1#[cfg(target_os = "vxworks")]
2use libc::RTP_ID as pid_t;
3#[cfg(not(target_os = "vxworks"))]
4use libc::{c_int, pid_t};
5#[cfg(not(any(
6 target_os = "vxworks",
7 target_os = "l4re",
8 target_os = "tvos",
9 target_os = "watchos",
10)))]
11use libc::{gid_t, uid_t};
12
13use super::common::*;
14use crate::io::{self, Error, ErrorKind};
15use crate::num::NonZero;
16use crate::sys::cvt;
17#[cfg(target_os = "linux")]
18use crate::sys::pal::linux::pidfd::PidFd;
19use crate::{fmt, mem, sys};
20
21cfg_if::cfg_if! {
22 if #[cfg(target_os = "nto")] {
23 use crate::thread;
24 use libc::{c_char, posix_spawn_file_actions_t, posix_spawnattr_t};
25 use crate::time::Duration;
26 use crate::sync::LazyLock;
27 fn get_clock_resolution() -> Duration {
30 static MIN_DELAY: LazyLock<Duration, fn() -> Duration> = LazyLock::new(|| {
31 let mut mindelay = libc::timespec { tv_sec: 0, tv_nsec: 0 };
32 if unsafe { libc::clock_getres(libc::CLOCK_MONOTONIC, &mut mindelay) } == 0
33 {
34 Duration::from_nanos(mindelay.tv_nsec as u64)
35 } else {
36 Duration::from_millis(1)
37 }
38 });
39 *MIN_DELAY
40 }
41 const MIN_FORKSPAWN_SLEEP: Duration = Duration::from_nanos(1);
43 const MAX_FORKSPAWN_SLEEP: Duration = Duration::from_millis(1000);
45 }
46}
47
48impl Command {
53 pub fn spawn(
54 &mut self,
55 default: Stdio,
56 needs_stdin: bool,
57 ) -> io::Result<(Process, StdioPipes)> {
58 const CLOEXEC_MSG_FOOTER: [u8; 4] = *b"NOEX";
59
60 let envp = self.capture_env();
61
62 if self.saw_nul() {
63 return Err(io::const_error!(
64 ErrorKind::InvalidInput,
65 "nul byte found in provided data",
66 ));
67 }
68
69 let (ours, theirs) = self.setup_io(default, needs_stdin)?;
70
71 if let Some(ret) = self.posix_spawn(&theirs, envp.as_ref())? {
72 return Ok((ret, ours));
73 }
74
75 #[cfg(target_os = "linux")]
76 let (input, output) = sys::net::Socket::new_pair(libc::AF_UNIX, libc::SOCK_SEQPACKET)?;
77
78 #[cfg(not(target_os = "linux"))]
79 let (input, output) = sys::pipe::anon_pipe()?;
80
81 let env_lock = sys::os::env_read_lock();
92 let pid = unsafe { self.do_fork()? };
93
94 if pid == 0 {
95 crate::panic::always_abort();
96 mem::forget(env_lock); drop(input);
98 #[cfg(target_os = "linux")]
99 if self.get_create_pidfd() {
100 self.send_pidfd(&output);
101 }
102 let Err(err) = unsafe { self.do_exec(theirs, envp.as_ref()) };
103 let errno = err.raw_os_error().unwrap_or(libc::EINVAL) as u32;
104 let errno = errno.to_be_bytes();
105 let bytes = [
106 errno[0],
107 errno[1],
108 errno[2],
109 errno[3],
110 CLOEXEC_MSG_FOOTER[0],
111 CLOEXEC_MSG_FOOTER[1],
112 CLOEXEC_MSG_FOOTER[2],
113 CLOEXEC_MSG_FOOTER[3],
114 ];
115 rtassert!(output.write(&bytes).is_ok());
119 unsafe { libc::_exit(1) }
120 }
121
122 drop(env_lock);
123 drop(output);
124
125 #[cfg(target_os = "linux")]
126 let pidfd = if self.get_create_pidfd() { self.recv_pidfd(&input) } else { -1 };
127
128 #[cfg(not(target_os = "linux"))]
129 let pidfd = -1;
130
131 let mut p = unsafe { Process::new(pid, pidfd) };
133 let mut bytes = [0; 8];
134
135 loop {
137 match input.read(&mut bytes) {
138 Ok(0) => return Ok((p, ours)),
139 Ok(8) => {
140 let (errno, footer) = bytes.split_at(4);
141 assert_eq!(
142 CLOEXEC_MSG_FOOTER, footer,
143 "Validation on the CLOEXEC pipe failed: {:?}",
144 bytes
145 );
146 let errno = i32::from_be_bytes(errno.try_into().unwrap());
147 assert!(p.wait().is_ok(), "wait() should either return Ok or panic");
148 return Err(Error::from_raw_os_error(errno));
149 }
150 Err(ref e) if e.is_interrupted() => {}
151 Err(e) => {
152 assert!(p.wait().is_ok(), "wait() should either return Ok or panic");
153 panic!("the CLOEXEC pipe failed: {e:?}")
154 }
155 Ok(..) => {
156 assert!(p.wait().is_ok(), "wait() should either return Ok or panic");
