diff options
Diffstat (limited to 'ctr-std/src/sys/unix/process/process_unix.rs')
| -rw-r--r-- | ctr-std/src/sys/unix/process/process_unix.rs | 405 |
1 files changed, 0 insertions, 405 deletions
diff --git a/ctr-std/src/sys/unix/process/process_unix.rs b/ctr-std/src/sys/unix/process/process_unix.rs deleted file mode 100644 index 9d6d607..0000000 --- a/ctr-std/src/sys/unix/process/process_unix.rs +++ /dev/null @@ -1,405 +0,0 @@ -// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT -// file at the top-level directory of this distribution and at -// http://rust-lang.org/COPYRIGHT. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -use io::{self, Error, ErrorKind}; -use libc::{self, c_int, gid_t, pid_t, uid_t}; -use ptr; - -use sys::cvt; -use sys::process::process_common::*; - -//////////////////////////////////////////////////////////////////////////////// -// Command -//////////////////////////////////////////////////////////////////////////////// - -impl Command { - pub fn spawn(&mut self, default: Stdio, needs_stdin: bool) - -> io::Result<(Process, StdioPipes)> { - use sys; - - const CLOEXEC_MSG_FOOTER: &'static [u8] = b"NOEX"; - - let envp = self.capture_env(); - - if self.saw_nul() { - return Err(io::Error::new(ErrorKind::InvalidInput, - "nul byte found in provided data")); - } - - let (ours, theirs) = self.setup_io(default, needs_stdin)?; - - if let Some(ret) = self.posix_spawn(&theirs, envp.as_ref())? { - return Ok((ret, ours)) - } - - let (input, output) = sys::pipe::anon_pipe()?; - - let pid = unsafe { - match cvt(libc::fork())? { - 0 => { - drop(input); - let err = self.do_exec(theirs, envp.as_ref()); - let errno = err.raw_os_error().unwrap_or(libc::EINVAL) as u32; - let bytes = [ - (errno >> 24) as u8, - (errno >> 16) as u8, - (errno >> 8) as u8, - (errno >> 0) as u8, - CLOEXEC_MSG_FOOTER[0], CLOEXEC_MSG_FOOTER[1], - CLOEXEC_MSG_FOOTER[2], CLOEXEC_MSG_FOOTER[3] - ]; - // pipe I/O up to PIPE_BUF bytes should be atomic, and then - // we want to be sure we *don't* run at_exit destructors as - // we're being torn down regardless - assert!(output.write(&bytes).is_ok()); - libc::_exit(1) - } - n => n, - } - }; - - let mut p = Process { pid: pid, status: None }; - drop(output); - let mut bytes = [0; 8]; - - // loop to handle EINTR - loop { - match input.read(&mut bytes) { - Ok(0) => return Ok((p, ours)), - Ok(8) => { - assert!(combine(CLOEXEC_MSG_FOOTER) == combine(&bytes[4.. 8]), - "Validation on the CLOEXEC pipe failed: {:?}", bytes); - let errno = combine(&bytes[0.. 4]); - assert!(p.wait().is_ok(), - "wait() should either return Ok or panic"); - return Err(Error::from_raw_os_error(errno)) - } - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => { - assert!(p.wait().is_ok(), - "wait() should either return Ok or panic"); - panic!("the CLOEXEC pipe failed: {:?}", e) - }, - Ok(..) => { // pipe I/O up to PIPE_BUF bytes should be atomic - assert!(p.wait().is_ok(), - "wait() should either return Ok or panic"); - panic!("short read on the CLOEXEC pipe") - } - } - } - - fn combine(arr: &[u8]) -> i32 { - let a = arr[0] as u32; - let b = arr[1] as u32; - let c = arr[2] as u32; - let d = arr[3] as u32; - - ((a << 24) | (b << 16) | (c << 8) | (d << 0)) as i32 - } - } - - pub fn exec(&mut self, default: Stdio) -> io::Error { - let envp = self.capture_env(); - - if self.saw_nul() { - return io::Error::new(ErrorKind::InvalidInput, - "nul byte found in provided data") - } - - match self.setup_io(default, true) { - Ok((_, theirs)) => unsafe { self.do_exec(theirs, envp.as_ref()) }, - Err(e) => e, - } - } - - // And at this point we've reached a special time in the life of the - // child. The child must now be considered hamstrung and unable to - // do anything other than syscalls really. Consider the following - // scenario: - // - // 1. Thread A of process 1 grabs the malloc() mutex - // 2. Thread B of process 1 forks(), creating thread C - // 3. Thread C of process 2 then attempts to malloc() - // 4. The memory of process 2 is the same as the memory of - // process 