| 1 | /* Copyright (C) 1993-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <errno.h> |
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| 19 | #include <unistd.h> |
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| 20 | #include <hurd.h> |
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| 21 | #include <hurd/port.h> |
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| 22 | #include <hurd/fd.h> |
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| 23 | #include <hurd/ioctl.h> |
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| 24 | #include <lowlevellock.h> |
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| 25 | |
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| 26 | /* Create a new session with the calling process as its leader. |
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| 27 | The process group IDs of the session and the calling process |
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| 28 | are set to the process ID of the calling process, which is returned. */ |
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| 29 | pid_t |
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| 30 | __setsid (void) |
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| 31 | { |
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| 32 | error_t err; |
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| 33 | unsigned int stamp; |
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| 34 | |
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| 35 | retry: |
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| 36 | HURD_CRITICAL_BEGIN; |
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| 37 | __mutex_lock (&_hurd_dtable_lock); |
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| 38 | |
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| 39 | stamp = _hurd_pids_changed_stamp; /* Atomic fetch. */ |
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| 40 | |
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| 41 | /* Tell the proc server we want to start a new session. */ |
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| 42 | err = __USEPORT (PROC, __proc_setsid (port)); |
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| 43 | if (err) |
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| 44 | __mutex_unlock (&_hurd_dtable_lock); |
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| 45 | else |
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| 46 | { |
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| 47 | /* Punt our current ctty, and update the dtable accordingly. We hold |
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| 48 | the dtable lock from before the proc_setsid call through clearing |
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| 49 | the cttyid port and processing the dtable, so that we can be sure |
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| 50 | that it's all done by the time the signal thread processes the |
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| 51 | pgrp change notification. */ |
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| 52 | _hurd_locked_install_cttyid (MACH_PORT_NULL); |
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| 53 | |
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| 54 | /* Synchronize with the signal thread to make sure we have received |
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| 55 | and processed proc_newids before returning to the user. |
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| 56 | This is necessary to ensure that _hurd_pgrp (and thus the value |
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| 57 | returned by `getpgrp ()' in other threads) has been updated before |
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| 58 | we return. */ |
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| 59 | while (_hurd_pids_changed_stamp == stamp) |
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| 60 | lll_wait (_hurd_pids_changed_stamp, stamp, 0); |
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| 61 | } |
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| 62 | |
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| 63 | HURD_CRITICAL_END; |
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| 64 | if (err == EINTR) |
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| 65 | /* Got a signal while inside an RPC of the critical section, retry again */ |
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| 66 | goto retry; |
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| 67 | |
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| 68 | return err ? __hurd_fail (err) : _hurd_pgrp; |
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| 69 | } |
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| 70 | |
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| 71 | weak_alias (__setsid, setsid) |
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| 72 | |
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