/* this is the thread which forwards of exceptions read from the exception
server off to our exception catchers and then back out to the other
thread */
void exception_thread(void *shared_thread_state)
{
mach_msg_header_t *message;
mach_msg_header_t *reply;
kern_return_t retval;
#ifdef USE_THREAD_LOCAL
pthread_setspecific(scheme_thread_local_key, shared_thread_state);
#endif
/* allocate the space for the message and reply */
message = (mach_msg_header_t*)malloc(sizeof(mach_exc_msg_t));
reply = (mach_msg_header_t*)malloc(sizeof(mach_reply_msg_t));
/* do this loop forever */
while(1) {
/* block until we get an exception message */
retval = mach_msg(message, MACH_RCV_MSG, 0, sizeof(mach_exc_msg_t),
exc_port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
/* forward off the handling of this message */
if(!exc_server(message, reply)) {
GCPRINT(GCOUTF, "INTERNAL ERROR: exc_server() didn't like something\n");
abort();
}
/* send the message back out to the thread */
retval = mach_msg(reply, MACH_SEND_MSG, sizeof(mach_reply_msg_t), 0,
MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
}
}
/*
* This message server catches server exceptions. It runs in a dedicated thread.
*/
void *
server_exception_catcher(
void *arg)
{
struct server_thread_priv_data priv_data;
kern_return_t kr;
#define MSG_BUFFER_SIZE 8192
union request_msg {
mach_msg_header_t hdr;
mig_reply_error_t death_pill;
char space[MSG_BUFFER_SIZE];
} *msg_buffer_1, *msg_buffer_2;
mach_msg_header_t *request;
mig_reply_error_t *reply;
cthread_set_name(cthread_self(), "server exc catcher");
server_thread_set_priv_data(cthread_self(), &priv_data);
kr = vm_allocate(mach_task_self(),
(vm_address_t *) &msg_buffer_1,
2 * sizeof *msg_buffer_1,
TRUE);
if (kr != KERN_SUCCESS) {
MACH3_DEBUG(0, kr, ("server_exception_catcher: vm_allocate"));
panic("server_exception_catcher");
}
msg_buffer_2 = msg_buffer_1 + 1;
request = &msg_buffer_1->hdr;
reply = &msg_buffer_2->death_pill;
do {
kr = mach_msg(request, MACH_RCV_MSG,
0, sizeof *msg_buffer_1,
server_exception_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (kr != MACH_MSG_SUCCESS) {
MACH3_DEBUG(1, kr,
("server_exception_catcher: mach_msg"));
panic("server_exception_catcher: receive");
}
if (exc_server(request, &reply->Head)) {}
else {
printk("server_exception_catcher: invalid message"
"(id = %d = 0x%x)\n",
request->msgh_id, request->msgh_id);
}
panic("server_exception_catcher: what now ?");
} while (1);
cthread_detach(cthread_self());
cthread_exit((void *) 0);
/*NOTREACHED*/
return (void *) 0;
}
static any_t exc_thread(ports_t *port_p)
{
kern_return_t r;
char *msg_data[2][64];
msg_header_t *imsg = (msg_header_t *)msg_data[0],
*omsg = (msg_header_t *)msg_data[1];
/* Wait for exceptions */
while(1) {
imsg->msg_size = 64;
imsg->msg_local_port = port_p->exc_port;
r = msg_receive(imsg, MSG_OPTION_NONE, 0);
if (r == RCV_SUCCESS) {
/* Give the message to the Mach exception server. */
if (exc_server(imsg,omsg)) {
/* send the reply message that exc_serv gave us. */
r = msg_send(omsg, MSG_OPTION_NONE, 0);
if (r != SEND_SUCCESS) {
mach_error("exc_thread msg_send",r);
exit(1);
}
}
else {
/* exc_server refused to handle the imsg. */
exit(2);
}
}
else {
/* msg_receive returned an error. */
mach_error("exc_thread msg_receive",r);
exit(3);
}
/* Pass the message to the old exception handler, if necessary. */
if (pass_on == TRUE) {
imsg->msg_remote_port = port_p->old_exc_port;
imsg->msg_local_port = port_p->clear_port;
r = msg_send(imsg, MSG_OPTION_NONE, 0);
if (r != SEND_SUCCESS) {
mach_error("msg_send to old_exc_port",r);
exit(4);
}
}
}
}
/* FUNCTIONS */
static void *exc_thread(void *junk) {
mach_msg_return_t r;
/*
These two structures contain some private kernel data. We don't need to
access any of it so we don't bother defining a proper struct. The
correct definitions are in the xnu source code.