1, so the mutex is locked. - // - // This situation looks a lot like deadlock, right? It turns out - // that this is what pthread_atfork() takes care of, which is - // presumably implemented across platforms. The first thing that - // threads to *before* forking is to do things like grab the malloc - // mutex, and then after the fork they unlock it. - // - // Despite this information, libnative's spawn has been witnessed to - // deadlock on both macOS and FreeBSD. I'm not entirely sure why, but - // all collected backtraces point at malloc/free traffic in the - // child spawned process. - // - // For this reason, the block of code below should contain 0 - // invocations of either malloc of free (or their related friends). - // - // As an example of not having malloc/free traffic, we don't close - // this file descriptor by dropping the FileDesc (which contains an - // allocation). Instead we just close it manually. This will never - // have the drop glue anyway because this code never returns (the - // child will either exec() or invoke libc::exit) - unsafe fn do_exec( - &mut self, - stdio: ChildPipes, - maybe_envp: Option<&CStringArray> - ) -> io::Error { - use sys::{self, cvt_r}; - - macro_rules! t { - ($e:expr) => (match $e { - Ok(e) => e, - Err(e) => return e, - }) - } - - if let Some(fd) = stdio.stdin.fd() { - t!(cvt_r(|| libc::dup2(fd, libc::STDIN_FILENO))); - } - if let Some(fd) = stdio.stdout.fd() { - t!(cvt_r(|| libc::dup2(fd, libc::STDOUT_FILENO))); - } - if let Some(fd) = stdio.stderr.fd() { - t!(cvt_r(|| libc::dup2(fd, libc::STDERR_FILENO))); - } - - if cfg!(not(any(target_os = "l4re"))) { - if let Some(u) = self.get_gid() { - t!(cvt(libc::setgid(u as gid_t))); - } - if let Some(u) = self.get_uid() { - // When dropping privileges from root, the `setgroups` call - // will remove any extraneous groups. If we don't call this, - // then even though our uid has dropped, we may still have - // groups that enable us to do super-user things. This will - // fail if we aren't root, so don't bother checking the - // return value, this is just done as an optimistic - // privilege dropping function. - let _ = libc::setgroups(0, ptr::null()); - - t!(cvt(libc::setuid(u as uid_t))); - } - } - if let Some(ref cwd) = *self.get_cwd() { - t!(cvt(libc::chdir(cwd.as_ptr()))); - } - if let Some(envp) = maybe_envp { - *sys::os::environ() = envp.as_ptr(); - } - - // emscripten has no signal support. - #[cfg(not(any(target_os = "emscripten")))] - { - use mem; - // Reset signal handling so the child process starts in a - // standardized state. libstd ignores SIGPIPE, and signal-handling - // libraries often set a mask. Child processes inherit ignored - // signals and the signal mask from their parent, but most - // UNIX programs do not reset these things on their own, so we - // need to clean things up now to avoid confusing the program - // we're about to run. - let mut set: libc::sigset_t = mem::uninitialized(); - if cfg!(target_os = "android") { - // Implementing sigemptyset allow us to support older Android - // versions. See the comment about Android and sig* functions in - // process_common.rs - libc::memset(&mut set as *mut _ as *mut _, - 0, - mem::size_of::<libc::sigset_t>()); - } else { - t!(cvt(libc::sigemptyset(&mut set))); - } - t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set, - ptr::null_mut()))); - let ret = sys::signal(libc::SIGPIPE, libc::SIG_DFL); - if ret == libc::SIG_ERR { - return io::Error::last_os_error() - } - } - - for callback in self.get_closures().iter_mut() { - t!