159 panic!("short read on the CLOEXEC pipe")
160 }
161 }
162 }
163 }
164
165 pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
166 let (proc, pipes) = self.spawn(Stdio::MakePipe, false)?;
167 crate::sys_common::process::wait_with_output(proc, pipes)
168 }
169
170 #[cfg(any(target_os = "tvos", target_os = "watchos"))]
177 const ERR_APPLE_TV_WATCH_NO_FORK_EXEC: Error = io::const_error!(
178 ErrorKind::Unsupported,
179 "`fork`+`exec`-based process spawning is not supported on this target",
180 );
181
182 #[cfg(any(target_os = "tvos", target_os = "watchos"))]
183 unsafe fn do_fork(&mut self) -> Result<pid_t, io::Error> {
184 return Err(Self::ERR_APPLE_TV_WATCH_NO_FORK_EXEC);
185 }
186
187 #[cfg(not(any(target_os = "watchos", target_os = "tvos", target_os = "nto")))]
190 unsafe fn do_fork(&mut self) -> Result<pid_t, io::Error> {
191 cvt(libc::fork())
192 }
193
194 #[cfg(target_os = "nto")]
199 unsafe fn do_fork(&mut self) -> Result<pid_t, io::Error> {
200 use crate::sys::os::errno;
201
202 let mut delay = MIN_FORKSPAWN_SLEEP;
203
204 loop {
205 let r = libc::fork();
206 if r == -1 as libc::pid_t && errno() as libc::c_int == libc::EBADF {
207 if delay < get_clock_resolution() {
208 thread::yield_now();
211 } else if delay < MAX_FORKSPAWN_SLEEP {
212 thread::sleep(delay);
213 } else {
214 return Err(io::const_error!(
215 ErrorKind::WouldBlock,
216 "forking returned EBADF too often",
217 ));
218 }
219 delay *= 2;
220 continue;
221 } else {
222 return cvt(r);
223 }
224 }
225 }
226
227 pub fn exec(&mut self, default: Stdio) -> io::Error {
228 let envp = self.capture_env();
229
230 if self.saw_nul() {
231 return io::const_error!(ErrorKind::InvalidInput, "nul byte found in provided data");
232 }
233
234 match self.setup_io(default, true) {
235 Ok((_, theirs)) => {
236 unsafe {
237 let _lock = sys::os::env_read_lock();
241
242 let Err(e) = self.do_exec(theirs, envp.as_ref());
243 e
244 }
245 }
246 Err(e) => e,
247 }
248 }
249
250 #[cfg(not(any(target_os = "tvos", target_os = "watchos")))]
281 unsafe fn do_exec(
282 &mut self,
283 stdio: ChildPipes,
284 maybe_envp: Option<&CStringArray>,
285 ) -> Result<!, io::Error> {
286 use crate::sys::{self, cvt_r};
287
288 if let Some(fd) = stdio.stdin.fd() {
289 cvt_r(|| libc::dup2(fd, libc::STDIN_FILENO))?;
290 }
291 if let Some(fd) = stdio.stdout.fd() {
292 cvt_r(|| libc::dup2(fd, libc::STDOUT_FILENO))?;
293 }
294 if let Some(fd) = stdio.stderr.fd() {
295 cvt_r(|| libc::dup2(fd, libc::STDERR_FILENO))?;
296 }
297
298 #[cfg(not(target_os = "l4re"))]
299 {
300 if let Some(_g) = self.get_groups() {
301 #[cfg(not(target_os = "redox"))]
303 cvt(libc::setgroups(_g.len().try_into().unwrap(), _g.as_ptr()))?;
304 }
305 if let Some(u) = self.get_gid() {
306 cvt(libc::setgid(u as gid_t))?;
307 }
308 if let Some(u) = self.get_uid() {
309 #[cfg(not(target_os = "redox"))]
317 if self.get_groups().is_none() {
318 let res = cvt(libc::setgroups(0, crate::ptr::null()));
319 if let Err(e) = res {
320 if e.raw_os_error() != Some(libc::EPERM) {
324 return Err(e.into());
325 }
326 }
327 }
328 cvt(libc::setuid(u as uid_t))?;
329 }
330 }
331 if let Some(cwd) = self.get_cwd() {
332 cvt(libc::chdir(cwd.as_ptr()))?;
333 }
334
335 if let Some(pgroup) = self.get_pgroup() {
336 cvt(libc::setpgid(0, pgroup))?;
337 }
338
339 #[cfg(not(target_os = "emscripten"))]
341 {
342 if !crate::sys::pal::on_broken_pipe_flag_used() {
350 #[cfg(target_os = "android")] {
352 let mut action: libc::sigaction = mem::zeroed();
353 action.sa_sigaction = libc::SIG_DFL;
354 cvt(libc::sigaction(libc::SIGPIPE, &action, crate::ptr::null_mut()))?;
355 }
356 #[cfg(not(target_os = "android"))]
357 {
358 let ret = sys::signal(libc::SIGPIPE, libc::SIG_DFL);
359 if ret == libc::SIG_ERR {