*/
struct {
mach_msg_header_t head;
char data[256];
} reply;
struct {
mach_msg_header_t head;
mach_msg_body_t msgh_body;
char data[1024];
} msg;
for(;;) {
r = mach_msg(
&msg.head,
MACH_RCV_MSG|MACH_RCV_LARGE,
0,
sizeof(msg),
exception_port,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if(r != MACH_MSG_SUCCESS) DIE("mach_msg");
/* Handle the message (calls catch_exception_raise) */
if(!exc_server(&msg.head,&reply.head)) DIE("exc_server");
/* Send the reply */
r = mach_msg(
&reply.head,
MACH_SEND_MSG,
reply.head.msgh_size,
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if(r != MACH_MSG_SUCCESS) DIE("mach_msg");
}
/* not reached */
}
/*
* Exception thread handler.
*/
static
void *
mach_exception_thread (void *arg)
{
for (;;) {
mach_exception_msg_t request;
mach_exception_msg_t reply;
mach_msg_return_t result;
/* receive from "mach_exception_port" */
result = mach_msg (&request.msg.header,
MACH_RCV_MSG | MACH_RCV_LARGE,
0,
sizeof (request),
mach_exception_port,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
g_assert (result == MACH_MSG_SUCCESS);
/* dispatch to catch_exception_raise () */
exc_server (&request.msg.header, &reply.msg.header);
/* send back to sender */
result = mach_msg (&reply.msg.header,
MACH_SEND_MSG,
reply.msg.header.msgh_size,
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
/*
If we try to abort the thread while delivering an exception. The port will be gone since the kernel
setup a send once port to deliver the resume message and thread_abort will consume it.
*/
g_assert (result == MACH_MSG_SUCCESS || result == MACH_SEND_INVALID_DEST);
}
return NULL;
}
/* The main function of the thread listening for exceptions. */
static void* mach_exception_thread(void* arg) {
for (;;) {
/* These two structures contain some private kernel data. We don't need
to access any of it so we don't bother defining a proper struct. The
correct definitions are in the xnu source code. */
/* Buffer for a message to be received. */
struct {
mach_msg_header_t head;
mach_msg_body_t msgh_body;
char data[1024];
} msg;
/* Buffer for a reply message. */
struct {
mach_msg_header_t head;
char data[1024];
} reply;
mach_msg_return_t retval;
/* Wait for a message on the exception port. */
retval =
mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0, sizeof(msg),
our_exception_port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (retval != MACH_MSG_SUCCESS) {
abort();
}
/* Handle the message: Call exc_server, which will call
catch_exception_raise and produce a reply message. */
exc_server(&msg.head, &reply.head);
/* Send the reply. */
if (mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0,
MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL) !=
MACH_MSG_SUCCESS) {
abort();
}
}
return NULL; // quiet warning
}
/*
* Exception thread handler.
