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-rw-r--r--hurd/hurdexec.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/hurd/hurdexec.c b/hurd/hurdexec.c
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+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <hurd/signal.h>
+
+/* Overlay TASK, executing FILE with arguments ARGV and environment ENVP.
+ If TASK == mach_task_self (), some ports are dealloc'd by the exec server.
+ ARGV and ENVP are terminated by NULL pointers. */
+error_t
+_hurd_exec (task_t task, file_t file,
+ char *const argv[], char *const envp[])
+{
+ error_t err;
+ char *args, *env, *ap;
+ size_t argslen, envlen;
+ int ints[INIT_INT_MAX];
+ mach_port_t ports[_hurd_nports];
+ struct hurd_userlink ulink_ports[_hurd_nports];
+ file_t *dtable;
+ int dtablesize;
+ struct hurd_port **dtable_cells;
+ struct hurd_userlink *ulink_dtable;
+ int i;
+ char *const *p;
+ struct hurd_sigstate *ss;
+ mach_port_t *please_dealloc, *pdp;
+
+
+ /* Pack the arguments into an array with nulls separating the elements. */
+ argslen = 0;
+ if (argv != NULL)
+ {
+ p = argv;
+ while (*p != NULL)
+ argslen += strlen (*p++) + 1;
+ args = __alloca (argslen);
+ ap = args;
+ for (p = argv; *p != NULL; ++p)
+ ap = __memccpy (ap, *p, '\0', ULONG_MAX);
+ }
+ else
+ args = NULL;
+
+ /* Pack the environment into an array with nulls separating elements. */
+ envlen = 0;
+ if (envp != NULL)
+ {
+ p = envp;
+ while (*p != NULL)
+ envlen += strlen (*p++) + 1;
+ env = __alloca (envlen);
+ ap = env;
+ for (p = envp; *p != NULL; ++p)
+ ap = __memccpy (ap, *p, '\0', ULONG_MAX);
+ }
+ else
+ env = NULL;
+
+ /* Load up the ports to give to the new program. */
+ for (i = 0; i < _hurd_nports; ++i)
+ if (i == INIT_PORT_PROC && task != __mach_task_self ())
+ {
+ /* This is another task, so we need to ask the proc server
+ for the right proc server port for it. */
+ if (err = __USEPORT (PROC, __proc_task2proc (port, task, &ports[i])))
+ {
+ while (--i > 0)
+ _hurd_port_free (&_hurd_ports[i], &ulink_ports[i], ports[i]);
+ return err;
+ }
+ }
+ else
+ ports[i] = _hurd_port_get (&_hurd_ports[i], &ulink_ports[i]);
+
+
+ /* Load up the ints to give the new program. */
+ for (i = 0; i < INIT_INT_MAX; ++i)
+ switch (i)
+ {
+ case INIT_UMASK:
+ ints[i] = _hurd_umask;
+ break;
+
+ case INIT_SIGMASK:
+ case INIT_SIGIGN:
+ case INIT_SIGPENDING:
+ /* We will set these all below. */
+ break;
+
+ default:
+ ints[i] = 0;
+ }
+
+ ss = _hurd_self_sigstate ();
+ __spin_lock (&ss->lock);
+ ints[INIT_SIGMASK] = ss->blocked;
+ ints[INIT_SIGPENDING] = ss->pending;
+ ints[INIT_SIGIGN] = 0;
+ for (i = 1; i < NSIG; ++i)
+ if (ss->actions[i].sa_handler == SIG_IGN)
+ ints[INIT_SIGIGN] |= __sigmask (i);
+
+ /* We hold the sigstate lock until the exec has failed so that no signal
+ can arrive between when we pack the blocked and ignored signals, and
+ when the exec actually happens. A signal handler could change what
+ signals are blocked and ignored. Either the change will be reflected
+ in the exec, or the signal will never be delivered. Setting the
+ critical section flag avoids anything we call trying to acquire the
+ sigstate lock. */
+
+ ss->critical_section = 1;
+ __spin_unlock (&ss->lock);
+
+ /* Pack up the descriptor table to give the new program. */
+ __mutex_lock (&_hurd_dtable_lock);
+
+ dtablesize = _hurd_dtable ? _hurd_dtablesize : _hurd_init_dtablesize;
+
+ if (task == __mach_task_self ())
+ /* Request the exec server to deallocate some ports from us if the exec
+ succeeds. The init ports and descriptor ports will arrive in the
+ new program's exec_startup message. If we failed to deallocate
+ them, the new program would have duplicate user references for them.
