntdll.h" #include "shared_info.h" /* Add .exe to PROG if not already present and see if that exists. If not, return PROG (converted from posix to win32 rules if necessary). The result is always BUF. Returns (possibly NULL) suffix */ static const char * perhaps_suffix (const char *prog, path_conv& buf, int& err, unsigned opt) { const char *ext; err = 0; debug_printf ("prog '%s'", prog); buf.check (prog, PC_SYM_FOLLOW | PC_NULLEMPTY | PC_POSIX, stat_suffixes); if (buf.isdir ()) { err = EACCES; ext = NULL; } else if (!buf.exists ()) { err = ENOENT; ext = NULL; } else if (buf.known_suffix ()) ext = buf.get_win32 () + (buf.known_suffix () - buf.get_win32 ()); else ext = strchr (buf.get_win32 (), '\0'); debug_printf ("buf %s, suffix found '%s'", (char *) buf.get_win32 (), ext); return ext; } /* Find an executable name, possibly by appending known executable suffixes to it. The path_conv struct 'buf' is filled and contains both, win32 and posix path of the target file. Any found suffix is returned in known_suffix. Eventually the posix path in buf is overwritten with the exact path as it gets constructed for the path search. The reason is that the path is used to create argv[0] in av::setup, and this requires that the filename stays intact, instead of being resolved if the file is a symlink. If the file is not found and !FE_NNF then the POSIX version of name is placed in buf and returned. Otherwise the contents of buf is undefined and NULL is returned. */ const char * find_exec (const char *name, path_conv& buf, const char *search, unsigned opt, const char **known_suffix) { const char *suffix = ""; const char *retval = NULL; tmp_pathbuf tp; char *tmp_path; char *tmp = tp.c_get (); bool has_slash = !!strpbrk (name, "/\\"); int err = 0; bool eopath = false; debug_printf ("find_exec (%s)", name); /* Check to see if file can be opened as is first. */ if ((has_slash || opt & FE_CWD) && (suffix = perhaps_suffix (name, buf, err, opt)) != NULL) { /* Overwrite potential symlink target with original path. See comment preceeding this method. */ tmp_path = tmp; if (!has_slash) tmp_path = stpcpy (tmp, "./"); stpcpy (tmp_path, name); buf.set_posix (tmp); retval = buf.get_posix (); goto out; } const char *path; /* If it starts with a slash, it's a PATH-like pathlist. Otherwise it's the name of an environment variable. */ if (strchr (search, '/')) *stpncpy (tmp, search, NT_MAX_PATH - 1) = '\0'; else if (has_slash || isdrive (name)) goto errout; /* Search the current directory when PATH is absent. This feature is added for Linux compatibility, but it is deprecated. POSIX notes that a conforming application shall use an explicit path name to specify the current working directory. */ else if (!(path = getenv (search)) || !*path) strcpy (tmp, "."); else *stpncpy (tmp, path, NT_MAX_PATH - 1) = '\0'; path = tmp; debug_printf ("searchpath %s", path); tmp_path = tp.c_get (); do { char *eotmp = strccpy (tmp_path, &path, ':'); if (*path) path++; else eopath = true; /* An empty path or '.' means the current directory, but we've already tried that. */ if ((opt & FE_CWD) && (tmp_path[0] == '\0' || (tmp_path[0] == '.' && tmp_path[1] == '\0'))) continue; /* An empty path means the current directory. This feature is added for Linux compatibility, but it is deprecated. POSIX notes that a conforming application shall use an explicit pathname to specify the current working directory. */ else if (tmp_path[0] == '\0') eotmp = stpcpy (tmp_path, "."); *eotmp++ = '/'; stpcpy (eotmp, name); debug_printf ("trying %s", tmp_path); int err1; if ((suffix = perhaps_suffix (tmp_path, buf, err1, opt)) != NULL) { if (buf.has_acls () && check_file_access (buf, X_OK, true)) continue; /* Overwrite potential symlink target with original path. See comment preceeding this method. */ buf.set_posix (tmp_path); retval = buf.get_posix (); goto out; } } while (!eopath); errout: /* Couldn't find anything in the given path. Take the appropriate action based on FE_NNF. */ if (!