1 | /* Copyright (C) 1994-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <mach/exc_server.h> |
19 | #include <hurd/signal.h> |
20 | #include <assert.h> |
21 | |
22 | /* Called by the microkernel when a thread gets an exception. */ |
23 | |
24 | kern_return_t |
25 | _S_catch_exception_raise (mach_port_t port, |
26 | thread_t thread, |
27 | task_t task, |
28 | #ifdef EXC_MASK_ALL /* New interface flavor. */ |
29 | exception_type_t exception, |
30 | exception_data_t code, |
31 | mach_msg_type_number_t codeCnt |
32 | #else /* Vanilla Mach 3.0 interface. */ |
33 | integer_t exception, |
34 | integer_t code, integer_t subcode |
35 | #endif |
36 | ) |
37 | { |
38 | struct hurd_sigstate *ss; |
39 | int signo; |
40 | struct hurd_signal_detail d; |
41 | |
42 | if (task != __mach_task_self ()) |
43 | /* The sender wasn't the kernel. */ |
44 | return EPERM; |
45 | |
46 | d.exc = exception; |
47 | #ifdef EXC_MASK_ALL |
48 | assert (codeCnt >= 2); |
49 | d.exc_code = code[0]; |
50 | d.exc_subcode = code[1]; |
51 | #else |
52 | d.exc_code = code; |
53 | d.exc_subcode = subcode; |
54 | #endif |
55 | |
56 | /* Call the machine-dependent function to translate the Mach exception |
57 | codes into a signal number and subcode. */ |
58 | _hurd_exception2signal (detail: &d, signo: &signo); |
59 | |
60 | /* Find the sigstate structure for the faulting thread. */ |
61 | __mutex_lock (&_hurd_siglock); |
62 | for (ss = _hurd_sigstates; ss != NULL; ss = ss->next) |
63 | if (ss->thread == thread) |
64 | break; |
65 | __mutex_unlock (&_hurd_siglock); |
66 | if (ss == NULL) |
67 | ss = _hurd_thread_sigstate (thread); /* Allocate a fresh one. */ |
68 | |
69 | if (__spin_lock_locked (&ss->lock)) |
70 | { |
71 | /* Loser. The thread faulted with its sigstate lock held. Its |
72 | sigstate data is now suspect. So we reset the parts of it which |
73 | could cause trouble for the signal thread. Anything else |
74 | clobbered therein will just hose this user thread, but it's |
75 | faulting already. |
76 | |
77 | This is almost certainly a library bug: unless random memory |
78 | clobberation caused the sigstate lock to gratuitously appear held, |
79 | no code should do anything that can fault while holding the |
80 | sigstate lock. */ |
81 | |
82 | __spin_unlock (&ss->critical_section_lock); |
83 | ss->context = NULL; |
84 | __spin_unlock (&ss->lock); |
85 | } |
86 | |
87 | /* Post the signal. */ |
88 | _hurd_internal_post_signal (ss, signo, &d, |
89 | MACH_PORT_NULL, MACH_MSG_TYPE_PORT_SEND, |
90 | 0); |
91 | |
92 | return KERN_SUCCESS; |
93 | } |
94 | |
95 | #ifdef EXC_MASK_ALL |
96 | /* XXX New interface flavor has additional RPCs that we could be using |
97 | instead. These RPCs roll a thread_get_state/thread_set_state into |
98 | the message, so the signal thread ought to use these to save some calls. |
99 | */ |
100 | kern_return_t |
101 | _S_catch_exception_raise_state (mach_port_t port, |
102 | exception_type_t exception, |
103 | exception_data_t code, |
104 | mach_msg_type_number_t codeCnt, |
105 | int *flavor, |
106 | thread_state_t old_state, |
107 | mach_msg_type_number_t old_stateCnt, |
108 | thread_state_t new_state, |
109 | mach_msg_type_number_t *new_stateCnt) |
110 | { |
111 | abort (); |
112 | return KERN_FAILURE; |
113 | } |
114 | |
115 | kern_return_t |
116 | _S_catch_exception_raise_state_identity (mach_port_t exception_port, |
117 | thread_t thread, |
118 | task_t task, |
119 | exception_type_t exception, |
120 | exception_data_t code, |
121 | mach_msg_type_number_t codeCnt, |
122 | int *flavor, |
123 | thread_state_t old_state, |
124 | mach_msg_type_number_t old_stateCnt, |
125 | thread_state_t new_state, |
126 | mach_msg_type_number_t *new_stateCnt) |
127 | { |
128 | abort (); |
129 | return KERN_FAILURE; |
130 | } |
131 | #endif |
132 | |