void
exception_try_task(
integer_t _exception,
integer_t code,
integer_t subcode)
{
ipc_thread_t self = current_thread();
task_t task = self->task;
ipc_port_t exc_port;
/*
* Optimized version of retrieve_task_exception.
*/
itk_lock(task);
assert(task->itk_self != IP_NULL);
exc_port = task->itk_exception;
if (!IP_VALID(exc_port)) {
itk_unlock(task);
exception_no_server();
/*NOTREACHED*/
}
ip_lock(exc_port);
itk_unlock(task);
if (!ip_active(exc_port)) {
ip_unlock(exc_port);
exception_no_server();
/*NOTREACHED*/
}
/*
* Make a naked send right for the exception port.
*/
ip_reference(exc_port);
exc_port->ip_srights++;
ip_unlock(exc_port);
/*
* This is the thread's last chance.
* Clear the saved exception state.
*/
self->ith_exc = KERN_SUCCESS;
exception_raise(exc_port,
retrieve_thread_self_fast(self),
retrieve_task_self_fast(task),
_exception, code, subcode);
/*NOTREACHED*/
}
/*
* Routine: exception_deliver
* Purpose:
* Make an upcall to the exception server provided.
* Conditions:
* Nothing locked and no resources held.
* Called from an exception context, so
* thread_exception_return and thread_kdb_return
* are possible.
* Returns:
* KERN_SUCCESS if the exception was handled
*/
kern_return_t
exception_deliver(
thread_t thread,
exception_type_t exception,
mach_exception_data_t code,
mach_msg_type_number_t codeCnt,
struct exception_action *excp,
lck_mtx_t *mutex)
{
ipc_port_t exc_port;
exception_data_type_t small_code[EXCEPTION_CODE_MAX];
int code64;
int behavior;
int flavor;
kern_return_t kr;
/*
* Save work if we are terminating.
* Just go back to our AST handler.
*/
if (!thread->active)
return KERN_SUCCESS;
/*
* Snapshot the exception action data under lock for consistency.
* Hold a reference to the port over the exception_raise_* calls
* so it can't be destroyed. This seems like overkill, but keeps
* the port from disappearing between now and when
* ipc_object_copyin_from_kernel is finally called.
*/
lck_mtx_lock(mutex);
exc_port = excp->port;
if (!IP_VALID(exc_port)) {
lck_mtx_unlock(mutex);
return KERN_FAILURE;
}
ip_lock(exc_port);
if (!ip_active(exc_port)) {
ip_unlock(exc_port);
lck_mtx_unlock(mutex);
return KERN_FAILURE;
}
ip_reference(exc_port);
exc_port->ip_srights++;
ip_unlock(exc_port);
flavor = excp->flavor;
behavior = excp->behavior;
lck_mtx_unlock(mutex);
code64 = (behavior & MACH_EXCEPTION_CODES);
behavior &= ~MACH_EXCEPTION_CODES;
if (!code64) {
small_code[0] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[0]);
small_code[1] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[1]);
}
switch (behavior) {
case EXCEPTION_STATE: {
mach_msg_type_number_t state_cnt;
thread_state_data_t state;
c_thr_exc_raise_state++;
state_cnt = _MachineStateCount[flavor];
kr = thread_getstatus(thread, flavor,
(thread_state_t)state,
&state_cnt);
if (kr == KERN_SUCCESS) {
if (code64) {
kr = mach_exception_raise_state(exc_port,
exception,
code,
codeCnt,
&flavor,
state, state_cnt,
state, &state_cnt);
} else {
kr = exception_raise_state(exc_port, exception,
small_code,
codeCnt,
&flavor,
state, state_cnt,
state, &state_cnt);
}
if (kr == MACH_MSG_SUCCESS)
kr = thread_setstatus(thread, flavor,
(thread_state_t)state,
state_cnt);
}
return kr;
}
case EXCEPTION_DEFAULT:
c_thr_exc_raise++;
if (code64) {
kr = mach_exception_raise(exc_port,
retrieve_thread_self_fast(thread),
retrieve_task_self_fast(thread->task),
exception,
code,
codeCnt);
} else {
kr = exception_raise(exc_port,
retrieve_thread_self_fast(thread),
retrieve_task_self_fast(thread->task),
exception,
small_code,
codeCnt);
}
return kr;
case EXCEPTION_STATE_IDENTITY: {
mach_msg_type_number_t state_cnt;
thread_state_data_t state;
c_thr_exc_raise_state_id++;
state_cnt = _MachineStateCount[flavor];
kr = thread_getstatus(thread, flavor,
(thread_state_t)state,
&state_cnt);
if (kr == KERN_SUCCESS) {
if (code64) {
kr = mach_exception_raise_state_identity(
exc_port,
retrieve_thread_self_fast(thread),
retrieve_task_self_fast(thread->task),
exception,
code,
codeCnt,
&flavor,
state, state_cnt,
state, &state_cnt);
} else {
kr = exception_raise_state_identity(exc_port,
retrieve_thread_self_fast(thread),
retrieve_task_self_fast(thread->task),
exception,
small_code,
codeCnt,
&flavor,
state, state_cnt,
state, &state_cnt);
}
if (kr == MACH_MSG_SUCCESS)
kr = thread_setstatus(thread, flavor,
(thread_state_t)state,
state_cnt);
}
return kr;
}
default:
panic ("bad exception behavior!");
return KERN_FAILURE;
}/* switch */
}