(opt & FE_NNF)) { buf.check (name, PC_SYM_FOLLOW | PC_POSIX); retval = buf.get_posix (); } out: debug_printf ("%s = find_exec (%s)", (char *) buf.get_posix (), name); if (known_suffix) *known_suffix = suffix ?: strchr (buf.get_win32 (), '\0'); if (!retval && err) set_errno (err); return retval; } /* Utility for child_info_spawn::worker. */ static HANDLE handle (int fd, bool writing) { HANDLE h; cygheap_fdget cfd (fd); if (cfd < 0) h = INVALID_HANDLE_VALUE; else if (cfd->close_on_exec ()) h = INVALID_HANDLE_VALUE; else if (!writing) h = cfd->get_handle_nat (); else h = cfd->get_output_handle_nat (); return h; } int iscmd (const char *argv0, const char *what) { int n; n = strlen (argv0) - strlen (what); if (n >= 2 && argv0[1] != ':') return 0; return n >= 0 && strcasematch (argv0 + n, what) && (n == 0 || isdirsep (argv0[n - 1])); } #define ILLEGAL_SIG_FUNC_PTR ((_sig_func_ptr) (-2)) struct system_call_handle { _sig_func_ptr oldint; _sig_func_ptr oldquit; sigset_t oldmask; __pthread_cleanup_handler cleanup_handler; bool is_system_call () { return oldint != ILLEGAL_SIG_FUNC_PTR; } system_call_handle (bool issystem) { if (!issystem) oldint = ILLEGAL_SIG_FUNC_PTR; else { sig_send (NULL, __SIGHOLD); oldint = NULL; } } void arm() { if (is_system_call ()) { sigset_t child_block; oldint = signal (SIGINT, SIG_IGN); oldquit = signal (SIGQUIT, SIG_IGN); sigemptyset (&child_block); sigaddset (&child_block, SIGCHLD); sigprocmask (SIG_BLOCK, &child_block, &oldmask); sig_send (NULL, __SIGNOHOLD); cleanup_handler = { system_call_handle::cleanup, this, NULL }; _pthread_cleanup_push (&cleanup_handler); } } ~system_call_handle () { if (is_system_call ()) _pthread_cleanup_pop (1); } static void cleanup (void *arg) { # define this_ ((system_call_handle *) arg) if (this_->is_system_call ()) { signal (SIGINT, this_->oldint); signal (SIGQUIT, this_->oldquit); sigprocmask (SIG_SETMASK, &(this_->oldmask), NULL); } } # undef this_ }; child_info_spawn NO_COPY ch_spawn; extern "C" void __posix_spawn_sem_release (void *sem, int error); extern DWORD mutex_timeout; /* defined in fhandler_termios.cc */ int child_info_spawn::worker (const char *prog_arg, const char *const *argv, const char *const envp[], int mode, int in__stdin, int in__stdout) { bool rc; int res = -1; /* Check if we have been called from exec{lv}p or spawn{lv}p and mask mode to keep only the spawn mode. */ bool p_type_exec = !!(mode & _P_PATH_TYPE_EXEC); mode = _P_MODE (mode); if (prog_arg == NULL) { syscall_printf ("prog_arg is NULL"); set_errno (EFAULT); /* As on Linux. */ return -1; } if (!prog_arg[0]) { syscall_printf ("prog_arg is empty"); set_errno (ENOENT); /* Per POSIX */ return -1; } syscall_printf ("mode = %d, prog_arg = %.9500s", mode, prog_arg); /* FIXME: This is no error condition on Linux. */ if (argv == NULL) { syscall_printf ("argv is NULL"); set_errno (EINVAL); return -1; } av newargv; linebuf cmd; PWCHAR envblock = NULL; path_conv real_path; bool reset_sendsig = false; tmp_pathbuf tp; PWCHAR runpath = tp.w_get (); int c_flags; STARTUPINFOW si = {}; int looped = 0; fhandler_termios::spawn_worker term_spawn_worker; system_call_handle system_call (mode == _P_SYSTEM); __try { child_info_types chtype; if (mode == _P_OVERLAY) chtype = _CH_EXEC; else chtype = _CH_SPAWN; moreinfo = cygheap_exec_info::alloc (); /* CreateProcess takes one long string that is the command line (sigh). We need to quote any argument that has whitespace or embedded "'s. */ int ac; for (ac = 0; argv[ac]; ac++) ; int err; const char *ext; if ((ext = perhaps_suffix (prog_arg, real_path, err, FE_NADA)) == NULL) { set_errno (err); res = -1; __leave; } res = newargv.setup (prog_arg, real_path, ext, ac, argv, p_type_exec); if (res) __leave; if (!real_path.iscygexec () && ::cygheap->cwd.get_error ()) { small_printf ("Error: Current working directory %s.\n" "Can't start native Windows application from here.\n\n", ::cygheap->cwd.get_error_desc ()); set_errno (::cygheap->cwd.get_error ()); res = -1; __leave; } if (real_path.iscygexec ()) { moreinfo->argc = newargv.argc; moreinfo->argv = newargv; } if ((wincmdln || !real_path.iscygexec ()) && !cmd.fromargv (newargv, real_path.get_win32 (), real_path.iscygexec ())) { res = -1; __leave; } if (mode != _P_OVERLAY || !real_path.iscygexec () || !DuplicateHandle (GetCurrentProcess (), myself.shared_handle (), GetCurrentProcess (), &moreinfo->myself_pinfo, 0, TRUE, DUPLICATE_SAME_ACCESS)) moreinfo->myself_pinfo = NULL; else VerifyHandle (moreinfo->myself_pinfo); PROCESS_INFORMATION pi; pi.hProcess = pi.hThread = NULL; pi.dwProcessId = pi.dwThreadId = 0; c_flags = GetPriorityClass (GetCurrentProcess ()); sigproc_printf ("priority class %d", c_flags); c_flags |= CREATE_SEPARATE_WOW_VDM | CREATE_UNICODE_ENVIRONMENT; /* Add