diff options
Diffstat (limited to 'src/command.rs')
| -rw-r--r-- | src/command.rs | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/src/command.rs b/src/command.rs index 926e097..f5357d2 100644 --- a/src/command.rs +++ b/src/command.rs @@ -15,17 +15,42 @@ impl Command for std::process::Command { let pt_fd = pty.pt().as_raw_fd(); let pts_fd = pts.as_raw_fd(); - self.stdin(unsafe { std::process::Stdio::from_raw_fd(pts_fd) }) - .stdout(unsafe { std::process::Stdio::from_raw_fd(pts_fd) }) - .stderr(unsafe { std::process::Stdio::from_raw_fd(pts_fd) }); + let stdin = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?; + let stdout = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?; + let stderr = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?; + // safe because the fds are valid (otherwise pty.pts() or dup() would + // have returned an Err and we would have exited early) and are not + // owned by any other structure (since dup() returns a fresh copy of + // the file descriptor), allowing from_raw_fd to take ownership of it. + self.stdin(unsafe { std::process::Stdio::from_raw_fd(stdin) }) + .stdout(unsafe { std::process::Stdio::from_raw_fd(stdout) }) + .stderr(unsafe { std::process::Stdio::from_raw_fd(stderr) }); + + // safe because the only thing this function does is call close(), + // which is an async-signal-safe function unsafe { self.pre_exec(move || { + // in the parent, destructors will handle closing these file + // descriptors (other than pt, used by the parent to + // communicate with the child) when the function ends, but in + // the child, we end by calling exec(), which doesn't call + // destructors. + // XXX unwrap nix::unistd::close(pt_fd) .map_err(|e| e.as_errno().unwrap())?; nix::unistd::close(pts_fd) .map_err(|e| e.as_errno().unwrap())?; + // at this point, stdin/stdout/stderr have already been + // reopened as fds 0/1/2 in the child, so we can (and should) + // close the originals + nix::unistd::close(stdin) + .map_err(|e| e.as_errno().unwrap())?; + nix::unistd::close(stdout) + .map_err(|e| e.as_errno().unwrap())?; + nix::unistd::close(stderr) + .map_err(|e| e.as_errno().unwrap())?; Ok(()) }); } |