1 /* Fault handler information. MacOSX version.
2 Copyright (C) 1993-1999, 2002-2003 Bruno Haible <clisp.org at bruno>
4 Copyright (C) 2003 Paolo Bonzini <gnu.org at bonzini>
6 Used under BSD license with permission from Paolo Bonzini and Bruno Haible,
9 http://sourceforge.net/mailarchive/message.php?msg_name=200503102200.32002.bruno%40clisp.org
11 Modified for Factor by Slava Pestov */
18 /* The exception port on which our thread listens. */
19 mach_port_t our_exception_port;
21 /* The following sources were used as a *reference* for this exception handling
23 1. Apple's mach/xnu documentation
24 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
25 omnigroup's macosx-dev list.
26 http://www.wodeveloper.com/omniLists/macosx-dev/2000/June/msg00137.html */
28 /* Modify a suspended thread's thread_state so that when the thread resumes
29 executing, the call frame of the current C primitive (if any) is rewound, and
30 the appropriate Factor error is thrown from the top-most Factor frame. */
31 void factor_vm::call_fault_handler(
32 exception_type_t exception,
33 exception_data_type_t code,
34 MACH_EXC_STATE_TYPE *exc_state,
35 MACH_THREAD_STATE_TYPE *thread_state,
36 MACH_FLOAT_STATE_TYPE *float_state)
40 if(exception == EXC_BAD_ACCESS)
42 signal_fault_addr = MACH_EXC_STATE_FAULT(exc_state);
43 signal_fault_pc = (cell)MACH_PROGRAM_COUNTER(thread_state);
44 verify_memory_protection_error(signal_fault_addr);
45 handler = (cell)factor::memory_signal_handler_impl;
47 else if(exception == EXC_ARITHMETIC && code != MACH_EXC_INTEGER_DIV)
49 signal_fpu_status = fpu_status(mach_fpu_status(float_state));
50 mach_clear_fpu_status(float_state);
51 handler = (cell)factor::fp_signal_handler_impl;
57 case EXC_ARITHMETIC: signal_number = SIGFPE; break;
58 case EXC_BAD_INSTRUCTION: signal_number = SIGILL; break;
59 default: signal_number = SIGABRT; break;
62 handler = (cell)factor::synchronous_signal_handler_impl;
65 FACTOR_ASSERT(handler != 0);
67 dispatch_signal_handler(
68 (cell*)&MACH_STACK_POINTER(thread_state),
69 (cell*)&MACH_PROGRAM_COUNTER(thread_state),
74 static void call_fault_handler(
76 exception_type_t exception,
77 exception_data_type_t code,
78 MACH_EXC_STATE_TYPE *exc_state,
79 MACH_THREAD_STATE_TYPE *thread_state,
80 MACH_FLOAT_STATE_TYPE *float_state)
82 /* Look up the VM instance involved */
83 THREADHANDLE thread_id = pthread_from_mach_thread_np(thread);
84 FACTOR_ASSERT(thread_id);
85 std::map<THREADHANDLE, factor_vm*>::const_iterator vm = thread_vms.find(thread_id);
87 /* Handle the exception */
88 if (vm != thread_vms.end())
89 vm->second->call_fault_handler(exception,code,exc_state,thread_state,float_state);
92 /* Handle an exception by invoking the user's fault handler and/or forwarding
93 the duty to the previously installed handlers. */
96 catch_exception_raise (mach_port_t exception_port,
99 exception_type_t exception,
100 exception_data_t code,
101 mach_msg_type_number_t code_count)
103 /* 10.6 likes to report exceptions from child processes too. Ignore those */
104 if(task != mach_task_self()) return KERN_FAILURE;
106 /* Get fault information and the faulting thread's register contents..
