85 lines
2.6 KiB
C
85 lines
2.6 KiB
C
/* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary.
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Copyright (C) 1995-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <hurd.h>
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#include <hurd/signal.h>
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/* Call *RPC on PORT and/or CTTY. If a call on CTTY returns EBACKGROUND,
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generate SIGTTOU if appropriate. */
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error_t
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_hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t))
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{
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if (ctty == MACH_PORT_NULL)
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return (*rpc) (port);
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else
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{
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struct hurd_sigstate *ss = _hurd_self_sigstate ();
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error_t err;
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do
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{
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/* Don't use the ctty io port if we are blocking or ignoring
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SIGTTOU. We redo this check at the top of the loop in case
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the signal handler changed the state. */
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__spin_lock (&ss->lock);
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if (__sigismember (&ss->blocked, SIGTTOU) ||
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ss->actions[SIGTTOU].sa_handler == SIG_IGN)
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err = EIO;
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else
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err = 0;
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__spin_unlock (&ss->lock);
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if (err)
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return (*rpc) (port);
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err = (*rpc) (ctty);
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if (err == EBACKGROUND)
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{
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if (_hurd_orphaned)
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/* Our process group is orphaned, so we never generate a
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signal; we just fail. */
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err = EIO;
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else
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{
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/* Send a SIGTTOU signal to our process group.
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We must remember here not to clobber ERR, since
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the loop condition below uses it to recall that
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we should retry after a stop. */
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__USEPORT (CTTYID, _hurd_sig_post (0, SIGTTOU, port));
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/* XXX what to do if error here? */
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/* At this point we should have just run the handler for
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SIGTTOU or resumed after being stopped. Now this is
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still a "system call", so check to see if we should
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restart it. */
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__spin_lock (&ss->lock);
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if (!(ss->actions[SIGTTOU].sa_flags & SA_RESTART))
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err = EINTR;
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__spin_unlock (&ss->lock);
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}
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}
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/* If the last RPC generated a SIGTTOU, loop to try it again. */
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} while (err == EBACKGROUND);
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return err;
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}
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}
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