CREATE_DEFAULT_ERROR_MODE flag for non-Cygwin processes so they get the default error mode instead of inheriting the mode Cygwin uses. This allows things like Windows Error Reporting/JIT debugging to work with processes launched from a Cygwin shell. */ if (winjitdebug && !real_path.iscygexec ()) c_flags |= CREATE_DEFAULT_ERROR_MODE; /* We're adding the CREATE_BREAKAWAY_FROM_JOB flag here to workaround issues with the "Program Compatibility Assistant (PCA) Service". For some reason, when starting long running sessions from mintty(*), the affected svchost.exe process takes more and more memory and at one point takes over the CPU. At this point the machine becomes unresponsive. The only way to get back to normal is to stop the entire mintty session, or to stop the PCA service. However, a process which is controlled by PCA is part of a compatibility job, which allows child processes to break away from the job. This helps to avoid this issue. First we call IsProcessInJob. It fetches the information whether or not we're part of a job 20 times faster than QueryInformationJobObject. (*) Note that this is not mintty's fault. It has just been observed with mintty in the first place. See the archives for more info: http://cygwin.com/ml/cygwin-developers/2012-02/msg00018.html */ JOBOBJECT_BASIC_LIMIT_INFORMATION jobinfo; BOOL is_in_job; if (IsProcessInJob (GetCurrentProcess (), NULL, &is_in_job) && is_in_job && QueryInformationJobObject (NULL, JobObjectBasicLimitInformation, &jobinfo, sizeof jobinfo, NULL) && (jobinfo.LimitFlags & (JOB_OBJECT_LIMIT_BREAKAWAY_OK | JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK))) { debug_printf ("Add CREATE_BREAKAWAY_FROM_JOB"); c_flags |= CREATE_BREAKAWAY_FROM_JOB; } if (mode == _P_DETACH) c_flags |= DETACHED_PROCESS; else fhandler_console::need_invisible (); if (mode != _P_OVERLAY) myself->exec_sendsig = NULL; else { /* Reset sendsig so that any process which wants to send a signal to this pid will wait for the new process to become active. Save the old value in case the exec fails. */ if (!myself->exec_sendsig) { myself->exec_sendsig = myself->sendsig; myself->exec_dwProcessId = myself->dwProcessId; myself->sendsig = NULL; reset_sendsig = true; } } USHORT len = real_path.get_nt_native_path ()->Length / sizeof (WCHAR); if (RtlEqualUnicodePathPrefix (real_path.get_nt_native_path (), &ro_u_natp, FALSE)) { runpath = real_path.get_wide_win32_path (runpath); /* If the executable path length is < MAX_PATH, make sure the long path win32 prefix is removed from the path to make subsequent not long path aware native Win32 child processes happy. */ if (len < MAX_PATH + 4) { if (runpath[5] == ':') runpath += 4; else if (len < MAX_PATH + 6) *(runpath += 6) = L'\\'; } } else if (len < NT_MAX_PATH - ro_u_globalroot.Length / sizeof (WCHAR)) { UNICODE_STRING rpath; RtlInitEmptyUnicodeString (&rpath, runpath, (NT_MAX_PATH - 1) * sizeof (WCHAR)); RtlCopyUnicodeString (&rpath, &ro_u_globalroot); RtlAppendUnicodeStringToString (&rpath, real_path.get_nt_native_path ()); } else { set_errno (ENAMETOOLONG); res = -1; __leave; } cygbench ("spawn-worker"); if (!real_path.iscygexec()) ::cygheap->fdtab.set_file_pointers_for_exec (); /* If we switch the user, merge the user's Windows environment. */ bool switch_user = ::cygheap->user.issetuid () && (::cygheap->user.saved_uid != ::cygheap->user.real_uid); moreinfo->envp = build_env (envp, envblock, moreinfo->envc, real_path.iscygexec (), switch_user ? ::cygheap->user.primary_token () : NULL); if (!moreinfo->envp || !envblock) { set_errno (E2BIG); res = -1; __leave; } set (chtype, real_path.iscygexec ()); __stdin = in__stdin; __stdout = in__stdout; record_children (); si.lpReserved2 = (LPBYTE) this; si.cbReserved2 = sizeof (*this); /* Depends on set call above. Some file types might need extra effort in the parent after CreateProcess and before copying the datastructures to the child. So we have to start the child in suspend state, unfortunately, to avoid a race condition. */ if (!newargv.win16_exe && (!iscygwin () || mode != _P_OVERLAY || ::cygheap->fdtab.need_fixup_before ())) c_flags |= CREATE_SUSPENDED; /* If a native application should be spawned, we test here if the spawning process is running in a console and, if so, if it's a foreground or background process. If it's a background process, we start the native process with the