/vm/mach_signal.cpp
C++ | 231 lines | 137 code | 32 blank | 62 comment | 26 complexity | 1cc94ef13445c0902b98256ba6abeab1 MD5 | raw file
- /* Fault handler information. MacOSX version.
- Copyright (C) 1993-1999, 2002-2003 Bruno Haible <clisp.org at bruno>
- Copyright (C) 2003 Paolo Bonzini <gnu.org at bonzini>
- Used under BSD license with permission from Paolo Bonzini and Bruno Haible,
- 2005-03-10:
- http://sourceforge.net/mailarchive/message.php?msg_name=200503102200.32002.bruno%40clisp.org
- Modified for Factor by Slava Pestov */
- #include "master.hpp"
- namespace factor {
- /* The exception port on which our thread listens. */
- mach_port_t our_exception_port;
- /* The following sources were used as a *reference* for this exception handling
- code:
- 1. Apple's mach/xnu documentation
- 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
- omnigroup's macosx-dev list.
- http://www.wodeveloper.com/omniLists/macosx-dev/2000/June/msg00137.html */
- /* Modify a suspended thread's thread_state so that when the thread resumes
- executing, the call frame of the current C primitive (if any) is rewound, and
- the appropriate Factor error is thrown from the top-most Factor frame. */
- void factor_vm::call_fault_handler(exception_type_t exception,
- exception_data_type_t code,
- MACH_EXC_STATE_TYPE* exc_state,
- MACH_THREAD_STATE_TYPE* thread_state,
- MACH_FLOAT_STATE_TYPE* float_state) {
- cell handler = 0;
- if (exception == EXC_BAD_ACCESS) {
- signal_fault_addr = MACH_EXC_STATE_FAULT(exc_state);
- signal_fault_pc = (cell)MACH_PROGRAM_COUNTER(thread_state);
- verify_memory_protection_error(signal_fault_addr);
- handler = (cell)factor::memory_signal_handler_impl;
- } else if (exception == EXC_ARITHMETIC && code != MACH_EXC_INTEGER_DIV) {
- signal_fpu_status = fpu_status(mach_fpu_status(float_state));
- mach_clear_fpu_status(float_state);
- handler = (cell)factor::fp_signal_handler_impl;
- } else {
- switch (exception) {
- case EXC_ARITHMETIC:
- signal_number = SIGFPE;
- break;
- case EXC_BAD_INSTRUCTION:
- signal_number = SIGILL;
- break;
- default:
- signal_number = SIGABRT;
- break;
- }
- handler = (cell)factor::synchronous_signal_handler_impl;
- }
- FACTOR_ASSERT(handler != 0);
- dispatch_signal_handler((cell*)&MACH_STACK_POINTER(thread_state),
- (cell*)&MACH_PROGRAM_COUNTER(thread_state),
- (cell)handler);
- }
- static void call_fault_handler(mach_port_t thread, exception_type_t exception,
- exception_data_type_t code,
- MACH_EXC_STATE_TYPE* exc_state,
- MACH_THREAD_STATE_TYPE* thread_state,
- MACH_FLOAT_STATE_TYPE* float_state) {
- /* Look up the VM instance involved */
- THREADHANDLE thread_id = pthread_from_mach_thread_np(thread);
- FACTOR_ASSERT(thread_id);
- std::map<THREADHANDLE, factor_vm*>::const_iterator vm =
- thread_vms.find(thread_id);
- /* Handle the exception */
- if (vm != thread_vms.end())
- vm->second->call_fault_handler(exception, code, exc_state, thread_state,
- float_state);
- }
- /* Handle an exception by invoking the user's fault handler and/or forwarding
- the duty to the previously installed handlers. */
- extern "C" kern_return_t catch_exception_raise(
- mach_port_t exception_port, mach_port_t thread, mach_port_t task,
- exception_type_t exception, exception_data_t code,
- mach_msg_type_number_t code_count) {
- /* 10.6 likes to report exceptions from child processes too. Ignore those */
- if (task != mach_task_self())
- return KERN_FAILURE;
- /* Get fault information and the faulting thread's register contents..