*/
static
void *
mach_exception_thread (void *arg)
{
for (;;) {
mach_exception_msg_t request;
mach_exception_msg_t reply;
mach_msg_return_t result;
/* receive from "mach_exception_port" */
result = mach_msg (&request.msg.header,
MACH_RCV_MSG | MACH_RCV_LARGE,
0,
sizeof (request),
mach_exception_port,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
g_assert (result == MACH_MSG_SUCCESS);
/* dispatch to catch_exception_raise () */
exc_server (&request.msg.header, &reply.msg.header);
/* send back to sender */
result = mach_msg (&reply.msg.header,
MACH_SEND_MSG,
reply.msg.header.msgh_size,
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
g_assert (result == MACH_MSG_SUCCESS);
}
return NULL;
}
void *ExceptionHandlerThread(void *thread_arg) {
mach_port_t handler_port = (mach_port_t) (uintptr_t) thread_arg;
while (1) {
struct {
mach_msg_header_t header;
uint8_t data[256];
} receive;
mach_msg_header_t reply;
kern_return_t rc;
receive.header.msgh_local_port = handler_port;
receive.header.msgh_size = sizeof(receive);
rc = mach_msg(&receive.header,
MACH_RCV_MSG | MACH_RCV_LARGE, 0,
receive.header.msgh_size, handler_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
CHECK(rc == KERN_SUCCESS);
CHECK(exc_server(&receive.header, &reply));
exit(1);
}
return NULL;
}
static void *mach_exception_thread(void *data) {
while (true) {
struct {
mach_msg_header_t head;
mach_msg_body_t msgh_body;
char data[1024];
} msg;
struct {
mach_msg_header_t head;
char data[1024];
} reply;
// wait for a message on the exception port
mach_msg_return_t ret =
mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0, sizeof(msg),
s_listen_port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (ret != MACH_MSG_SUCCESS) {
LOG_INFO("mach_msg receive failed with %d %s", ret,
mach_error_string(ret));
break;
}
// call exc_server, which will call back into catch_exception_raise
exc_server(&msg.head, &reply.head);
// send the reply
ret = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0,
MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (ret != MACH_MSG_SUCCESS) {
LOG_INFO("mach_msg send failed with %d %s", ret, mach_error_string(ret));
break;
}
}
return NULL;
}
/*
* This message server catches user task exceptions. Most user exceptions
* will be received on the thread exception port. This server servers
* only exceptions from unknown threads or from external debuggers.
* It runs in a dedicated thread.
*/
void *
task_exception_catcher(
void *arg)
{
struct server_thread_priv_data priv_data;
kern_return_t kr;
#define MSG_BUFFER_SIZE 8192
union request_msg {
mach_msg_header_t hdr;
mig_reply_error_t death_pill;
char space[MSG_BUFFER_SIZE];
} *msg_buffer_1, *msg_buffer_2;
mach_msg_header_t *request;
mig_reply_error_t *reply;
mach_msg_header_t *tmp;
cthread_set_name(cthread_self(), "task exc catcher");
server_thread_set_priv_data(cthread_self(), &priv_data);
uniproc_enter();
kr = vm_allocate(mach_task_self(),
(vm_address_t *) &msg_buffer_1,
2 * sizeof *msg_buffer_1,
TRUE);
if (kr != KERN_SUCCESS) {
MACH3_DEBUG(0, kr, ("task_exception_catcher: vm_allocate"));
panic("task_exception_catcher");
}
msg_buffer_2 = msg_buffer_1 + 1;
request = &msg_buffer_1->hdr;
reply = &msg_buffer_2->death_pill;
do {
uniproc_exit();
kr = mach_msg(request, MACH_RCV_MSG,
0, sizeof *msg_buffer_1,
user_trap_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (kr != MACH_MSG_SUCCESS) {
MACH3_DEBUG(1, kr,
("task_exception_catcher: mach_msg"));
panic("task_exception_catcher: receive");
}
uniproc_enter();
if (exc_server(request, &reply->Head)) {}
else {
printk("trap_exception_catcher: invalid message"
"(id = %d = 0x%x)\n",
request->msgh_id, request->msgh_id);
}
if (reply->Head.msgh_remote_port == MACH_PORT_NULL) {
/* no reply port, just get another request */
continue;
}
if (!(reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
reply->RetCode == MIG_NO_REPLY) {
/* deallocate reply port right */
(void) mach_port_deallocate(mach_task_self(),
reply->Head.msgh_remote_port);
continue;
}
/* Send reply to request and receive another */
uniproc_exit();
kr = mach_msg(&reply->Head,
MACH_SEND_MSG,
reply->Head.msgh_size,
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
uniproc_enter();
if (kr != MACH_MSG_SUCCESS) {
if (kr == MACH_SEND_INVALID_DEST) {
/* deallocate reply port right */
/* XXX should destroy reply msg */
(void) mach_port_deallocate(mach_task_self(),
reply->Head.msgh_remote_port);
} else {
MACH3_DEBUG(0, kr, ("mach_msg"));
panic("task_exception_catcher: send");
}
}
tmp = request;
request = (mach_msg_header_t *) reply;
reply = (mig_reply_error_t *) tmp;
} while (1);
cthread_detach(cthread_self());
cthread_exit((void *) 0);
/*NOTREACHED*/
return (void *) 0;
}
/*++
Function :
SEHExceptionThread
Entry point for the thread that will listen for exception in any other thread.