360 return Err(io::Error::last_os_error());
361 }
362 }
363 #[cfg(target_os = "hurd")]
364 {
365 let ret = sys::signal(libc::SIGLOST, libc::SIG_DFL);
366 if ret == libc::SIG_ERR {
367 return Err(io::Error::last_os_error());
368 }
369 }
370 }
371 }
372
373 for callback in self.get_closures().iter_mut() {
374 callback()?;
375 }
376
377 let mut _reset = None;
383 if let Some(envp) = maybe_envp {
384 struct Reset(*const *const libc::c_char);
385
386 impl Drop for Reset {
387 fn drop(&mut self) {
388 unsafe {
389 *sys::os::environ() = self.0;
390 }
391 }
392 }
393
394 _reset = Some(Reset(*sys::os::environ()));
395 *sys::os::environ() = envp.as_ptr();
396 }
397
398 libc::execvp(self.get_program_cstr().as_ptr(), self.get_argv().as_ptr());
399 Err(io::Error::last_os_error())
400 }
401
402 #[cfg(any(target_os = "tvos", target_os = "watchos"))]
403 unsafe fn do_exec(
404 &mut self,
405 _stdio: ChildPipes,
406 _maybe_envp: Option<&CStringArray>,
407 ) -> Result<!, io::Error> {
408 return Err(Self::ERR_APPLE_TV_WATCH_NO_FORK_EXEC);
409 }
410
411 #[cfg(not(any(
412 target_os = "freebsd",
413 target_os = "illumos",
414 all(target_os = "linux", target_env = "gnu"),
415 all(target_os = "linux", target_env = "musl"),
416 target_os = "nto",
417 target_vendor = "apple",
418 )))]
419 fn posix_spawn(
420 &mut self,
421 _: &ChildPipes,
422 _: Option<&CStringArray>,
423 ) -> io::Result<Option<Process>> {
424 Ok(None)
425 }
426
427 #[cfg(any(
430 target_os = "freebsd",
431 target_os = "illumos",
432 all(target_os = "linux", target_env = "gnu"),
433 all(target_os = "linux", target_env = "musl"),
434 target_os = "nto",
435 target_vendor = "apple",
436 ))]
437 fn posix_spawn(
438 &mut self,
439 stdio: &ChildPipes,
440 envp: Option<&CStringArray>,
441 ) -> io::Result<Option<Process>> {
442 #[cfg(target_os = "linux")]
443 use core::sync::atomic::{AtomicU8, Ordering};
444
445 use crate::mem::MaybeUninit;
446 use crate::sys::{self, cvt_nz, on_broken_pipe_flag_used};
447
448 if self.get_gid().is_some()
449 || self.get_uid().is_some()
450 || (self.env_saw_path() && !self.program_is_path())
451 || !self.get_closures().is_empty()
452 || self.get_groups().is_some()
453 {
454 return Ok(None);
455 }
456
457 cfg_if::cfg_if! {
458 if #[cfg(target_os = "linux")] {
459 use crate::sys::weak::weak;
460
461 weak!(
462 fn pidfd_spawnp(
463 pidfd: *mut libc::c_int,
464 path: *const libc::c_char,
465 file_actions: *const libc::posix_spawn_file_actions_t,
466 attrp: *const libc::posix_spawnattr_t,
467 argv: *const *mut libc::c_char,
468 envp: *const *mut libc::c_char,
469 ) -> libc::c_int;
470 );
471
472 weak!(
473 fn pidfd_getpid(pidfd: libc::c_int) -> libc::c_int;
474 );
475
476 static PIDFD_SUPPORTED: AtomicU8 = AtomicU8::new(0);
477 const UNKNOWN: u8 = 0;
478 const SPAWN: u8 = 1;
479 const FORK_EXEC: u8 = 2;
481 const NO: u8 = 3;
484
485 if self.get_create_pidfd() {
486 let mut support = PIDFD_SUPPORTED.load(Ordering::Relaxed);
487 if support == FORK_EXEC {
488 return Ok(None);
489 }
490 if support == UNKNOWN {
491 support = NO;
492 let our_pid = crate::process::id();
493 let pidfd = cvt(unsafe { libc::syscall(libc::SYS_pidfd_open, our_pid, 0) } as c_int);
494 match pidfd {
495 Ok(pidfd) => {
496 support = FORK_EXEC;
497 if let Some(Ok(pid)) = pidfd_getpid.get().map(|f| cvt(unsafe { f(pidfd) } as i32)) {
498 if pidfd_spawnp.get().is_some() && pid as u32 == our_pid {
499 support = SPAWN
500 }
501 }
502 unsafe { libc::close(pidfd) };
503 }
504 Err(e) if e.raw_os_error() == Some(libc::EMFILE) => {
505 return Err(e)
508 }
509 _ => {}
510 }
511 PIDFD_SUPPORTED.store(support, Ordering::Relaxed);
512 if support == FORK_EXEC {
513 return Ok(None);
514 }
515 }
