/* Prepare a wakeup message. */
static error_t
create_wakeupmsg (struct __pthread *thread)
{
kern_return_t err;
/* Build wakeup message. */
thread->wakeupmsg.msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND, 0);
thread->wakeupmsg.msgh_size = 0;
err = __mach_port_allocate (__mach_task_self (), MACH_PORT_RIGHT_RECEIVE,
&thread->wakeupmsg.msgh_remote_port);
if (err)
return EAGAIN;
thread->wakeupmsg.msgh_local_port = MACH_PORT_NULL;
thread->wakeupmsg.msgh_seqno = 0;
thread->wakeupmsg.msgh_id = 0;
err = __mach_port_insert_right (__mach_task_self (),
thread->wakeupmsg.msgh_remote_port,
thread->wakeupmsg.msgh_remote_port,
MACH_MSG_TYPE_MAKE_SEND);
if (err)
{
__mach_port_destroy (__mach_task_self (),
thread->wakeupmsg.msgh_remote_port);
return EAGAIN;
}
return 0;
}
/* Check the first NFDS descriptors either in POLLFDS (if nonnnull) or in
each of READFDS, WRITEFDS, EXCEPTFDS that is nonnull. If TIMEOUT is not
NULL, time out after waiting the interval specified therein. Returns
the number of ready descriptors, or -1 for errors. */
int
_hurd_select (int nfds,
struct pollfd *pollfds,
fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
const struct timespec *timeout, const sigset_t *sigmask)
{
int i;
mach_port_t portset;
int got;
error_t err;
fd_set rfds, wfds, xfds;
int firstfd, lastfd;
mach_msg_timeout_t to = 0;
struct
{
struct hurd_userlink ulink;
struct hurd_fd *cell;
mach_port_t io_port;
int type;
mach_port_t reply_port;
} d[nfds];
sigset_t oset;
union typeword /* Use this to avoid unkosher casts. */
{
mach_msg_type_t type;
uint32_t word;
};
assert (sizeof (union typeword) == sizeof (mach_msg_type_t));
assert (sizeof (uint32_t) == sizeof (mach_msg_type_t));
if (nfds < 0 || (pollfds == NULL && nfds > FD_SETSIZE))
{
errno = EINVAL;
return -1;
}
if (timeout != NULL)
{
if (timeout->tv_sec < 0 || timeout->tv_nsec < 0)
{
errno = EINVAL;
return -1;
}
to = (timeout->tv_sec * 1000 +
(timeout->tv_nsec + 999999) / 1000000);
}
if (sigmask && __sigprocmask (SIG_SETMASK, sigmask, &oset))
return -1;
if (pollfds)
{
/* Collect interesting descriptors from the user's `pollfd' array.
We do a first pass that reads the user's array before taking
any locks. The second pass then only touches our own stack,
and gets the port references. */
for (i = 0; i < nfds; ++i)
if (pollfds[i].fd >= 0)
{
int type = 0;
if (pollfds[i].events & POLLIN)
type |= SELECT_READ;
if (pollfds[i].events & POLLOUT)
type |= SELECT_WRITE;
if (pollfds[i].events & POLLPRI)
type |= SELECT_URG;
d[i].io_port = pollfds[i].fd;
d[i].type = type;
}
else
d[i].type = 0;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_dtable_lock);
for (i = 0; i < nfds; ++i)
if (d[i].type != 0)
{
const int fd = (int) d[i].io_port;
if (fd < _hurd_dtablesize)
{
d[i].cell = _hurd_dtable[fd];
d[i].io_port = _hurd_port_get (&d[i].cell->port, &d[i].ulink);
if (d[i].io_port != MACH_PORT_NULL)
continue;
}
/* If one descriptor is bogus, we fail completely. */
while (i-- > 0)
if (d[i].type != 0)
_hurd_port_free (&d[i].cell->port,
&d[i].ulink, d[i].io_port);
break;
}
__mutex_unlock (&_hurd_dtable_lock);
HURD_CRITICAL_END;
if (i < nfds)
{
if (sigmask)
__sigprocmask (SIG_SETMASK, &oset, NULL);
errno = EBADF;
return -1;
}
lastfd = i - 1;
firstfd = i == 0 ? lastfd : 0;
}
else
{
/* Collect interested descriptors from the user's fd_set arguments.
