/* Duplicate FD to FD2, closing the old FD2 and making FD2 be
open on the same file as FD is, and setting FD2's flags according to FLAGS.
Return FD2 or -1. */
int
__dup3 (int fd, int fd2, int flags)
{
struct hurd_fd *d;
/* Both passing flags different from O_CLOEXEC and FD2 being the same as FD
are invalid. */
if ((flags & ~O_CLOEXEC
|| fd2 == fd)
/* ... with the exception in case that dup2 behavior is requested: if FD
is valid and FD2 is already the same then just return it. */
&& ! (flags == -1
&& fd2 == fd))
return __hurd_fail (EINVAL);
/* Extract the ports and flags from FD. */
d = _hurd_fd_get (fd);
if (d == NULL)
return __hurd_fail (EBADF);
HURD_CRITICAL_BEGIN;
__spin_lock (&d->port.lock);
if (d->port.port == MACH_PORT_NULL)
{
__spin_unlock (&d->port.lock);
fd2 = __hurd_fail (EBADF);
}
else if (fd2 == fd)
__spin_unlock (&d->port.lock);
else
{
struct hurd_userlink ulink, ctty_ulink;
int d_flags = d->flags;
io_t ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
io_t port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */
if (fd2 < 0)
fd2 = __hurd_fail (EBADF);
else
{
/* Get a hold of the destination descriptor. */
struct hurd_fd *d2;
__mutex_lock (&_hurd_dtable_lock);
if (fd2 >= _hurd_dtablesize)
{
/* The table is not large enough to hold the destination
descriptor. Enlarge it as necessary to allocate this
descriptor. */
__mutex_unlock (&_hurd_dtable_lock);
d2 = _hurd_alloc_fd (NULL, fd2);
if (d2)
__spin_unlock (&d2->port.lock);
__mutex_lock (&_hurd_dtable_lock);
}
else
{
d2 = _hurd_dtable[fd2];
if (d2 == NULL)
{
/* Must allocate a new one. We don't initialize the port
cells with this call so that if it fails (out of
memory), we will not have already added user
references for the ports, which we would then have to
deallocate. */
d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL,
MACH_PORT_NULL);
}
}
__mutex_unlock (&_hurd_dtable_lock);
if (d2 == NULL)
{
fd2 = -1;
if (errno == EINVAL)
errno = EBADF; /* POSIX.1-1990 6.2.1.2 ll 54-55. */
}
else
{
/* Give the ports each a user ref for the new descriptor. */
__mach_port_mod_refs (__mach_task_self (), port,
MACH_PORT_RIGHT_SEND, 1);
if (ctty != MACH_PORT_NULL)
__mach_port_mod_refs (__mach_task_self (), ctty,
MACH_PORT_RIGHT_SEND, 1);
/* Install the ports and flags in the new descriptor slot. */
__spin_lock (&d2->port.lock);
if (flags & O_CLOEXEC)
d2->flags = d_flags | FD_CLOEXEC;
else
/* dup clears FD_CLOEXEC. */
d2->flags = d_flags & ~FD_CLOEXEC;
_hurd_port_set (&d2->ctty, ctty);
_hurd_port_locked_set (&d2->port, port); /* Unlocks D2. */
}
}
_hurd_port_free (&d->port, &ulink, port);
if (ctty != MACH_PORT_NULL)
_hurd_port_free (&d->ctty, &ctty_ulink, port);
}
HURD_CRITICAL_END;
return fd2;
}
/* 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;
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;
unsigned int dtablesize, i;
struct hurd_port **dtable_cells;
struct hurd_userlink *ulink_dtable;
struct hurd_sigstate *ss;
mach_port_t *please_dealloc, *pdp;
/* XXX needs to be hurdmalloc XXX */
if (err = __argz_create (argv, &args, &argslen))
return err;
if (err = __argz_create (envp, &env, &envlen))
goto outargs;
/* 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]);
goto outenv;
}
}
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;
case INIT_TRACEMASK:
ints[i] = _hurdsig_traced;
break;
default:
ints[i] = 0;
}
ss = _hurd_self_sigstate ();
assert (! __spin_lock_locked (&ss->critical_section_lock));
__spin_lock (&ss->critical_section_lock);
__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. */
__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, 0,
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,
&_hurd_msgport, task == __mach_task_self () ? 1 : 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. */
_hurd_critical_section_unlock (ss);
outargs:
free (args);
outenv:
free (env);
return err;
}