CREATE_NEW_PROCESS_GROUP flag set. This lets the native process ignore Ctrl-C by default. If we don't do that, pressing Ctrl-C in a console will break native processes running in the background, because the Ctrl-C event is sent to all processes in the console, unless they ignore it explicitely. CREATE_NEW_PROCESS_GROUP does that for us. */ pid_t ctty_pgid = ::cygheap->ctty ? ::cygheap->ctty->tc_getpgid () : 0; if (!iscygwin () && ctty_pgid && ctty_pgid != myself->pgid) c_flags |= CREATE_NEW_PROCESS_GROUP; refresh_cygheap (); if (c_flags & CREATE_NEW_PROCESS_GROUP) myself->process_state |= PID_NEW_PG; if (mode == _P_DETACH) /* all set */; else if (mode != _P_OVERLAY || !my_wr_proc_pipe) prefork (); else wr_proc_pipe = my_wr_proc_pipe; /* Don't allow child to inherit these handles if it's not a Cygwin program. wr_proc_pipe will be injected later. parent won't be used by the child so there is no reason for the child to have it open as it can confuse ps into thinking that children of windows processes are all part of the same "execed" process. FIXME: Someday, make it so that parent is never created when starting non-Cygwin processes. */ if (!iscygwin ()) { SetHandleInformation (wr_proc_pipe, HANDLE_FLAG_INHERIT, 0); SetHandleInformation (parent, HANDLE_FLAG_INHERIT, 0); } /* FIXME: racy */ if (mode != _P_OVERLAY) SetHandleInformation (my_wr_proc_pipe, HANDLE_FLAG_INHERIT, 0); parent_winpid = GetCurrentProcessId (); PSECURITY_ATTRIBUTES sa = (PSECURITY_ATTRIBUTES) alloca (1024); if (!sec_user_nih (sa, cygheap->user.sid (), well_known_authenticated_users_sid, PROCESS_QUERY_LIMITED_INFORMATION)) sa = &sec_none_nih; int fileno_stdin = in__stdin < 0 ? 0 : in__stdin; int fileno_stdout = in__stdout < 0 ? 1 : in__stdout; int fileno_stderr = 2; if (!iscygwin ()) fhandler_pipe::spawn_worker (fileno_stdin, fileno_stdout, fileno_stderr); bool no_pcon = mode != _P_OVERLAY && mode != _P_WAIT; term_spawn_worker.setup (iscygwin (), handle (fileno_stdin, false), runpath, no_pcon, reset_sendsig, envblock); /* Set up needed handles for stdio */ si.dwFlags = STARTF_USESTDHANDLES; si.hStdInput = handle (fileno_stdin, false); si.hStdOutput = handle (fileno_stdout, true); si.hStdError = handle (fileno_stderr, true); si.cb = sizeof (si); if (!iscygwin ()) init_console_handler (CTTY_IS_VALID (myself->ctty)); loop: /* When ruid != euid we create the new process under the current original account and impersonate in child, this way maintaining the different effective vs. real ids. FIXME: If ruid != euid and ruid != saved_uid we currently give up on ruid. The new process will have ruid == euid. */ ::cygheap->user.deimpersonate (); if (!real_path.iscygexec () && mode == _P_OVERLAY) myself->process_state |= PID_NOTCYGWIN; cygpid = (mode != _P_OVERLAY) ? create_cygwin_pid () : myself->pid; wchar_t wcmd[(size_t) cmd]; if (!::cygheap->user.issetuid () || (::cygheap->user.saved_uid == ::cygheap->user.real_uid && ::cygheap->user.saved_gid == ::cygheap->user.real_gid && !::cygheap->user.groups.issetgroups () && !::cygheap->user.setuid_to_restricted)) { rc = CreateProcessW (runpath, /* image name w/ full path */ cmd.wcs (wcmd), /* what was passed to exec */ sa, /* process security attrs */ sa, /* thread security attrs */ TRUE, /* inherit handles */ c_flags, envblock, /* environment */ NULL, &si, &pi); } else { /* Give access to myself */ if (mode == _P_OVERLAY) myself.set_acl(); HWINSTA hwst = NULL; HWINSTA hwst_orig = GetProcessWindowStation (); HDESK hdsk = NULL; HDESK hdsk_orig = GetThreadDesktop (GetCurrentThreadId ()); /* Don't create WindowStation and Desktop for restricted child. */ if (!::cygheap->user.setuid_to_restricted) { PSECURITY_ATTRIBUTES sa; WCHAR sid[128]; WCHAR wstname[1024] = { L'\0' }; sa = sec_user ((PSECURITY_ATTRIBUTES) alloca (1024), ::cygheap->user.sid ()); /* We're creating a window station per user, not per logon session. It doesn't make sense in terms of security to create a new window station for every logon of the same user. It just fills up the system with window stations. */ hwst = CreateWindowStationW (::cygheap->user.get_windows_id (sid), 0, GENERIC_READ | GENERIC_WRITE, sa); if (!hwst) system_printf ("CreateWindowStation failed, %E"); else if (!SetProcessWindowStation (hwst)) system_printf ("SetProcessWindowStation failed, %E"); else if (!