Use local copies so we can't crash from user bogosity. */
if (readfds == NULL)
FD_ZERO (&rfds);
else
rfds = *readfds;
if (writefds == NULL)
FD_ZERO (&wfds);
else
wfds = *writefds;
if (exceptfds == NULL)
FD_ZERO (&xfds);
else
xfds = *exceptfds;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_dtable_lock);
if (nfds > _hurd_dtablesize)
nfds = _hurd_dtablesize;
/* Collect the ports for interesting FDs. */
firstfd = lastfd = -1;
for (i = 0; i < nfds; ++i)
{
int type = 0;
if (readfds != NULL && FD_ISSET (i, &rfds))
type |= SELECT_READ;
if (writefds != NULL && FD_ISSET (i, &wfds))
type |= SELECT_WRITE;
if (exceptfds != NULL && FD_ISSET (i, &xfds))
type |= SELECT_URG;
d[i].type = type;
if (type)
{
d[i].cell = _hurd_dtable[i];
d[i].io_port = _hurd_port_get (&d[i].cell->port, &d[i].ulink);
if (d[i].io_port == MACH_PORT_NULL)
{
/* If one descriptor is bogus, we fail completely. */
while (i-- > 0)
if (d[i].type != 0)
_hurd_port_free (&d[i].cell->port, &d[i].ulink,
d[i].io_port);
break;
}
lastfd = i;
if (firstfd == -1)
firstfd = i;
}
}
__mutex_unlock (&_hurd_dtable_lock);
HURD_CRITICAL_END;
if (i < nfds)
{
if (sigmask)
__sigprocmask (SIG_SETMASK, &oset, NULL);
errno = EBADF;
return -1;
}
}
err = 0;
got = 0;
/* Send them all io_select request messages. */
if (firstfd == -1)
/* But not if there were no ports to deal with at all.
We are just a pure timeout. */
portset = __mach_reply_port ();
else
{
portset = MACH_PORT_NULL;
for (i = firstfd; i <= lastfd; ++i)
if (d[i].type)
{
int type = d[i].type;
d[i].reply_port = __mach_reply_port ();
err = __io_select (d[i].io_port, d[i].reply_port,
/* Poll only if there's a single descriptor. */
(firstfd == lastfd) ? to : 0,
&type);
switch (err)
{
case MACH_RCV_TIMED_OUT:
/* No immediate response. This is normal. */
err = 0;
if (firstfd == lastfd)
/* When there's a single descriptor, we don't need a
portset, so just pretend we have one, but really
use the single reply port. */
portset = d[i].reply_port;
else if (got == 0)
/* We've got multiple reply ports, so we need a port set to
multiplex them. */
{
/* We will wait again for a reply later. */
if (portset == MACH_PORT_NULL)
/* Create the portset to receive all the replies on. */
err = __mach_port_allocate (__mach_task_self (),
MACH_PORT_RIGHT_PORT_SET,
&portset);
if (! err)
/* Put this reply port in the port set. */
__mach_port_move_member (__mach_task_self (),
d[i].reply_port, portset);
}
break;
default:
/* No other error should happen. Callers of select
don't expect to see errors, so we simulate
readiness of the erring object and the next call
hopefully will get the error again. */
type = SELECT_ALL;
/* FALLTHROUGH */
case 0:
/* We got an answer. */
if ((type & SELECT_ALL) == 0)
/* Bogus answer; treat like an error, as a fake positive. */
type = SELECT_ALL;
/* This port is already ready already. */
d[i].type &= type;
d[i].type |= SELECT_RETURNED;
++got;
break;
}
_hurd_port_free (&d[i].cell->port, &d[i].ulink, d[i].io_port);
}
}
/* Now wait for reply messages. */
if (!err && got == 0)
{
/* Now wait for io_select_reply messages on PORT,
timing out as appropriate. */
union
{
mach_msg_header_t head;
#ifdef MACH_MSG_TRAILER_MINIMUM_SIZE
struct
{
mach_msg_header_t head;
NDR_record_t ndr;
error_t err;
} error;
struct
{
mach_msg_header_t head;
NDR_record_t ndr;
error_t err;
int result;
mach_msg_trailer_t trailer;
} success;
#else
struct
{
mach_msg_header_t head;
union typeword err_type;
error_t err;
} error;
struct
{
mach_msg_header_t head;
union typeword err_type;
error_t err;
union typeword result_type;
int result;
} success;
#endif
} msg;
mach_msg_option_t options = (timeout == NULL ? 0 : MACH_RCV_TIMEOUT);
error_t msgerr;
while ((msgerr = __mach_msg (&msg.head,
MACH_RCV_MSG | MACH_RCV_INTERRUPT | options,
0, sizeof msg, portset, to,
MACH_PORT_NULL)) == MACH_MSG_SUCCESS)
{
/* We got a message. Decode it. */
#define IO_SELECT_REPLY_MSGID (21012 + 100) /* XXX */
#ifdef MACH_MSG_TYPE_BIT
const union typeword inttype =
{ type:
{ MACH_MSG_TYPE_INTEGER_T, sizeof (integer_t) * 8, 1, 1, 0, 0 }
};
#endif
if (msg.head.msgh_id == IO_SELECT_REPLY_MSGID &&
msg.head.msgh_size >= sizeof msg.error &&
!(msg.head.msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
#ifdef MACH_MSG_TYPE_BIT
msg.error.err_type.word == inttype.word
#endif
)
{
/* This is a properly formatted message so far.
