error_t
hurd_thread_cancel (thread_t thread)
{
struct hurd_sigstate *ss = _hurd_thread_sigstate (thread);
struct machine_thread_all_state state;
int state_change;
error_t err;
if (! ss)
return EINVAL;
if (ss == _hurd_self_sigstate ())
{
/* We are cancelling ourselves, so it is easy to succeed
quickly. Since this function is not a cancellation point, we
just leave the flag set pending the next cancellation point
(hurd_check_cancel or RPC) and return success. */
ss->cancel = 1;
return 0;
}
assert (! __spin_lock_locked (&ss->critical_section_lock));
__spin_lock (&ss->critical_section_lock);
__spin_lock (&ss->lock);
err = __thread_suspend (thread);
__spin_unlock (&ss->lock);
if (! err)
{
/* Set the flag telling the thread its operation is being cancelled. */
ss->cancel = 1;
/* Interrupt any interruptible RPC now in progress. */
state.set = 0;
_hurdsig_abort_rpcs (ss, 0, 0, &state, &state_change, NULL, 0, 0);
if (state_change)
err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
(natural_t *) &state.basic,
MACHINE_THREAD_STATE_COUNT);
if (ss->cancel_hook)
/* The code being cancelled has a special wakeup function.
Calling this should make the thread wake up and check the
cancellation flag. */
(*ss->cancel_hook) ();
__thread_resume (thread);
}
_hurd_critical_section_unlock (ss);
return err;
}
int
hurd_check_cancel (void)
{
struct hurd_sigstate *ss = _hurd_self_sigstate ();
int cancel;
__spin_lock (&ss->lock);
assert (! __spin_lock_locked (&ss->critical_section_lock));
cancel = ss->cancel;
ss->cancel = 0;
__spin_unlock (&ss->lock);
return cancel;
}
kern_return_t
_S_catch_exception_raise (mach_port_t port,
thread_t thread,
task_t task,
int exception,
int code,
int subcode)
{
int signo, sigcode, error;
struct hurd_sigstate *ss;
if (task != __mach_task_self ())
/* The sender wasn't the kernel. */
return EPERM;
/* Call the machine-dependent function to translate the Mach exception
codes into a signal number and subcode. */
_hurd_exception2signal (exception, code, subcode,
&signo, &sigcode, &error);
/* Find the sigstate structure for the faulting thread. */
__mutex_lock (&_hurd_siglock);
for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
if (ss->thread == thread)
break;
__mutex_unlock (&_hurd_siglock);
if (ss == NULL)
ss = _hurd_thread_sigstate (thread); /* Allocate a fresh one. */
if (__spin_lock_locked (&ss->lock.held))
/* Oops. The thread faulted with its sigstate lock held.
Bad scene. What to do? */
; /* XXX */
else
__mutex_lock (&ss->lock);
/* Post the signal. */
_hurd_internal_post_signal (ss, signo, sigcode, error,
MACH_PORT_NULL, MACH_MSG_TYPE_PORT_SEND);
return KERN_SUCCESS;
}
void
_longjmp_unwind (jmp_buf env, int val)
{
struct hurd_sigstate *ss = _hurd_self_sigstate ();
struct hurd_userlink *link;
/* All access to SS->active_resources must take place inside a critical
section where signal handlers cannot run. */
__spin_lock (&ss->lock);
assert (! __spin_lock_locked (&ss->critical_section_lock));
__spin_lock (&ss->critical_section_lock);
/* Remove local signal preemptors being unwound past. */
while (ss->preemptors &&
_JMPBUF_UNWINDS (env[0].__jmpbuf, ss->preemptors, demangle_ptr))
ss->preemptors = ss->preemptors->next;
__spin_unlock (&ss->lock);
/* Iterate over the current thread's list of active resources.
Process the head portion of the list whose links reside
in stack frames being unwound by this jump. */
for (link = ss->active_resources;
link && _JMPBUF_UNWINDS (env[0].__jmpbuf, link, demangle_ptr);
link = link->thread.next)
/* Remove this link from the resource's users list,
since the frame using the resource is being unwound.
This call returns nonzero if that was the last user. */
if (_hurd_userlink_unlink (link))
/* One of the frames being unwound by the longjmp was the last user
of its resource. Call the cleanup function to deallocate it. */
(*link->cleanup) (link->cleanup_data, env, val);
_hurd_critical_section_unlock (ss);
}
kern_return_t
_S_catch_exception_raise (mach_port_t port,
thread_t thread,
task_t task,
#ifdef EXC_MASK_ALL /* New interface flavor. */
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t codeCnt
#else /* Vanilla Mach 3.0 interface. */
integer_t exception,
integer_t code, integer_t subcode
#endif
)
{
struct hurd_sigstate *ss;
int signo;
struct hurd_signal_detail d;
if (task != __mach_task_self ())
/* The sender wasn't the kernel. */
return EPERM;
d.exc = exception;
#ifdef EXC_MASK_ALL
assert (codeCnt >= 2);
d.exc_code = code[0];
d.exc_subcode = code[1];
#else
d.exc_code = code;
d.exc_subcode = subcode;
#endif
/* Call the machine-dependent function to translate the Mach exception
codes into a signal number and subcode. */
_hurd_exception2signal (&d, &signo);
/* Find the sigstate structure for the faulting thread. */
__mutex_lock (&_hurd_siglock);
for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
if (ss->thread == thread)
break;
__mutex_unlock (&_hurd_siglock);
if (ss == NULL)
ss = _hurd_thread_sigstate (thread); /* Allocate a fresh one. */
if (__spin_lock_locked (&ss->lock))
{
/* Loser. The thread faulted with its sigstate lock held. Its
sigstate data is now suspect. So we reset the parts of it which
could cause trouble for the signal thread. Anything else
clobbered therein will just hose this user thread, but it's
faulting already.
This is almost certainly a library bug: unless random memory
clobberation caused the sigstate lock to gratuitously appear held,
no code should do anything that can fault while holding the
sigstate lock. */
__spin_unlock (&ss->critical_section_lock);
ss->context = NULL;
__spin_unlock (&ss->lock);
}
/* Post the signal. */
_hurd_internal_post_signal (ss, signo, &d,
MACH_PORT_NULL, MACH_MSG_TYPE_PORT_SEND,
0);
return KERN_SUCCESS;
}
mach_port_t port = *reply_port;
/* Assigning MACH_PORT_DEAD here tells libc's mig_get_reply_port
not to get another reply port, but avoids mig_dealloc_reply_port
trying to deallocate it after the receive fails (which it will,
because the reply port will be bogus, regardless). */
*reply_port = MACH_PORT_DEAD;
__mach_port_destroy (__mach_task_self (), port);
}
if (scp->sc_reply_port)
__mach_port_destroy (__mach_task_self (), scp->sc_reply_port);
}
__spin_lock (&ss->lock);
/* We should only ever be called from _longjmp_unwind (in jmp-unwind.c),
which calls us inside a critical section. */
assert (__spin_lock_locked (&ss->critical_section_lock));
/* Are we on the alternate signal stack now? */
onstack = (ss->sigaltstack.ss_flags & SS_ONSTACK);
__spin_unlock (&ss->lock);
if (onstack && ! scp->sc_onstack)
{
/* We are unwinding off the signal stack. We must use sigreturn to
do it robustly. Mutate the sigcontext so that when sigreturn
resumes from that context, it will be as if `__longjmp (ENV, VAL)'
were done. */
struct hurd_userlink *link;
inline uintptr_t demangle_ptr (uintptr_t x)
{
/* 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;
}
