Updated.
[glibc.git] / hurd / hurdfault.c
blob3c17cc023695bb98fed6c780d2b169761c90b5fa
1 /* Handle faults in the signal thread.
2 Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <hurd.h>
21 #include <hurd/signal.h>
22 #include "hurdfault.h"
23 #include <errno.h>
24 #include <string.h>
25 #include <setjmp.h>
26 #include <stdio.h>
27 #include "thread_state.h"
28 #include "faultexc_server.h" /* mig-generated header for our exc server. */
29 #include <assert.h>
31 jmp_buf _hurdsig_fault_env;
32 struct hurd_signal_preemptor _hurdsig_fault_preemptor = {0};
34 /* XXX temporary to deal with spelling fix */
35 weak_alias (_hurdsig_fault_preemptor, _hurdsig_fault_preempter)
37 static mach_port_t forward_sigexc;
39 kern_return_t
40 _hurdsig_fault_catch_exception_raise (mach_port_t port,
41 thread_t thread,
42 task_t task,
43 int exception,
44 int code,
45 int subcode)
47 int signo;
48 struct hurd_signal_detail d;
50 if (port != forward_sigexc ||
51 thread != _hurd_msgport_thread || task != __mach_task_self ())
52 return EPERM; /* Strange bogosity. */
54 d.exc = exception;
55 d.exc_code = code;
56 d.exc_subcode = subcode;
58 /* Call the machine-dependent function to translate the Mach exception
59 codes into a signal number and subcode. */
60 _hurd_exception2signal (&d, &signo);
62 return HURD_PREEMPT_SIGNAL_P (&_hurdsig_fault_preemptor, signo, d.code)
63 ? 0 : EGREGIOUS;
66 static void
67 faulted (void)
69 struct
71 mach_msg_header_t head;
72 char buf[64];
73 } request;
74 struct
76 mach_msg_header_t head;
77 mach_msg_type_t type;
78 int result;
79 } reply;
80 extern int _hurdsig_fault_exc_server (mach_msg_header_t *,
81 mach_msg_header_t *);
83 /* Wait for the exception_raise message forwarded by the proc server. */
85 if (__mach_msg (&request.head, MACH_RCV_MSG, 0,
86 sizeof request, forward_sigexc,
87 MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL)
88 != MACH_MSG_SUCCESS)
89 __libc_fatal ("msg receive failed on signal thread exc\n");
91 /* Run the exc demuxer which should call the server function above.
92 That function returns 0 if the exception was expected. */
93 _hurdsig_fault_exc_server (&request.head, &reply.head);
94 if (reply.head.msgh_remote_port != MACH_PORT_NULL)
95 __mach_msg (&reply.head, MACH_SEND_MSG, reply.head.msgh_size,
96 0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
97 if (reply.result == MIG_BAD_ID)
98 __mach_msg_destroy (&request.head);
100 if (reply.result)
101 __libc_fatal ("BUG: unexpected fault in signal thread\n");
103 _hurdsig_fault_preemptor.signals = 0;
104 longjmp (_hurdsig_fault_env, 1);
107 static char faultstack[1024];
109 /* Send exceptions for the signal thread to the proc server.
110 It will forward the message on to our message port,
111 and then restore the thread's state to code which
112 does `longjmp (_hurd_sigthread_fault_env, 1)'. */
114 void
115 _hurdsig_fault_init (void)
117 error_t err;
118 struct machine_thread_state state;
119 mach_port_t sigexc;
121 /* Allocate a port to receive signal thread exceptions.
122 We will move this receive right to the proc server. */
123 err = __mach_port_allocate (__mach_task_self (),
124 MACH_PORT_RIGHT_RECEIVE, &sigexc);
125 assert_perror (err);
126 err = __mach_port_allocate (__mach_task_self (),
127 MACH_PORT_RIGHT_RECEIVE, &forward_sigexc);
128 assert_perror (err);
130 /* Allocate a port to receive the exception msgs forwarded
131 from the proc server. */
132 err = __mach_port_insert_right (__mach_task_self (), sigexc,
133 sigexc, MACH_MSG_TYPE_MAKE_SEND);
134 assert_perror (err);
136 /* Set the queue limit for this port to just one. The proc server will
137 notice if we ever get a second exception while one remains queued and
138 unreceived, and decide we are hopelessly buggy. */
139 err = __mach_port_set_qlimit (__mach_task_self (), forward_sigexc, 1);
140 assert_perror (err);
142 /* This state will be restored when we fault.
143 It runs the function above. */
144 memset (&state, 0, sizeof state);
145 MACHINE_THREAD_STATE_SET_PC (&state, faulted);
146 MACHINE_THREAD_STATE_SET_SP (&state, faultstack, sizeof faultstack);
148 err = __USEPORT
149 (PROC,
150 __proc_handle_exceptions (port,
151 sigexc,
152 forward_sigexc, MACH_MSG_TYPE_MAKE_SEND,
153 MACHINE_THREAD_STATE_FLAVOR,
154 (natural_t *) &state,
155 MACHINE_THREAD_STATE_COUNT));
156 assert_perror (err);
158 /* Direct signal thread exceptions to the proc server. */
159 err = __thread_set_special_port (_hurd_msgport_thread,
160 THREAD_EXCEPTION_PORT, sigexc);
161 __mach_port_deallocate (__mach_task_self (), sigexc);
162 assert_perror (err);