516 core::assert_matches::debug_assert_matches!(support, SPAWN | NO);
517 }
518 } else {
519 if self.get_create_pidfd() {
520 unreachable!("only implemented on linux")
521 }
522 }
523 }
524
525 #[cfg(all(target_os = "linux", target_env = "gnu"))]
527 {
528 if let Some(version) = sys::os::glibc_version() {
529 if version < (2, 24) {
530 return Ok(None);
531 }
532 } else {
533 return Ok(None);
534 }
535 }
536
537 #[cfg(target_os = "nto")]
542 unsafe fn retrying_libc_posix_spawnp(
543 pid: *mut pid_t,
544 file: *const c_char,
545 file_actions: *const posix_spawn_file_actions_t,
546 attrp: *const posix_spawnattr_t,
547 argv: *const *mut c_char,
548 envp: *const *mut c_char,
549 ) -> io::Result<i32> {
550 let mut delay = MIN_FORKSPAWN_SLEEP;
551 loop {
552 match libc::posix_spawnp(pid, file, file_actions, attrp, argv, envp) {
553 libc::EBADF => {
554 if delay < get_clock_resolution() {
555 thread::yield_now();
558 } else if delay < MAX_FORKSPAWN_SLEEP {
559 thread::sleep(delay);
560 } else {
561 return Err(io::const_error!(
562 ErrorKind::WouldBlock,
563 "posix_spawnp returned EBADF too often",
564 ));
565 }
566 delay *= 2;
567 continue;
568 }
569 r => {
570 return Ok(r);
571 }
572 }
573 }
574 }
575
576 type PosixSpawnAddChdirFn = unsafe extern "C" fn(
577 *mut libc::posix_spawn_file_actions_t,
578 *const libc::c_char,
579 ) -> libc::c_int;
580
581 #[cfg(not(all(target_os = "linux", target_env = "musl")))]
588 fn get_posix_spawn_addchdir() -> Option<PosixSpawnAddChdirFn> {
589 use crate::sys::weak::weak;
590
591 weak!(
596 fn posix_spawn_file_actions_addchdir_np(
597 file_actions: *mut libc::posix_spawn_file_actions_t,
598 path: *const libc::c_char,
599 ) -> libc::c_int;
600 );
601
602 weak!(
603 fn posix_spawn_file_actions_addchdir(
604 file_actions: *mut libc::posix_spawn_file_actions_t,
605 path: *const libc::c_char,
606 ) -> libc::c_int;
607 );
608
609 posix_spawn_file_actions_addchdir_np
610 .get()
611 .or_else(|| posix_spawn_file_actions_addchdir.get())
612 }
613
614 #[cfg(all(target_os = "linux", target_env = "musl"))]
622 fn get_posix_spawn_addchdir() -> Option<PosixSpawnAddChdirFn> {
623 Some(libc::posix_spawn_file_actions_addchdir_np)
625 }
626
627 let addchdir = match self.get_cwd() {
628 Some(cwd) => {
629 if cfg!(target_vendor = "apple") {
630 if self.get_program_kind() == ProgramKind::Relative {
636 return Ok(None);
637 }
638 }
639 match get_posix_spawn_addchdir() {
643 Some(f) => Some((f, cwd)),
644 None => return Ok(None),
645 }
646 }
647 None => None,
648 };
649
650 let pgroup = self.get_pgroup();
651
652 struct PosixSpawnFileActions<'a>(&'a mut MaybeUninit<libc::posix_spawn_file_actions_t>);
653
654 impl Drop for PosixSpawnFileActions<'_> {
655 fn drop(&mut self) {
656 unsafe {
657 libc::posix_spawn_file_actions_destroy(self.0.as_mut_ptr());
658 }
659 }
660 }
661
662 struct PosixSpawnattr<'a>(&'a mut MaybeUninit<libc::posix_spawnattr_t>);
663
664 impl Drop for PosixSpawnattr<'_> {
665 fn drop(&mut self) {
666 unsafe {
667 libc::posix_spawnattr_destroy(self.0.as_mut_ptr());
668 }
669 }
670 }
671
672 unsafe {
673 let mut attrs = MaybeUninit::uninit();
674 cvt_nz(libc::posix_spawnattr_init(attrs.as_mut_ptr()))?;
675 let attrs = PosixSpawnattr(&mut attrs);
676
677 let mut flags = 0;
678
679 let mut file_actions = MaybeUninit::uninit();
680 cvt_nz(libc::posix_spawn_file_actions_init(file_actions.as_mut_ptr()))?;
681 let file_actions = PosixSpawnFileActions(&mut file_actions);
682
683 if let Some(fd) = stdio.stdin.fd() {
684 cvt_nz(libc::posix_spawn_file_actions_adddup2(
685 file_actions.0.as_mut_ptr(),
686 fd,
687 libc::STDIN_FILENO,
688 ))?;
689 }
690 if let Some(fd) = stdio.stdout.fd() {
691 cvt_nz(libc::posix_spawn_file_actions_adddup2(
692 file_actions.0.as_mut_ptr(),
693 fd,