(hdsk = CreateDesktopW (L"Default", NULL, NULL, 0, GENERIC_ALL, sa))) system_printf ("CreateDesktop failed, %E"); else { wcpcpy (wcpcpy (wstname, sid), L"\\Default"); si.lpDesktop = wstname; debug_printf ("Desktop: %W", si.lpDesktop); } } rc = CreateProcessAsUserW (::cygheap->user.primary_token (), runpath, /* image name w/ full path */ cmd.wcs (wcmd), /* what was passed to exec */ sa, /* process security attrs */ sa, /* thread security attrs */ TRUE, /* inherit handles */ c_flags, envblock, /* environment */ NULL, &si, &pi); if (hwst) { SetProcessWindowStation (hwst_orig); CloseWindowStation (hwst); } if (hdsk) { SetThreadDesktop (hdsk_orig); CloseDesktop (hdsk); } } if (mode != _P_OVERLAY) SetHandleInformation (my_wr_proc_pipe, HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT); /* Set errno now so that debugging messages from it appear before our final debugging message [this is a general rule for debugging messages]. */ if (!rc) { __seterrno (); syscall_printf ("CreateProcess failed, %E"); /* If this was a failed exec, restore the saved sendsig. */ if (reset_sendsig) { myself->sendsig = myself->exec_sendsig; myself->exec_sendsig = NULL; } myself->process_state &= ~PID_NOTCYGWIN; /* Reset handle inheritance to default when the execution of a' non-Cygwin process fails. Only need to do this for _P_OVERLAY since the handle will be closed otherwise. Don't need to do this for 'parent' since it will be closed in every case. See FIXME above. */ if (!iscygwin () && mode == _P_OVERLAY) SetHandleInformation (wr_proc_pipe, HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT); if (wr_proc_pipe == my_wr_proc_pipe) wr_proc_pipe = NULL; /* We still own it: don't nuke in destructor */ /* Restore impersonation. In case of _P_OVERLAY this isn't allowed since it would overwrite child data. */ if (mode != _P_OVERLAY) ::cygheap->user.reimpersonate (); res = -1; __leave; } /* The CREATE_SUSPENDED case is handled below */ if (iscygwin () && !(c_flags & CREATE_SUSPENDED)) strace.write_childpid (pi.dwProcessId); /* Fixup the parent data structures if needed and resume the child's main thread. */ if (::cygheap->fdtab.need_fixup_before ()) ::cygheap->fdtab.fixup_before_exec (pi.dwProcessId); /* Print the original program name here so the user can see that too. */ syscall_printf ("pid %d, prog_arg %s, cmd line %.9500s)", rc ? cygpid : (unsigned int) -1, prog_arg, (const char *) cmd); /* Name the handle similarly to proc_subproc. */ ProtectHandle1 (pi.hProcess, childhProc); if (mode == _P_OVERLAY) { myself->dwProcessId = pi.dwProcessId; strace.execing = 1; myself.hProcess = hExeced = pi.hProcess; HANDLE old_winpid_hdl = myself.shared_winpid_handle (); /* We have to create a new winpid symlink on behalf of the child process. For Cygwin processes we also have to create a reference in the child. */ myself.create_winpid_symlink (); if (real_path.iscygexec ()) DuplicateHandle (GetCurrentProcess (), myself.shared_winpid_handle (), pi.hProcess, NULL, 0, 0, DUPLICATE_SAME_ACCESS); NtClose (old_winpid_hdl); real_path.get_wide_win32_path (myself->progname); // FIXME: race? sigproc_printf ("new process name %W", myself->progname); if (!iscygwin ()) close_all_files (); } else { myself->set_has_pgid_children (); ProtectHandle (pi.hThread); pinfo child (cygpid, PID_IN_USE | (real_path.iscygexec () ? 0 : PID_NOTCYGWIN)); if (!child) { syscall_printf ("pinfo failed"); if (get_errno () != ENOMEM) set_errno (EAGAIN); res = -1; __leave; } child->dwProcessId = pi.dwProcessId; child.hProcess = pi.hProcess; real_path.get_wide_win32_path (child->progname); /* This introduces an unreferenced, open handle into the child. The purpose is to keep the pid shared memory open so that all of the fields filled out by child.remember do not disappear and so there is not a brief period during which the pid is not available. */ DuplicateHandle (GetCurrentProcess (), child.shared_handle (), pi.hProcess, NULL, 0, 0, DUPLICATE_SAME_ACCESS); if (!real_path.iscygexec ()) { /* If the child process is not a Cygwin process, we have to create a new winpid symlink and induce it into the child process as well to keep it over the lifetime of the child. */ child.create_winpid_symlink (); DuplicateHandle (GetCurrentProcess (), child.shared_winpid_handle (), pi.hProcess, NULL, 0, 0, DUPLICATE_SAME_ACCESS); } child->start_time = time (NULL); /* Register child's starting time. */ child->nice = myself->nice; postfork (child); if (mode != _P_DETACH && (!child.remember () || !child.attach ())) { /* FIXME: Child in strange state now */ CloseHandle (pi.hProcess); ForceCloseHandle (pi.hThread); res = -1; __leave; } } /* Start the child running */ if (c_flags & CREATE_SUSPENDED) { /* Inject a non-inheritable wr_proc_pipe handle into child so that we can accurately track when the child exits without keeping this process waiting around for it to exit. */ if (!iscygwin ()) DuplicateHandle (GetCurrentProcess (), wr_proc_pipe, pi.hProcess, NULL, 0, false, DUPLICATE_SAME_ACCESS); ResumeThread (pi.hThread); if (iscygwin ()) strace.write_childpid (pi.dwProcessId); } ForceCloseHandle (pi.hThread); sigproc_printf ("spawned windows pid %d", pi.dwProcessId); bool synced; if ((mode == _P_DETACH || mode == _P_NOWAIT) && !iscygwin ()) synced = false; else /* Just mark a non-cygwin process as 'synced'. We will still eventually wait for it to exit in maybe_set_exit_code_from_windows(). */ synced = iscygwin () ? sync (pi.dwProcessId, pi.hProcess, INFINITE) : true; switch (mode) { case _P_OVERLAY: myself.hProcess = pi.hProcess; if (!synced) { if (!proc_retry (pi.hProcess)) { looped++; goto loop; } close_all_files (true); } else { if (iscygwin ()) close_all_files (true); if (!my_wr_proc_pipe && WaitForSingleObject (pi.hProcess, 0) == WAIT_TIMEOUT) wait_for_myself (); } if (sem) __posix_spawn_sem_release (sem, 0); if (term_spawn_worker.need_cleanup ()) { LONG prev_sigExeced = sigExeced; while (WaitForSingleObject (pi.hProcess, 100) == WAIT_TIMEOUT) /* If child process does not exit in predetermined time period, the process does not seem to be terminated by the signal sigExeced. Therefore, clear sigExeced here. */ prev_sigExeced = InterlockedCompareExchange (&sigExeced, 0, prev_sigExeced); term_spawn_worker.cleanup (); term_spawn_worker.close_handle_set (); } /* Make sure that ctrl_c_handler() is not on going. Calling init_console_handler(false) locks until returning from ctrl_c_handler(). This insures that setting sigExeced on Ctrl-C key has been completed. */ init_console_handler (false); myself.exit (EXITCODE_NOSET); break; case _P_WAIT: case _P_SYSTEM: system_call.arm (); if (waitpid (cygpid, &res, 0) != cygpid) res = -1; term_spawn_worker.cleanup (); break; case _P_DETACH: res = 0; /* Lost all memory of this child. */ break; case _P_NOWAIT: case _P_NOWAITO: case _P_VFORK: res = cygpid; break; default: break; } } __except (NO_ERROR) { if (get_errno () == ENOMEM) set_errno (E2BIG); else set_errno (EFAULT); res = -1; } __endtry term_spawn_worker.close_handle_set (); this->cleanup (); if (envblock) free (envblock); return (int) res; } extern "C" int cwait (int *result, int pid, int) { return waitpid (pid, result, 0); } /* * Helper function for spawn runtime calls. * Doesn't search the path. */ extern "C" int spawnve (int mode, const char *path, const char *const *argv, const char *const *envp) { static char *const empty_env[] = { NULL }; int ret; syscall_printf ("spawnve (%s, %s, %p)", path, argv[0], envp); if (!envp) envp = empty_env; switch (_P_MODE (mode)) { case _P_OVERLAY: ch_spawn.worker (path, argv, envp, mode); /* Errno should be set by worker. */ ret = -1; break; case _P_VFORK: case _P_NOWAIT: case _P_NOWAITO: case _P_WAIT: case _P_DETACH: case _P_SYSTEM: ret = ch_spawn.worker (path, argv, envp, mode); break; default: set_errno (EINVAL); ret = -1; break; } return ret; } /* * spawn functions as implemented in the MS runtime library. * Most of these based on (and copied from) newlib/libc/posix/execXX.c */ extern "C" int spawnl (int mode, const char *path, const char *arg0, ...) { int i; va_list args; const char *argv[256]; va_start (args, arg0); argv[0] = arg0; i = 1; do argv[i] = va_arg (args, const char *); while (argv[i++] != NULL); va_end (args); return spawnve (mode, path, (char * const *) argv, environ); } extern "C" int spawnle (int mode, const char *path, const char *arg0, ...) { int i; va_list args; const char * const *envp; const char *argv[256]; va_start (args, arg0); argv[0] = arg0; i = 1; do argv[i] = va_arg (args, const char *); while (argv[i++] != NULL); envp = va_arg (args, const char * const *); va_end (args); return spawnve (mode, path, (char * const *) argv, (char * const *) envp); } extern "C" int spawnlp (int mode, const char *file, const char *arg0, ...) { int i; va_list args; const char *argv[256]; path_conv