| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary. |
| 2 | Copyright (C) 1995-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <hurd.h> |
| 20 | #include <hurd/signal.h> |
| 21 | |
| 22 | /* Call *RPC on PORT and/or CTTY. If a call on CTTY returns EBACKGROUND, |
| 23 | generate SIGTTOU if appropriate. */ |
| 24 | |
| 25 | error_t |
| 26 | _hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t)) |
| 27 | { |
| 28 | if (ctty == MACH_PORT_NULL) |
| 29 | return (*rpc) (port); |
| 30 | else |
| 31 | { |
| 32 | struct hurd_sigstate *ss = _hurd_self_sigstate (); |
| 33 | error_t err; |
| 34 | |
| 35 | do |
| 36 | { |
| 37 | /* Don't use the ctty io port if we are blocking or ignoring |
| 38 | SIGTTOU. We redo this check at the top of the loop in case |
| 39 | the signal handler changed the state. */ |
| 40 | __spin_lock (&ss->lock); |
| 41 | if (__sigismember (&ss->blocked, SIGTTOU) || |
| 42 | ss->actions[SIGTTOU].sa_handler == SIG_IGN) |
| 43 | err = EIO; |
| 44 | else |
| 45 | err = 0; |
| 46 | __spin_unlock (&ss->lock); |
| 47 | |
| 48 | if (err) |
| 49 | return (*rpc) (port); |
| 50 | |
| 51 | err = (*rpc) (ctty); |
| 52 | if (err == EBACKGROUND) |
| 53 | { |
| 54 | if (_hurd_orphaned) |
| 55 | /* Our process group is orphaned, so we never generate a |
| 56 | signal; we just fail. */ |
| 57 | err = EIO; |
| 58 | else |
| 59 | { |
| 60 | /* Send a SIGTTOU signal to our process group. |
| 61 | |
| 62 | We must remember here not to clobber ERR, since |
| 63 | the loop condition below uses it to recall that |
| 64 | we should retry after a stop. */ |
| 65 | |
| 66 | __USEPORT (CTTYID, _hurd_sig_post (0, SIGTTOU, port)); |
| 67 | /* XXX what to do if error here? */ |
| 68 | |
| 69 | /* At this point we should have just run the handler for |
| 70 | SIGTTOU or resumed after being stopped. Now this is |
| 71 | still a "system call", so check to see if we should |
| 72 | restart it. */ |
| 73 | __spin_lock (&ss->lock); |
| 74 | if (!(ss->actions[SIGTTOU].sa_flags & SA_RESTART)) |
| 75 | err = EINTR; |
| 76 | __spin_unlock (&ss->lock); |
| 77 | } |
| 78 | } |
| 79 | /* If the last RPC generated a SIGTTOU, loop to try it again. */ |
| 80 | } while (err == EBACKGROUND); |
| 81 | |
| 82 | return err; |
| 83 | } |
| 84 | } |