694 libc::STDOUT_FILENO,
695 ))?;
696 }
697 if let Some(fd) = stdio.stderr.fd() {
698 cvt_nz(libc::posix_spawn_file_actions_adddup2(
699 file_actions.0.as_mut_ptr(),
700 fd,
701 libc::STDERR_FILENO,
702 ))?;
703 }
704 if let Some((f, cwd)) = addchdir {
705 cvt_nz(f(file_actions.0.as_mut_ptr(), cwd.as_ptr()))?;
706 }
707
708 if let Some(pgroup) = pgroup {
709 flags |= libc::POSIX_SPAWN_SETPGROUP;
710 cvt_nz(libc::posix_spawnattr_setpgroup(attrs.0.as_mut_ptr(), pgroup))?;
711 }
712
713 if !on_broken_pipe_flag_used() {
721 let mut default_set = MaybeUninit::<libc::sigset_t>::uninit();
722 cvt(sigemptyset(default_set.as_mut_ptr()))?;
723 cvt(sigaddset(default_set.as_mut_ptr(), libc::SIGPIPE))?;
724 #[cfg(target_os = "hurd")]
725 {
726 cvt(sigaddset(default_set.as_mut_ptr(), libc::SIGLOST))?;
727 }
728 cvt_nz(libc::posix_spawnattr_setsigdefault(
729 attrs.0.as_mut_ptr(),
730 default_set.as_ptr(),
731 ))?;
732 flags |= libc::POSIX_SPAWN_SETSIGDEF;
733 }
734
735 cvt_nz(libc::posix_spawnattr_setflags(attrs.0.as_mut_ptr(), flags as _))?;
736
737 let _env_lock = sys::os::env_read_lock();
739 let envp = envp.map(|c| c.as_ptr()).unwrap_or_else(|| *sys::os::environ() as *const _);
740
741 #[cfg(not(target_os = "nto"))]
742 let spawn_fn = libc::posix_spawnp;
743 #[cfg(target_os = "nto")]
744 let spawn_fn = retrying_libc_posix_spawnp;
745
746 #[cfg(target_os = "linux")]
747 if self.get_create_pidfd() && PIDFD_SUPPORTED.load(Ordering::Relaxed) == SPAWN {
748 let mut pidfd: libc::c_int = -1;
749 let spawn_res = pidfd_spawnp.get().unwrap()(
750 &mut pidfd,
751 self.get_program_cstr().as_ptr(),
752 file_actions.0.as_ptr(),
753 attrs.0.as_ptr(),
754 self.get_argv().as_ptr() as *const _,
755 envp as *const _,
756 );
757
758 let spawn_res = cvt_nz(spawn_res);
759 if let Err(ref e) = spawn_res
760 && e.raw_os_error() == Some(libc::ENOSYS)
761 {
762 PIDFD_SUPPORTED.store(FORK_EXEC, Ordering::Relaxed);
763 return Ok(None);
764 }
765 spawn_res?;
766
767 let pid = match cvt(pidfd_getpid.get().unwrap()(pidfd)) {
768 Ok(pid) => pid,
769 Err(e) => {
770 libc::close(pidfd);
774 return Err(Error::new(
775 e.kind(),
776 "pidfd_spawnp succeeded but the child's PID could not be obtained",
777 ));
778 }
779 };
780
781 return Ok(Some(Process::new(pid, pidfd)));
782 }
783
784 let mut p = Process::new(0, -1);
786
787 let spawn_res = spawn_fn(
788 &mut p.pid,
789 self.get_program_cstr().as_ptr(),
790 file_actions.0.as_ptr(),
791 attrs.0.as_ptr(),
792 self.get_argv().as_ptr() as *const _,
793 envp as *const _,
794 );
795
796 #[cfg(target_os = "nto")]
797 let spawn_res = spawn_res?;
798
799 cvt_nz(spawn_res)?;
800 Ok(Some(p))
801 }
802 }
803
804 #[cfg(target_os = "linux")]
805 fn send_pidfd(&self, sock: &crate::sys::net::Socket) {
806 use libc::{CMSG_DATA, CMSG_FIRSTHDR, CMSG_LEN, CMSG_SPACE, SCM_RIGHTS, SOL_SOCKET};
807
808 use crate::io::IoSlice;
809 use crate::os::fd::RawFd;
810 use crate::sys::cvt_r;
811
812 unsafe {
813 let child_pid = libc::getpid();
814 let pidfd = libc::syscall(libc::SYS_pidfd_open, child_pid, 0);
816
817 let fds: [c_int; 1] = [pidfd as RawFd];
818
819 const SCM_MSG_LEN: usize = size_of::<[c_int; 1]>();
820
821 #[repr(C)]
822 union Cmsg {
823 buf: [u8; unsafe { CMSG_SPACE(SCM_MSG_LEN as u32) as usize }],
824 _align: libc::cmsghdr,
825 }
826
827 let mut cmsg: Cmsg = mem::zeroed();
828
829 let mut iov = [IoSlice::new(b"")];
831 let mut msg: libc::msghdr = mem::zeroed();
832
833 msg.msg_iov = (&raw mut iov) as *mut _;
834 msg.msg_iovlen = 1;
835
836 if pidfd >= 0 {
838 msg.msg_controllen = size_of_val(&cmsg.buf) as _;
839 msg.msg_control = (&raw mut cmsg.buf) as *mut _;
840
841 let hdr = CMSG_FIRSTHDR((&raw mut msg) as *mut _);
842 (*hdr).cmsg_level = SOL_SOCKET;
