| 1 | /* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary. |
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| 2 | Copyright (C) 1995-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <hurd.h> |
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| 20 | #include <hurd/signal.h> |
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| 21 | |
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| 22 | /* Call *RPC on PORT and/or CTTY. If a call on CTTY returns EBACKGROUND, |
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| 23 | generate SIGTTOU if appropriate. */ |
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| 24 | |
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| 25 | error_t |
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| 26 | _hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t)) |
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| 27 | { |
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| 28 | if (ctty == MACH_PORT_NULL) |
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| 29 | return (*rpc) (port); |
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| 30 | else |
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| 31 | { |
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| 32 | struct hurd_sigstate *ss = _hurd_self_sigstate (); |
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| 33 | error_t err; |
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| 34 | |
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| 35 | do |
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| 36 | { |
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| 37 | struct sigaction *actions; |
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| 38 | |
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| 39 | /* Don't use the ctty io port if we are blocking or ignoring |
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| 40 | SIGTTOU. We redo this check at the top of the loop in case |
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| 41 | the signal handler changed the state. */ |
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| 42 | _hurd_sigstate_lock (ss); |
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| 43 | actions = _hurd_sigstate_actions (ss); |
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| 44 | if (__sigismember (set: &ss->blocked, SIGTTOU) |
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| 45 | || actions[SIGTTOU].sa_handler == SIG_IGN) |
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| 46 | err = EIO; |
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| 47 | else |
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| 48 | err = 0; |
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| 49 | _hurd_sigstate_unlock (ss); |
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| 50 | |
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| 51 | if (err) |
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| 52 | return (*rpc) (port); |
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| 53 | |
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| 54 | err = (*rpc) (ctty); |
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| 55 | if (err == EBACKGROUND) |
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| 56 | { |
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| 57 | if (_hurd_orphaned) |
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| 58 | /* Our process group is orphaned, so we never generate a |
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| 59 | signal; we just fail. */ |
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| 60 | err = EIO; |
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| 61 | else |
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| 62 | { |
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| 63 | /* Send a SIGTTOU signal to our process group. |
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| 64 | |
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| 65 | We must remember here not to clobber ERR, since |
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| 66 | the loop condition below uses it to recall that |
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| 67 | we should retry after a stop. */ |
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| 68 | |
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| 69 | __USEPORT (CTTYID, _hurd_sig_post (0, SIGTTOU, port)); |
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| 70 | /* XXX what to do if error here? */ |
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| 71 | |
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| 72 | /* At this point we should have just run the handler for |
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| 73 | SIGTTOU or resumed after being stopped. Now this is |
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| 74 | still a "system call", so check to see if we should |
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| 75 | restart it. */ |
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| 76 | _hurd_sigstate_lock (ss); |
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| 77 | actions = _hurd_sigstate_actions (ss); |
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| 78 | if (!(actions[SIGTTOU].sa_flags & SA_RESTART)) |
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| 79 | err = EINTR; |
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| 80 | _hurd_sigstate_unlock (ss); |
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| 81 | } |
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| 82 | } |
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| 83 | /* If the last RPC generated a SIGTTOU, loop to try it again. */ |
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| 84 | } while (err == EBACKGROUND); |
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| 85 | |
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| 86 | return err; |
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| 87 | } |
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| 88 | } |
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| 89 | |
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