+ But we cannot deallocate them ourselves, because we must still have
+ them after a failed exec call. */
+ please_dealloc = __alloca ((_hurd_nports + (2 * dtablesize))
+ * sizeof (mach_port_t));
+ else
+ please_dealloc = NULL;
+ pdp = please_dealloc;
+
+ if (_hurd_dtable != NULL)
+ {
+ dtable = __alloca (dtablesize * sizeof (dtable[0]));
+ ulink_dtable = __alloca (dtablesize * sizeof (ulink_dtable[0]));
+ dtable_cells = __alloca (dtablesize * sizeof (dtable_cells[0]));
+ for (i = 0; i < dtablesize; ++i)
+ {
+ struct hurd_fd *const d = _hurd_dtable[i];
+ if (d == NULL)
+ {
+ dtable[i] = MACH_PORT_NULL;
+ continue;
+ }
+ __spin_lock (&d->port.lock);
+ if (d->flags & FD_CLOEXEC)
+ {
+ /* This descriptor is marked to be closed on exec.
+ So don't pass it to the new program. */
+ dtable[i] = MACH_PORT_NULL;
+ if (pdp && d->port.port != MACH_PORT_NULL)
+ {
+ /* We still need to deallocate the ports. */
+ *pdp++ = d->port.port;
+ if (d->ctty.port != MACH_PORT_NULL)
+ *pdp++ = d->ctty.port;
+ }
+ __spin_unlock (&d->port.lock);
+ }
+ else
+ {
+ if (pdp && d->ctty.port != MACH_PORT_NULL)
+ /* All the elements of DTABLE are added to PLEASE_DEALLOC
+ below, so we needn't add the port itself.
+ But we must deallocate the ctty port as well as
+ the normal port that got installed in DTABLE[I]. */
+ *pdp++ = d->ctty.port;
+ dtable[i] = _hurd_port_locked_get (&d->port, &ulink_dtable[i]);
+ dtable_cells[i] = &d->port;
+ }
+ }
+ }
+ else
+ {
+ dtable = _hurd_init_dtable;
+ ulink_dtable = NULL;
+ dtable_cells = NULL;
+ }
+
+ /* The information is all set up now. Try to exec the file. */
+
+ {
+ if (pdp)
+ {
+ /* Request the exec server to deallocate some ports from us if the exec
+ succeeds. The init ports and descriptor ports will arrive in the
+ new program's exec_startup message. If we failed to deallocate
+ them, the new program would have duplicate user references for them.
+ But we cannot deallocate them ourselves, because we must still have
+ them after a failed exec call. */
+
+ for (i = 0; i < _hurd_nports; ++i)
+ *pdp++ = ports[i];
+ for (i = 0; i < dtablesize; ++i)
+ *pdp++ = dtable[i];
+ }
+
+ err = __file_exec (file, task,
+ _hurd_exec_flags & EXEC_INHERITED,
+ args, argslen, env, envlen,
+ dtable, MACH_MSG_TYPE_COPY_SEND, dtablesize,
+ ports, MACH_MSG_TYPE_COPY_SEND, _hurd_nports,
+ ints, INIT_INT_MAX,
+ please_dealloc, pdp - please_dealloc,
+ NULL, 0);
+ }
+
+ /* Release references to the standard ports. */
+ for (i = 0; i < _hurd_nports; ++i)
+ if (i == INIT_PORT_PROC && task != __mach_task_self ())
+ __mach_port_deallocate (__mach_task_self (), ports[i]);
+ else
+ _hurd_port_free (&_hurd_ports[i], &ulink_ports[i], ports[i]);
+
+ if (ulink_dtable != NULL)
+ /* Release references to the file descriptor ports. */
+ for (i = 0; i < dtablesize; ++i)
+ if (dtable[i] != MACH_PORT_NULL)
+ _hurd_port_free (dtable_cells[i], &ulink_dtable[i], dtable[i]);
+
+ /* Release lock on the file descriptor table. */
+ __mutex_unlock (&_hurd_dtable_lock);
+
+ /* Safe to let signals happen now. */
+ {
+ sigset_t pending;
+ __spin_lock (&ss->lock);
+ ss->critical_section = 0;
+ pending = ss->pending & ~ss->blocked;
+ __spin_unlock (&ss->lock);
+ if (pending)
+ __msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+ }
+
+ return err;
+}