843 (*hdr).cmsg_type = SCM_RIGHTS;
844 (*hdr).cmsg_len = CMSG_LEN(SCM_MSG_LEN as _) as _;
845 let data = CMSG_DATA(hdr);
846 crate::ptr::copy_nonoverlapping(
847 fds.as_ptr().cast::<u8>(),
848 data as *mut _,
849 SCM_MSG_LEN,
850 );
851 }
852
853 match cvt_r(|| libc::sendmsg(sock.as_raw(), &msg, 0)) {
856 Ok(0) => {}
857 other => rtabort!("failed to communicate with parent process. {:?}", other),
858 }
859 }
860 }
861
862 #[cfg(target_os = "linux")]
863 fn recv_pidfd(&self, sock: &crate::sys::net::Socket) -> pid_t {
864 use libc::{CMSG_DATA, CMSG_FIRSTHDR, CMSG_LEN, CMSG_SPACE, SCM_RIGHTS, SOL_SOCKET};
865
866 use crate::io::IoSliceMut;
867 use crate::sys::cvt_r;
868
869 unsafe {
870 const SCM_MSG_LEN: usize = size_of::<[c_int; 1]>();
871
872 #[repr(C)]
873 union Cmsg {
874 _buf: [u8; unsafe { CMSG_SPACE(SCM_MSG_LEN as u32) as usize }],
875 _align: libc::cmsghdr,
876 }
877 let mut cmsg: Cmsg = mem::zeroed();
878 let mut iov = [IoSliceMut::new(&mut [])];
880
881 let mut msg: libc::msghdr = mem::zeroed();
882
883 msg.msg_iov = (&raw mut iov) as *mut _;
884 msg.msg_iovlen = 1;
885 msg.msg_controllen = size_of::<Cmsg>() as _;
886 msg.msg_control = (&raw mut cmsg) as *mut _;
887
888 match cvt_r(|| libc::recvmsg(sock.as_raw(), &mut msg, libc::MSG_CMSG_CLOEXEC)) {
889 Err(_) => return -1,
890 Ok(_) => {}
891 }
892
893 let hdr = CMSG_FIRSTHDR((&raw mut msg) as *mut _);
894 if hdr.is_null()
895 || (*hdr).cmsg_level != SOL_SOCKET
896 || (*hdr).cmsg_type != SCM_RIGHTS
897 || (*hdr).cmsg_len != CMSG_LEN(SCM_MSG_LEN as _) as _
898 {
899 return -1;
900 }
901 let data = CMSG_DATA(hdr);
902
903 let mut fds = [-1 as c_int];
904
905 crate::ptr::copy_nonoverlapping(
906 data as *const _,
907 fds.as_mut_ptr().cast::<u8>(),
908 SCM_MSG_LEN,
909 );
910
911 fds[0]
912 }
913 }
914}
915
916pub struct Process {
922 pid: pid_t,
923 status: Option<ExitStatus>,
924 #[cfg(target_os = "linux")]
929 pidfd: Option<PidFd>,
930}
931
932impl Process {
933 #[cfg(target_os = "linux")]
934 unsafe fn new(pid: pid_t, pidfd: pid_t) -> Self {
941 use crate::os::unix::io::FromRawFd;
942 use crate::sys_common::FromInner;
943 let pidfd = (pidfd >= 0).then(|| PidFd::from_inner(sys::fd::FileDesc::from_raw_fd(pidfd)));
945 Process { pid, status: None, pidfd }
946 }
947
948 #[cfg(not(target_os = "linux"))]
949 unsafe fn new(pid: pid_t, _pidfd: pid_t) -> Self {
950 Process { pid, status: None }
951 }
952
953 pub fn id(&self) -> u32 {
954 self.pid as u32
955 }
956
957 pub fn kill(&mut self) -> io::Result<()> {
958 if self.status.is_some() {
962 return Ok(());
963 }
964 #[cfg(target_os = "linux")]
965 if let Some(pid_fd) = self.pidfd.as_ref() {
966 return pid_fd.kill();
968 }
969 cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(drop)
970 }
971
972 pub fn wait(&mut self) -> io::Result<ExitStatus> {
973 use crate::sys::cvt_r;
974 if let Some(status) = self.status {
975 return Ok(status);
976 }
977 #[cfg(target_os = "linux")]
978 if let Some(pid_fd) = self.pidfd.as_ref() {
979 let status = pid_fd.wait()?;
980 self.status = Some(status);
981 return Ok(status);
982 }
983 let mut status = 0 as c_int;
984 cvt_r(|| unsafe { libc::waitpid(self.pid, &mut status, 0) })?;
985 self.status = Some(ExitStatus::new(status));
986 Ok(ExitStatus::new(status))
987 }
988
989 pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
990 if let Some(status) = self.status {
991 return Ok(Some(status));
992 }
993 #[cfg(target_os = "linux")]
994 if let Some(pid_fd) = self.pidfd.as_ref() {
995 let status = pid_fd.try_wait()?;
996 if let Some(status) = status {
997 self.status = Some(status)
998 }
999 return Ok(status);
1000 }
1001 let mut status = 0 as c_int;
1002 let pid = cvt(unsafe { libc::waitpid(self.pid, &mut status, libc::WNOHANG) })?;
