1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
/* Handle faults in the signal thread.
Copyright (C) 1994-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <hurd.h>
#include <hurd/signal.h>
#include "hurdfault.h"
#include <errno.h>
#include <string.h>
#include <setjmp.h>
#include <stdio.h>
#include <thread_state.h>
#include "faultexc_server.h" /* mig-generated header for our exc server. */
#include <assert.h>
jmp_buf _hurdsig_fault_env;
struct hurd_signal_preemptor _hurdsig_fault_preemptor = {0};
/* XXX temporary to deal with spelling fix */
weak_alias (_hurdsig_fault_preemptor, _hurdsig_fault_preempter)
static mach_port_t forward_sigexc;
kern_return_t
_hurdsig_fault_catch_exception_raise (mach_port_t port,
thread_t thread,
task_t task,
#ifdef EXC_MASK_ALL /* New interface flavor. */
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t codeCnt
#else /* Vanilla Mach 3.0 interface. */
integer_t exception,
integer_t code, integer_t subcode
#endif
)
{
int signo;
struct hurd_signal_detail d;
if (port != forward_sigexc ||
thread != _hurd_msgport_thread || task != __mach_task_self ())
return EPERM; /* Strange bogosity. */
d.exc = exception;
#ifdef EXC_MASK_ALL
assert (codeCnt >= 2);
d.exc_code = code[0];
d.exc_subcode = code[1];
#else
d.exc_code = code;
d.exc_subcode = subcode;
#endif
/* Call the machine-dependent function to translate the Mach exception
codes into a signal number and subcode. */
_hurd_exception2signal (&d, &signo);
return HURD_PREEMPT_SIGNAL_P (&_hurdsig_fault_preemptor, signo, d.code)
? 0 : EGREGIOUS;
}
#ifdef EXC_MASK_ALL
/* XXX New interface flavor has additional RPCs that we could be using
instead. These RPCs roll a thread_get_state/thread_set_state into
the message, so the signal thread ought to use these to save some calls.
*/
kern_return_t
_hurdsig_fault_catch_exception_raise_state
(mach_port_t port,
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t codeCnt,
int *flavor,
thread_state_t old_state,
mach_msg_type_number_t old_stateCnt,
thread_state_t new_state,
mach_msg_type_number_t *new_stateCnt)
{
abort ();
return KERN_FAILURE;
}
kern_return_t
_hurdsig_fault_catch_exception_raise_state_identity
(mach_port_t exception_port,
thread_t thread,
task_t task,
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t codeCnt,
int *flavor,
thread_state_t old_state,
mach_msg_type_number_t old_stateCnt,
thread_state_t new_state,
mach_msg_type_number_t *new_stateCnt)
{
abort ();
return KERN_FAILURE;
}
#endif
#ifdef NDR_CHAR_ASCII /* OSF Mach flavors have different names. */
# define mig_reply_header_t mig_reply_error_t
#endif
static void
faulted (void)
{
struct
{
mach_msg_header_t head;
char buf[64];
} request;
mig_reply_header_t reply;
extern int _hurdsig_fault_exc_server (mach_msg_header_t *,
mach_msg_header_t *);
/* Wait for the exception_raise message forwarded by the proc server. */
if (__mach_msg (&request.head, MACH_RCV_MSG, 0,
sizeof request, forward_sigexc,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL)
!= MACH_MSG_SUCCESS)
__libc_fatal ("msg receive failed on signal thread exc\n");
/* Run the exc demuxer which should call the server function above.
That function returns 0 if the exception was expected. */
_hurdsig_fault_exc_server (&request.head, &reply.Head);
if (reply.Head.msgh_remote_port != MACH_PORT_NULL)
__mach_msg (&reply.Head, MACH_SEND_MSG, reply.Head.msgh_size,
0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (reply.RetCode == MIG_BAD_ID)
__mach_msg_destroy (&request.head);
if (reply.RetCode)
__libc_fatal ("BUG: unexpected fault in signal thread\n");
_hurdsig_fault_preemptor.signals = 0;
longjmp (_hurdsig_fault_env, 1);
}
static char faultstack[1024];
/* Send exceptions for the signal thread to the proc server.
It will forward the message on to our message port,
and then restore the thread's state to code which
does `longjmp (_hurd_sigthread_fault_env, 1)'. */
void
_hurdsig_fault_init (void)
{
error_t err;
struct machine_thread_state state;
mach_port_t sigexc;
/* Allocate a port to receive signal thread exceptions.
We will move this receive right to the proc server. */
err = __mach_port_allocate (__mach_task_self (),
MACH_PORT_RIGHT_RECEIVE, &sigexc);
assert_perror (err);
err = __mach_port_allocate (__mach_task_self (),
MACH_PORT_RIGHT_RECEIVE, &forward_sigexc);
assert_perror (err);
/* Allocate a port to receive the exception msgs forwarded
from the proc server. */
err = __mach_port_insert_right (__mach_task_self (), sigexc,
sigexc, MACH_MSG_TYPE_MAKE_SEND);
assert_perror (err);
/* Set the queue limit for this port to just one. The proc server will
notice if we ever get a second exception while one remains queued and
unreceived, and decide we are hopelessly buggy. */
#ifdef MACH_PORT_RECEIVE_STATUS_COUNT
{
const mach_port_limits_t lim = { mpl_qlimit: 1 };
assert (MACH_PORT_RECEIVE_STATUS_COUNT == sizeof lim / sizeof (natural_t));
err = __mach_port_set_attributes (__mach_task_self (), forward_sigexc,
MACH_PORT_RECEIVE_STATUS,
(mach_port_info_t) &lim,
MACH_PORT_RECEIVE_STATUS_COUNT);
}
#else
err = __mach_port_set_qlimit (__mach_task_self (), forward_sigexc, 1);
#endif
assert_perror (err);
/* This state will be restored when we fault.
It runs the function above. */
memset (&state, 0, sizeof state);
MACHINE_THREAD_STATE_SET_PC (&state, faulted);
MACHINE_THREAD_STATE_SET_SP (&state, faultstack, sizeof faultstack);
err = __USEPORT
(PROC,
__proc_handle_exceptions (port,
sigexc,
forward_sigexc, MACH_MSG_TYPE_MAKE_SEND,
MACHINE_THREAD_STATE_FLAVOR,
(natural_t *) &state,
MACHINE_THREAD_STATE_COUNT));
assert_perror (err);
/* Direct signal thread exceptions to the proc server. */
#ifdef THREAD_EXCEPTION_PORT
err = __thread_set_special_port (_hurd_msgport_thread,
THREAD_EXCEPTION_PORT, sigexc);
#elif defined (EXC_MASK_ALL)
__thread_set_exception_ports (_hurd_msgport_thread,
EXC_MASK_ALL & ~(EXC_MASK_SYSCALL
| EXC_MASK_MACH_SYSCALL
| EXC_MASK_RPC_ALERT),
sigexc,
EXCEPTION_STATE_IDENTITY,
MACHINE_THREAD_STATE);
#else
# error thread_set_exception_ports?
#endif
__mach_port_deallocate (__mach_task_self (), sigexc);
assert_perror (err);
}
|