Parameters :
void *args - not used
Return value :
Never returns
--*/
void *SEHExceptionThread(void *args)
{
mach_msg_return_t MachRet;
// Handle exceptions forever.
while (1)
{
char buf[512];
mach_msg_header_t *msg = (mach_msg_header_t *)buf;
MachRet = mach_msg(msg,
MACH_RCV_MSG | MACH_RCV_LARGE,
0,
sizeof(buf),
s_ExceptionPort,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if (MachRet == MACH_RCV_TOO_LARGE)
{
UTIL_SetLastErrorFromMach(MachRet);
ExitProcess(GetLastError());
}
if (MachRet != MACH_MSG_SUCCESS)
{
UTIL_SetLastErrorFromMach(MachRet);
ExitProcess(GetLastError());
}
if (msg->msgh_id == SET_THREAD_MESSAGE_ID)
{
MSG_SET_THREAD *MsgSet = (MSG_SET_THREAD *)msg;
MachRet = thread_suspend(MsgSet->m_ThreadPort);
if (MachRet != KERN_SUCCESS)
{
UTIL_SetLastErrorFromMach(MachRet);
ExitProcess(GetLastError());
}
if (!CONTEXT_SetThreadContextOnPort(MsgSet->m_ThreadPort, &MsgSet->m_ThreadContext))
{
ExitProcess(GetLastError());
}
MachRet = thread_resume(MsgSet->m_ThreadPort);
if (MachRet != KERN_SUCCESS)
{
UTIL_SetLastErrorFromMach(MachRet);
ExitProcess(GetLastError());
}
}
else
{
char *MsgReply[512];
mach_msg_header_t *reply = (mach_msg_header_t *)MsgReply;
// Pass the message to exc_server which in turn calls catch_exception_raise
exc_server(msg, reply);
// Send the reply message back
MachRet = mach_msg(reply,
MACH_SEND_MSG | MACH_MSG_OPTION_NONE,
reply->msgh_size,
0,
MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if (MachRet != KERN_SUCCESS)
{
UTIL_SetLastErrorFromMach(MachRet);
ExitProcess(GetLastError());
}
}
} // Check for more errors
}
/* The main function of the thread listening for exceptions. */
static void *
mach_exception_thread (void *arg)
{
for (;;)
{
/* These two structures contain some private kernel data. We don't need
to access any of it so we don't bother defining a proper struct. The
correct definitions are in the xnu source code. */
/* Buffer for a message to be received. */
struct
{
mach_msg_header_t head;
mach_msg_body_t msgh_body;
char data[1024];
}
msg;
/* Buffer for a reply message. */
struct
{
mach_msg_header_t head;
char data[1024];
}
reply;
mach_msg_return_t retval;
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "Exception thread going to sleep\n");
#endif
/* Wait for a message on the exception port. */
retval = mach_msg (&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0,
sizeof (msg), our_exception_port,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "Exception thread woke up\n");
#endif
if (retval != MACH_MSG_SUCCESS)
{
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "mach_msg receive failed with %d %s\n",
(int) retval, mach_error_string (retval));
#endif
abort ();
}
/* Handle the message: Call exc_server, which will call
catch_exception_raise and produce a reply message. */
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "Calling exc_server\n");
#endif
exc_server (&msg.head, &reply.head);
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "Finished exc_server\n");
#endif
/* Send the reply. */
if (mach_msg (&reply.head, MACH_SEND_MSG, reply.head.msgh_size,
0, MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL)
!= MACH_MSG_SUCCESS)
{
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "mach_msg send failed\n");
#endif
abort ();
}
#ifdef DEBUG_EXCEPTION_HANDLING
fprintf (stderr, "Reply successful\n");
#endif
}
}