(callback()); - } - - libc::execvp(self.get_argv()[0], self.get_argv().as_ptr()); - io::Error::last_os_error() - } - - #[cfg(not(any(target_os = "macos", target_os = "freebsd", - all(target_os = "linux", target_env = "gnu"))))] - fn posix_spawn(&mut self, _: &ChildPipes, _: Option<&CStringArray>) - -> io::Result<Option<Process>> - { - Ok(None) - } - - // Only support platforms for which posix_spawn() can return ENOENT - // directly. - #[cfg(any(target_os = "macos", target_os = "freebsd", - all(target_os = "linux", target_env = "gnu")))] - fn posix_spawn(&mut self, stdio: &ChildPipes, envp: Option<&CStringArray>) - -> io::Result<Option<Process>> - { - use mem; - use sys; - - if self.get_cwd().is_some() || - self.get_gid().is_some() || - self.get_uid().is_some() || - self.env_saw_path() || - self.get_closures().len() != 0 { - return Ok(None) - } - - // Only glibc 2.24+ posix_spawn() supports returning ENOENT directly. - #[cfg(all(target_os = "linux", target_env = "gnu"))] - { - if let Some(version) = sys::os::glibc_version() { - if version < (2, 24) { - return Ok(None) - } - } else { - return Ok(None) - } - } - - let mut p = Process { pid: 0, status: None }; - - struct PosixSpawnFileActions(libc::posix_spawn_file_actions_t); - - impl Drop for PosixSpawnFileActions { - fn drop(&mut self) { - unsafe { - libc::posix_spawn_file_actions_destroy(&mut self.0); - } - } - } - - struct PosixSpawnattr(libc::posix_spawnattr_t); - - impl Drop for PosixSpawnattr { - fn drop(&mut self) { - unsafe { - libc::posix_spawnattr_destroy(&mut self.0); - } - } - } - - unsafe { - let mut file_actions = PosixSpawnFileActions(mem::uninitialized()); - let mut attrs = PosixSpawnattr(mem::uninitialized()); - - libc::posix_spawnattr_init(&mut attrs.0); - libc::posix_spawn_file_actions_init(&mut file_actions.0); - - if let Some(fd) = stdio.stdin.fd() { - cvt(libc::posix_spawn_file_actions_adddup2(&mut file_actions.0, - fd, - libc::STDIN_FILENO))?; - } - if let Some(fd) = stdio.stdout.fd() { - cvt(libc::posix_spawn_file_actions_adddup2(&mut file_actions.0, - fd, - libc::STDOUT_FILENO))?; - } - if let Some(fd) = stdio.stderr.fd() { - cvt(libc::posix_spawn_file_actions_adddup2(&mut file_actions.0, - fd, - libc::STDERR_FILENO))?; - } - - let mut set: libc::sigset_t = mem::uninitialized(); - cvt(libc::sigemptyset(&mut set))?; - cvt(libc::posix_spawnattr_setsigmask(&mut attrs.0, - &set))?; - cvt(libc::sigaddset(&mut set, libc::SIGPIPE))?; - cvt(libc::posix_spawnattr_setsigdefault(&mut attrs.0, - &set))?; - - let flags = libc::POSIX_SPAWN_SETSIGDEF | - libc::POSIX_SPAWN_SETSIGMASK; - cvt(libc::posix_spawnattr_setflags(&mut attrs.0, flags as _))?; - - let envp = envp.map(|c| c.as_ptr()) - .unwrap_or(*sys::os::environ() as *const _); - let ret = libc::posix_spawnp( - &mut p.pid, - self.get_argv()[0], - &file_actions.0, - &attrs.0, - self.get_argv().as_ptr() as *const _, - envp as *const _, - ); - if ret == 0 { - Ok(Some(p)) - } else { - Err(io::Error::from_raw_os_error(ret)) - } - } - } -} - -//////////////////////////////////////////////////////////////////////////////// -// Processes -//////////////////////////////////////////////////////////////////////////////// - -/// The unique id of the process (this should never be negative). -pub struct Process { - pid: pid_t, - status: Option<ExitStatus>, -} - -impl Process { - pub fn id(&self) -> u32 { - self.pid as u32 - } - - pub fn kill(&mut self) -> io::Result<()> { - // If we've already waited on this process then the pid can be recycled - // and used for another process, and we probably shouldn't be killing - // random processes, so just return an error. - if self.status.is_some() { - Err(Error::new(ErrorKind::InvalidInput, - "invalid argument: can't kill an exited process")) - } else { - cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(|_| ()) - } - } - - pub fn wait(&mut self) -> io::Result<ExitStatus> { - use sys::cvt_r; - if let Some(status) = self.status { - return Ok(status) - } - let mut status = 0 as c_int; - cvt_r(|| unsafe { libc::waitpid(self.pid, &mut status, 0) })?; - self.status = Some(ExitStatus::new(status)); - Ok(ExitStatus::new(status)) - } - - pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> { - if let Some(status) = self.status { - return Ok(Some(status)) - } - let mut status = 0 as c_int; - let pid = cvt(unsafe { - libc::waitpid(self.pid, &mut status, libc::WNOHANG) - })?; - if pid == 0 { - Ok(None) - } else { - self.status = Some(ExitStatus::new(status)); - Ok(Some(ExitStatus::new(status))) - } - } -} |