108 See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/thread_get_state.html. */
109 MACH_EXC_STATE_TYPE exc_state;
110 mach_msg_type_number_t exc_state_count = MACH_EXC_STATE_COUNT;
111 if (thread_get_state (thread, MACH_EXC_STATE_FLAVOR,
112 (natural_t *)&exc_state, &exc_state_count)
115 /* The thread is supposed to be suspended while the exception
116 handler is called. This shouldn't fail. */
120 MACH_THREAD_STATE_TYPE thread_state;
121 mach_msg_type_number_t thread_state_count = MACH_THREAD_STATE_COUNT;
122 if (thread_get_state (thread, MACH_THREAD_STATE_FLAVOR,
123 (natural_t *)&thread_state, &thread_state_count)
126 /* The thread is supposed to be suspended while the exception
127 handler is called. This shouldn't fail. */
131 MACH_FLOAT_STATE_TYPE float_state;
132 mach_msg_type_number_t float_state_count = MACH_FLOAT_STATE_COUNT;
133 if (thread_get_state (thread, MACH_FLOAT_STATE_FLAVOR,
134 (natural_t *)&float_state, &float_state_count)
137 /* The thread is supposed to be suspended while the exception
138 handler is called. This shouldn't fail. */
142 /* Modify registers so to have the thread resume executing the
144 call_fault_handler(thread,exception,code[0],&exc_state,&thread_state,&float_state);
146 /* Set the faulting thread's register contents..
148 See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/thread_set_state.html. */
149 if (thread_set_state (thread, MACH_FLOAT_STATE_FLAVOR,
150 (natural_t *)&float_state, float_state_count)
156 if (thread_set_state (thread, MACH_THREAD_STATE_FLAVOR,
157 (natural_t *)&thread_state, thread_state_count)
166 /* The main function of the thread listening for exceptions. */
168 mach_exception_thread (void *arg)
172 /* These two structures contain some private kernel data. We don't need
173 to access any of it so we don't bother defining a proper struct. The
174 correct definitions are in the xnu source code. */
175 /* Buffer for a message to be received. */
178 mach_msg_header_t head;
179 mach_msg_body_t msgh_body;
183 /* Buffer for a reply message. */
186 mach_msg_header_t head;
191 mach_msg_return_t retval;
193 /* Wait for a message on the exception port. */
194 retval = mach_msg (&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0,
195 sizeof (msg), our_exception_port,
196 MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
197 if (retval != MACH_MSG_SUCCESS)
202 /* Handle the message: Call exc_server, which will call
203 catch_exception_raise and produce a reply message. */
204 exc_server (&msg.head, &reply.head);
206 /* Send the reply. */
207 if (mach_msg (&reply.head, MACH_SEND_MSG, reply.head.msgh_size,
208 0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL)
214 return NULL; // quiet warning
217 /* Initialize the Mach exception handler thread. */
218 void mach_initialize ()
221 exception_mask_t mask;
223 self = mach_task_self ();
225 /* Allocate a port on which the thread shall listen for exceptions. */
226 if (mach_port_allocate (self, MACH_PORT_RIGHT_RECEIVE, &our_exception_port)
228 fatal_error("mach_port_allocate() failed",0);
230 /* See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/mach_port_insert_right.html. */
231 if (mach_port_insert_right (self, our_exception_port, our_exception_port,
232 MACH_MSG_TYPE_MAKE_SEND)
234 fatal_error("mach_port_insert_right() failed",0);
236 /* The exceptions we want to catch. */
237 mask = EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC;
239 /* Create the thread listening on the exception port. */
240 start_thread(mach_exception_thread,NULL);
242 /* Replace the exception port info for these exceptions with our own.
243 Note that we replace the exception port for the entire task, not only
244 for a particular thread. This has the effect that when our exception
245 port gets the message, the thread specific exception port has already
246 been asked, and we don't need to bother about it.
247 See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/task_set_exception_ports.html. */
248 if (task_set_exception_ports (self, mask, our_exception_port,
249 EXCEPTION_DEFAULT, MACHINE_THREAD_STATE)
251 fatal_error("task_set_exception_ports() failed",0);