1003 if pid == 0 {
1004 Ok(None)
1005 } else {
1006 self.status = Some(ExitStatus::new(status));
1007 Ok(Some(ExitStatus::new(status)))
1008 }
1009 }
1010}
1011
1012#[derive(PartialEq, Eq, Clone, Copy, Default)]
1017pub struct ExitStatus(c_int);
1018
1019impl fmt::Debug for ExitStatus {
1020 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1021 f.debug_tuple("unix_wait_status").field(&self.0).finish()
1022 }
1023}
1024
1025impl ExitStatus {
1026 pub fn new(status: c_int) -> ExitStatus {
1027 ExitStatus(status)
1028 }
1029
1030 #[cfg(target_os = "linux")]
1031 pub fn from_waitid_siginfo(siginfo: libc::siginfo_t) -> ExitStatus {
1032 let status = unsafe { siginfo.si_status() };
1033
1034 match siginfo.si_code {
1035 libc::CLD_EXITED => ExitStatus((status & 0xff) << 8),
1036 libc::CLD_KILLED => ExitStatus(status),
1037 libc::CLD_DUMPED => ExitStatus(status | 0x80),
1038 libc::CLD_CONTINUED => ExitStatus(0xffff),
1039 libc::CLD_STOPPED | libc::CLD_TRAPPED => ExitStatus(((status & 0xff) << 8) | 0x7f),
1040 _ => unreachable!("waitid() should only return the above codes"),
1041 }
1042 }
1043
1044 fn exited(&self) -> bool {
1045 libc::WIFEXITED(self.0)
1046 }
1047
1048 pub fn exit_ok(&self) -> Result<(), ExitStatusError> {
1049 match NonZero::try_from(self.0) {
1055 Ok(failure) => Err(ExitStatusError(failure)),
1056 Err(_) => Ok(()),
1057 }
1058 }
1059
1060 pub fn code(&self) -> Option<i32> {
1061 self.exited().then(|| libc::WEXITSTATUS(self.0))
1062 }
1063
1064 pub fn signal(&self) -> Option<i32> {
1065 libc::WIFSIGNALED(self.0).then(|| libc::WTERMSIG(self.0))
1066 }
1067
1068 pub fn core_dumped(&self) -> bool {
1069 libc::WIFSIGNALED(self.0) && libc::WCOREDUMP(self.0)
1070 }
1071
1072 pub fn stopped_signal(&self) -> Option<i32> {
1073 libc::WIFSTOPPED(self.0).then(|| libc::WSTOPSIG(self.0))
1074 }
1075
1076 pub fn continued(&self) -> bool {
1077 libc::WIFCONTINUED(self.0)
1078 }
1079
1080 pub fn into_raw(&self) -> c_int {
1081 self.0
1082 }
1083}
1084
1085impl From<c_int> for ExitStatus {
1087 fn from(a: c_int) -> ExitStatus {
1088 ExitStatus(a)
1089 }
1090}
1091
1092fn signal_string(signal: i32) -> &'static str {
1099 match signal {
1100 libc::SIGHUP => " (SIGHUP)",
1101 libc::SIGINT => " (SIGINT)",
1102 libc::SIGQUIT => " (SIGQUIT)",
1103 libc::SIGILL => " (SIGILL)",
1104 libc::SIGTRAP => " (SIGTRAP)",
1105 libc::SIGABRT => " (SIGABRT)",
1106 #[cfg(not(target_os = "l4re"))]
1107 libc::SIGBUS => " (SIGBUS)",
1108 libc::SIGFPE => " (SIGFPE)",
1109 libc::SIGKILL => " (SIGKILL)",
1110 #[cfg(not(target_os = "l4re"))]
1111 libc::SIGUSR1 => " (SIGUSR1)",
1112 libc::SIGSEGV => " (SIGSEGV)",
1113 #[cfg(not(target_os = "l4re"))]
1114 libc::SIGUSR2 => " (SIGUSR2)",
1115 libc::SIGPIPE => " (SIGPIPE)",
1116 libc::SIGALRM => " (SIGALRM)",
1117 libc::SIGTERM => " (SIGTERM)",
1118 #[cfg(not(target_os = "l4re"))]
1119 libc::SIGCHLD => " (SIGCHLD)",
1120 #[cfg(not(target_os = "l4re"))]
1121 libc::SIGCONT => " (SIGCONT)",
1122 #[cfg(not(target_os = "l4re"))]
1123 libc::SIGSTOP => " (SIGSTOP)",
1124 #[cfg(not(target_os = "l4re"))]
1125 libc::SIGTSTP => " (SIGTSTP)",
1126 #[cfg(not(target_os = "l4re"))]
1127 libc::SIGTTIN => " (SIGTTIN)",
1128 #[cfg(not(target_os = "l4re"))]
1129 libc::SIGTTOU => " (SIGTTOU)",
1130 #[cfg(not(target_os = "l4re"))]
1131 libc::SIGURG => " (SIGURG)",
1132 #[cfg(not(target_os = "l4re"))]
1133 libc::SIGXCPU => " (SIGXCPU)",
1134 #[cfg(not(any(target_os = "l4re", target_os = "rtems")))]
1135 libc::SIGXFSZ => " (SIGXFSZ)",
1136 #[cfg(not(any(target_os = "l4re", target_os = "rtems")))]
1137 libc::SIGVTALRM => " (SIGVTALRM)",
1138 #[cfg(not(target_os = "l4re"))]
1139 libc::SIGPROF => " (SIGPROF)",
1140 #[cfg(not(any(target_os = "l4re", target_os = "rtems")))]