buf; va_start (args, arg0); argv[0] = arg0; i = 1; do argv[i] = va_arg (args, const char *); while (argv[i++] != NULL); va_end (args); return spawnve (mode | _P_PATH_TYPE_EXEC, find_exec (file, buf), (char * const *) argv, environ); } extern "C" int spawnlpe (int mode, const char *file, const char *arg0, ...) { int i; va_list args; const char * const *envp; const char *argv[256]; path_conv buf; va_start (args, arg0); argv[0] = arg0; i = 1; do argv[i] = va_arg (args, const char *); while (argv[i++] != NULL); envp = va_arg (args, const char * const *); va_end (args); return spawnve (mode | _P_PATH_TYPE_EXEC, find_exec (file, buf), (char * const *) argv, envp); } extern "C" int spawnv (int mode, const char *path, const char * const *argv) { return spawnve (mode, path, argv, environ); } extern "C" int spawnvp (int mode, const char *file, const char * const *argv) { path_conv buf; return spawnve (mode | _P_PATH_TYPE_EXEC, find_exec (file, buf, "PATH", FE_NNF) ?: "", argv, environ); } extern "C" int spawnvpe (int mode, const char *file, const char * const *argv, const char * const *envp) { path_conv buf; return spawnve (mode | _P_PATH_TYPE_EXEC, find_exec (file, buf, "PATH", FE_NNF) ?: "", argv, envp); } int av::setup (const char *prog_arg, path_conv& real_path, const char *ext, int ac_in, const char *const *av_in, bool p_type_exec) { const char *p; bool exeext = ascii_strcasematch (ext, ".exe"); new (this) av (ac_in, av_in); if (!argc) { set_errno (E2BIG); return -1; } if ((exeext && real_path.iscygexec ()) || ascii_strcasematch (ext, ".bat") || (!*ext && ((p = ext - 4) > real_path.get_win32 ()) && (ascii_strcasematch (p, ".bat") || ascii_strcasematch (p, ".cmd") || ascii_strcasematch (p, ".btm")))) /* no extra checks needed */; else while (1) { char *pgm = NULL; char *arg1 = NULL; char *ptr, *buf; OBJECT_ATTRIBUTES attr; IO_STATUS_BLOCK io; HANDLE h; NTSTATUS status; LARGE_INTEGER size; status = NtOpenFile (&h, SYNCHRONIZE | GENERIC_READ, real_path.get_object_attr (attr, sec_none_nih), &io, FILE_SHARE_VALID_FLAGS, FILE_SYNCHRONOUS_IO_NONALERT | FILE_OPEN_FOR_BACKUP_INTENT | FILE_NON_DIRECTORY_FILE); if (status == STATUS_IO_REPARSE_TAG_NOT_HANDLED) { /* This is most likely an app execution alias (such as the Windows Store version of Python, i.e. not a Cygwin program */ real_path.set_cygexec (false); break; } if (!NT_SUCCESS (status)) { /* File is not readable? Doesn't mean it's not executable. Test for executability and if so, just assume the file is a cygwin executable and go ahead. */ if (status == STATUS_ACCESS_DENIED && real_path.has_acls () && check_file_access (real_path, X_OK, true) == 0) { real_path.set_cygexec (true); break; } SetLastError (RtlNtStatusToDosError (status)); goto err; } if (!GetFileSizeEx (h, &size)) { NtClose (h); goto err; } if (size.QuadPart > (LONGLONG) wincap.allocation_granularity ()) size.LowPart = wincap.allocation_granularity (); HANDLE hm = CreateFileMapping (h, &sec_none_nih, PAGE_READONLY, 0, 0, NULL); NtClose (h); if (!hm) { /* ERROR_FILE_INVALID indicates very likely an empty file. */ if (GetLastError () == ERROR_FILE_INVALID) { debug_printf ("zero length file, treat as script."); goto just_shell; } goto err; } /* Try to map the first 64K of the image. That's enough for the local tests, and it's enough for hook_or_detect_cygwin to compute the IAT address. */ buf = (char *) MapViewOfFile (hm, FILE_MAP_READ, 0, 0, size.LowPart); if (!buf) { CloseHandle (hm); goto err; } { __try { if (buf[0] == 'M' && buf[1] == 'Z') { WORD subsys; unsigned off = (unsigned char) buf[0x18] | (((unsigned char) buf[0x19]) << 8); win16_exe = off < sizeof (IMAGE_DOS_HEADER); if (!win16_exe) real_path.set_cygexec (hook_or_detect_cygwin (buf, NULL, subsys, hm)); else real_path.set_cygexec (false); UnmapViewOfFile (buf); CloseHandle (hm); break; } } __except (NO_ERROR) { UnmapViewOfFile (buf); CloseHandle (hm); real_path.set_cygexec (false); break; } __endtry } CloseHandle (hm); debug_printf ("%s is possibly a script", real_path.get_win32 ()); ptr = buf; if (*ptr++ == '#' && *ptr++ == '!') { ptr += strspn (ptr, " \t"); size_t len = strcspn (ptr, "\r\n"); while (ptr[len - 1] == ' ' || ptr[len - 1] == '\t') len--; if (len) { char *namebuf = (char *) alloca (len + 1); memcpy (namebuf, ptr, len); namebuf[len] = '\0'; for (ptr = pgm = namebuf; *ptr; ptr++) if (!arg1 && (*ptr == ' ' || *ptr == '\t')) { /* Null terminate the initial command and step over any additional white space. If we've hit the end of the line, exit the loop. Otherwise, we've found the first argument. Position the current pointer on the last known white space. */ *ptr = '\0'; char *newptr = ptr + 1; newptr += strspn (newptr, " \t"); if (!