- See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/thread_get_state.html. */
- MACH_EXC_STATE_TYPE exc_state;
- mach_msg_type_number_t exc_state_count = MACH_EXC_STATE_COUNT;
- if (thread_get_state(thread, MACH_EXC_STATE_FLAVOR, (natural_t*)&exc_state,
- &exc_state_count) !=
- KERN_SUCCESS) {
- /* The thread is supposed to be suspended while the exception
- handler is called. This shouldn't fail. */
- return KERN_FAILURE;
- }
- MACH_THREAD_STATE_TYPE thread_state;
- mach_msg_type_number_t thread_state_count = MACH_THREAD_STATE_COUNT;
- if (thread_get_state(thread, MACH_THREAD_STATE_FLAVOR,
- (natural_t*)&thread_state, &thread_state_count) !=
- KERN_SUCCESS) {
- /* The thread is supposed to be suspended while the exception
- handler is called. This shouldn't fail. */
- return KERN_FAILURE;
- }
- MACH_FLOAT_STATE_TYPE float_state;
- mach_msg_type_number_t float_state_count = MACH_FLOAT_STATE_COUNT;
- if (thread_get_state(thread, MACH_FLOAT_STATE_FLAVOR,
- (natural_t*)&float_state, &float_state_count) !=
- KERN_SUCCESS) {
- /* The thread is supposed to be suspended while the exception
- handler is called. This shouldn't fail. */
- return KERN_FAILURE;
- }
- /* Modify registers so to have the thread resume executing the
- fault handler */
- call_fault_handler(thread, exception, code[0], &exc_state, &thread_state,
- &float_state);
- /* Set the faulting thread's register contents..
- See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/thread_set_state.html. */
- if (thread_set_state(thread, MACH_FLOAT_STATE_FLAVOR,
- (natural_t*)&float_state, float_state_count) !=
- KERN_SUCCESS) {
- return KERN_FAILURE;
- }
- if (thread_set_state(thread, MACH_THREAD_STATE_FLAVOR,
- (natural_t*)&thread_state, thread_state_count) !=
- KERN_SUCCESS) {
- return KERN_FAILURE;
- }
- return KERN_SUCCESS;
- }
- /* 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
- }
- /* Initialize the Mach exception handler thread. */
- void mach_initialize() {
- mach_port_t self;
- exception_mask_t mask;
- self = mach_task_self();
- /* Allocate a port on which the thread shall listen for exceptions. */
- if (mach_port_allocate(self, MACH_PORT_RIGHT_RECEIVE, &our_exception_port) !=
- KERN_SUCCESS)
- fatal_error("mach_port_allocate() failed", 0);
- /* See
- * http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/mach_port_insert_right.html.
- */
- if (mach_port_insert_right(self, our_exception_port, our_exception_port,
- MACH_MSG_TYPE_MAKE_SEND) !=
- KERN_SUCCESS)
- fatal_error("mach_port_insert_right() failed", 0);
- /* The exceptions we want to catch. */
- mask = EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC;
- /* Create the thread listening on the exception port. */
- start_thread(mach_exception_thread, NULL);
- /* Replace the exception port info for these exceptions with our own.
- Note that we replace the exception port for the entire task, not only
- for a particular thread. This has the effect that when our exception
- port gets the message, the thread specific exception port has already
- been asked, and we don't need to bother about it. See
- http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/task_set_exception_ports.html. */
- if (task_set_exception_ports(self, mask, our_exception_port,
- EXCEPTION_DEFAULT, MACHINE_THREAD_STATE) !=
- KERN_SUCCESS)
- fatal_error("task_set_exception_ports() failed", 0);
- }
- }