1141 libc::SIGWINCH => " (SIGWINCH)",
1142 #[cfg(not(any(target_os = "haiku", target_os = "l4re")))]
1143 libc::SIGIO => " (SIGIO)",
1144 #[cfg(target_os = "haiku")]
1145 libc::SIGPOLL => " (SIGPOLL)",
1146 #[cfg(not(target_os = "l4re"))]
1147 libc::SIGSYS => " (SIGSYS)",
1148 #[cfg(all(
1150 target_os = "linux",
1151 any(
1152 target_arch = "x86_64",
1153 target_arch = "x86",
1154 target_arch = "arm",
1155 target_arch = "aarch64"
1156 )
1157 ))]
1158 libc::SIGSTKFLT => " (SIGSTKFLT)",
1159 #[cfg(any(target_os = "linux", target_os = "nto", target_os = "cygwin"))]
1160 libc::SIGPWR => " (SIGPWR)",
1161 #[cfg(any(
1162 target_os = "freebsd",
1163 target_os = "netbsd",
1164 target_os = "openbsd",
1165 target_os = "dragonfly",
1166 target_os = "nto",
1167 target_vendor = "apple",
1168 target_os = "cygwin",
1169 ))]
1170 libc::SIGEMT => " (SIGEMT)",
1171 #[cfg(any(
1172 target_os = "freebsd",
1173 target_os = "netbsd",
1174 target_os = "openbsd",
1175 target_os = "dragonfly",
1176 target_vendor = "apple",
1177 ))]
1178 libc::SIGINFO => " (SIGINFO)",
1179 #[cfg(target_os = "hurd")]
1180 libc::SIGLOST => " (SIGLOST)",
1181 #[cfg(target_os = "freebsd")]
1182 libc::SIGTHR => " (SIGTHR)",
1183 #[cfg(target_os = "freebsd")]
1184 libc::SIGLIBRT => " (SIGLIBRT)",
1185 _ => "",
1186 }
1187}
1188
1189impl fmt::Display for ExitStatus {
1190 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1191 if let Some(code) = self.code() {
1192 write!(f, "exit status: {code}")
1193 } else if let Some(signal) = self.signal() {
1194 let signal_string = signal_string(signal);
1195 if self.core_dumped() {
1196 write!(f, "signal: {signal}{signal_string} (core dumped)")
1197 } else {
1198 write!(f, "signal: {signal}{signal_string}")
1199 }
1200 } else if let Some(signal) = self.stopped_signal() {
1201 let signal_string = signal_string(signal);
1202 write!(f, "stopped (not terminated) by signal: {signal}{signal_string}")
1203 } else if self.continued() {
1204 write!(f, "continued (WIFCONTINUED)")
1205 } else {
1206 write!(f, "unrecognised wait status: {} {:#x}", self.0, self.0)
1207 }
1208 }
1209}
1210
1211#[derive(PartialEq, Eq, Clone, Copy)]
1212pub struct ExitStatusError(NonZero<c_int>);
1213
1214impl Into<ExitStatus> for ExitStatusError {
1215 fn into(self) -> ExitStatus {
1216 ExitStatus(self.0.into())
1217 }
1218}
1219
1220impl fmt::Debug for ExitStatusError {
1221 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1222 f.debug_tuple("unix_wait_status").field(&self.0).finish()
1223 }
1224}
1225
1226impl ExitStatusError {
1227 pub fn code(self) -> Option<NonZero<i32>> {
1228 ExitStatus(self.0.into()).code().map(|st| st.try_into().unwrap())
1229 }
1230}
1231
1232#[cfg(target_os = "linux")]
1233mod linux_child_ext {
1234 use crate::io::ErrorKind;
1235 use crate::os::linux::process as os;
1236 use crate::sys::pal::linux::pidfd as imp;
1237 use crate::sys_common::FromInner;
1238 use crate::{io, mem};
1239
1240 #[unstable(feature = "linux_pidfd", issue = "82971")]
1241 impl crate::os::linux::process::ChildExt for crate::process::Child {
1242 fn pidfd(&self) -> io::Result<&os::PidFd> {
1243 self.handle
1244 .pidfd
1245 .as_ref()
1246 .map(|fd| unsafe { mem::transmute::<&imp::PidFd, &os::PidFd>(fd) })
1248 .ok_or_else(|| io::const_error!(ErrorKind::Uncategorized, "no pidfd was created."))
1249 }
1250
1251 fn into_pidfd(mut self) -> Result<os::PidFd, Self> {
1252 self.handle
1253 .pidfd
1254 .take()
1255 .map(|fd| <os::PidFd as FromInner<imp::PidFd>>::from_inner(fd))
1256 .ok_or_else(|| self)
1257 }
1258 }
1259}
1260
1261#[cfg(test)]
1262mod tests;
1263
1264#[cfg(all(test, target_os = "linux"))]
1266#[path = "unsupported/wait_status.rs"]
1267mod unsupported_wait_status;