*newptr) break; arg1 = newptr; ptr = newptr - 1; } } } UnmapViewOfFile (buf); just_shell: /* Check if script is executable. Otherwise we start non-executable scripts successfully, which is incorrect behaviour. */ if (real_path.has_acls () && check_file_access (real_path, X_OK, true) < 0) return -1; /* errno is already set. */ if (!pgm) { if (!p_type_exec) { /* Not called from exec[lv]p. Don't try to treat as script. */ debug_printf ("%s is not a valid executable", real_path.get_win32 ()); set_errno (ENOEXEC); return -1; } pgm = (char *) "/bin/sh"; arg1 = NULL; } /* Replace argv[0] with the full path to the script if this is the first time through the loop. */ replace0_maybe (prog_arg); /* pointers: * pgm interpreter name * arg1 optional string */ if (arg1) unshift (arg1); find_exec (pgm, real_path, "PATH", FE_NADA, &ext); unshift (real_path.get_posix ()); } if (real_path.iscygexec ()) dup_all (); return 0; err: __seterrno (); return -1; } /* The following __posix_spawn_* functions are called from newlib's posix_spawn implementation. The original code in newlib has been taken from FreeBSD, and the core code relies on specific, non-portable behaviour of vfork(2). Our replacement implementation uses a semaphore to synchronize parent and child process. Note: __posix_spawn_fork in fork.cc is part of the set. */ /* Create an inheritable semaphore. Set it to 0 (== non-signalled), so the parent can wait on the semaphore immediately. */ extern "C" int __posix_spawn_sem_create (void **semp) { HANDLE sem; OBJECT_ATTRIBUTES attr; NTSTATUS status; if (!semp) return EINVAL; InitializeObjectAttributes (&attr, NULL, OBJ_INHERIT, NULL, NULL); status = NtCreateSemaphore (&sem, SEMAPHORE_ALL_ACCESS, &attr, 0, INT_MAX); if (!NT_SUCCESS (status)) return geterrno_from_nt_status (status); *semp = sem; return 0; } /* Signal the semaphore. "error" should be 0 if all went fine and the exec'd child process is up and running, a useful POSIX error code otherwise. After releasing the semaphore, the value of the semaphore reflects the error code + 1. Thus, after WFMO in__posix_spawn_sem_wait_and_close, querying the value of the semaphore returns either 0 if all went well, or a value > 0 equivalent to the POSIX error code. */ extern "C" void __posix_spawn_sem_release (void *sem, int error) { ReleaseSemaphore (sem, error + 1, NULL); } /* Helper to check the semaphore value. */ static inline int __posix_spawn_sem_query (void *sem) { SEMAPHORE_BASIC_INFORMATION sbi; NtQuerySemaphore (sem, SemaphoreBasicInformation, &sbi, sizeof sbi, NULL); return sbi.CurrentCount; } /* Called from parent to wait for fork/exec completion. We're waiting for the semaphore as well as the child's process handle, so even if the child crashes without signalling the semaphore, we won't wait infinitely. */ extern "C" int __posix_spawn_sem_wait_and_close (void *sem, void *proc) { int ret = 0; HANDLE w4[2] = { sem, proc }; switch (WaitForMultipleObjects (2, w4, FALSE, INFINITE)) { case WAIT_OBJECT_0: ret = __posix_spawn_sem_query (sem); break; case WAIT_OBJECT_0 + 1: /* If we return here due to the child process dying, the semaphore is very likely not signalled. Check this here and return a valid error code. */ ret = __posix_spawn_sem_query (sem); if (ret == 0) ret = ECHILD; break; default: ret = geterrno_from_win_error (); break; } CloseHandle (sem); return ret; } /* Replacement for execve/execvpe, called from forked child in newlib's posix_spawn. The relevant difference is the additional semaphore so the worker method (which is not supposed to return on success) can signal the semaphore after sync'ing with the exec'd child. */ extern "C" int __posix_spawn_execvpe (const char *path, char * const *argv, char *const *envp, HANDLE sem, int use_env_path) { path_conv buf; static char *const empty_env[] = { NULL }; if (!envp) envp = empty_env; ch_spawn.set_sem (sem); ch_spawn.worker (use_env_path ? (find_exec (path, buf, "PATH", FE_NNF) ?: "") : path, argv, envp, _P_OVERLAY); __posix_spawn_sem_release (sem, errno); return -1; }