See if it is a success or a failure. */
if (msg.error.err == EINTR &&
msg.head.msgh_size == sizeof msg.error)
{
/* EINTR response; poll for further responses
and then return quickly. */
err = EINTR;
goto poll;
}
if (msg.error.err ||
msg.head.msgh_size != sizeof msg.success ||
#ifdef MACH_MSG_TYPE_BIT
msg.success.result_type.word != inttype.word ||
#endif
(msg.success.result & SELECT_ALL) == 0)
{
/* Error or bogus reply. Simulate readiness. */
__mach_msg_destroy (&msg.head);
msg.success.result = SELECT_ALL;
}
/* Look up the respondent's reply port and record its
readiness. */
{
int had = got;
if (firstfd != -1)
for (i = firstfd; i <= lastfd; ++i)
if (d[i].type
&& d[i].reply_port == msg.head.msgh_local_port)
{
d[i].type &= msg.success.result;
d[i].type |= SELECT_RETURNED;
++got;
}
assert (got > had);
}
}
if (msg.head.msgh_remote_port != MACH_PORT_NULL)
__mach_port_deallocate (__mach_task_self (),
msg.head.msgh_remote_port);
if (got)
poll:
{
/* Poll for another message. */
to = 0;
options |= MACH_RCV_TIMEOUT;
}
}
if (msgerr == MACH_RCV_INTERRUPTED)
/* Interruption on our side (e.g. signal reception). */
err = EINTR;
if (got)
/* At least one descriptor is known to be ready now, so we will
return success. */
err = 0;
}
void
_hurdsig_fault_init (void)
{
error_t err;
struct machine_thread_state state;
mach_port_t sigexc;
/* Allocate a port to receive signal thread exceptions.
We will move this receive right to the proc server. */
err = __mach_port_allocate (__mach_task_self (),
MACH_PORT_RIGHT_RECEIVE, &sigexc);
assert_perror (err);
err = __mach_port_allocate (__mach_task_self (),
MACH_PORT_RIGHT_RECEIVE, &forward_sigexc);
assert_perror (err);
/* Allocate a port to receive the exception msgs forwarded
from the proc server. */
err = __mach_port_insert_right (__mach_task_self (), sigexc,
sigexc, MACH_MSG_TYPE_MAKE_SEND);
assert_perror (err);
/* Set the queue limit for this port to just one. The proc server will
notice if we ever get a second exception while one remains queued and
unreceived, and decide we are hopelessly buggy. */
#ifdef MACH_PORT_RECEIVE_STATUS_COUNT
{
const mach_port_limits_t lim = { mpl_qlimit: 1 };
assert (MACH_PORT_RECEIVE_STATUS_COUNT == sizeof lim / sizeof (natural_t));
err = __mach_port_set_attributes (__mach_task_self (), forward_sigexc,
MACH_PORT_RECEIVE_STATUS,
(mach_port_info_t) &lim,
MACH_PORT_RECEIVE_STATUS_COUNT);
}
#else
err = __mach_port_set_qlimit (__mach_task_self (), forward_sigexc, 1);
#endif
assert_perror (err);
/* This state will be restored when we fault.
It runs the function above. */
memset (&state, 0, sizeof state);
MACHINE_THREAD_STATE_SET_PC (&state, faulted);
MACHINE_THREAD_STATE_SET_SP (&state, faultstack, sizeof faultstack);
err = __USEPORT
(PROC,
__proc_handle_exceptions (port,
sigexc,
forward_sigexc, MACH_MSG_TYPE_MAKE_SEND,
MACHINE_THREAD_STATE_FLAVOR,
(natural_t *) &state,
MACHINE_THREAD_STATE_COUNT));
assert_perror (err);
/* Direct signal thread exceptions to the proc server. */
#ifdef THREAD_EXCEPTION_PORT
err = __thread_set_special_port (_hurd_msgport_thread,
THREAD_EXCEPTION_PORT, sigexc);
#elif defined (EXC_MASK_ALL)
__thread_set_exception_ports (_hurd_msgport_thread,
EXC_MASK_ALL & ~(EXC_MASK_SYSCALL
| EXC_MASK_MACH_SYSCALL
| EXC_MASK_RPC_ALERT),
sigexc,
EXCEPTION_STATE_IDENTITY,
MACHINE_THREAD_STATE);
#else
# error thread_set_exception_ports?
#endif
__mach_port_deallocate (__mach_task_self (), sigexc);
assert_perror (err);
}
