1 | /* Report on what a thread in our task is waiting for. |
2 | Copyright (C) 1996-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
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. |
9 | |
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. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <hurd.h> |
20 | #include <hurd/signal.h> |
21 | #include <hurd/fd.h> |
22 | #include <string.h> |
23 | #include <assert.h> |
24 | #include <hurd/msg_server.h> |
25 | #include <thread_state.h> |
26 | #include <intr-msg.h> |
27 | |
28 | static char * |
29 | describe_number (char *description, const char *flavor, long int i, size_t size) |
30 | { |
31 | unsigned long int j; |
32 | char *limit = description + size; |
33 | char *p = flavor == NULL ? description : __stpncpy (dest: description, src: flavor, n: size); |
34 | char *end; |
35 | |
36 | if (p == limit) |
37 | return p; |
38 | |
39 | /* Handle sign. */ |
40 | if (i < 0) |
41 | { |
42 | i = -i; |
43 | *p++ = '-'; |
44 | } |
45 | |
46 | if (p == limit) |
47 | return p; |
48 | |
49 | /* Allocate space for the number at the end of DESCRIPTION. */ |
50 | for (j = i; j >= 10; j /= 10) |
51 | p++; |
52 | end = p + 1; |
53 | |
54 | if (end < limit) |
55 | *end = '\0'; |
56 | else |
57 | end = limit; |
58 | |
59 | do |
60 | { |
61 | if (p < limit) |
62 | *p = '0' + i % 10; |
63 | p--; |
64 | i /= 10; |
65 | } while (i != 0); |
66 | |
67 | return end; |
68 | } |
69 | |
70 | static char * |
71 | describe_port (char *description, mach_port_t port, size_t size) |
72 | { |
73 | int i; |
74 | |
75 | if (port == MACH_PORT_NULL) |
76 | return __stpncpy (dest: description, src: "(null)" , n: size); |
77 | if (port == MACH_PORT_DEAD) |
78 | return __stpncpy (dest: description, src: "(dead)" , n: size); |
79 | |
80 | if (port == __mach_task_self ()) |
81 | return __stpncpy (dest: description, src: "task-self" , n: size); |
82 | |
83 | for (i = 0; i < _hurd_nports; ++i) |
84 | if (port == _hurd_ports[i].port) |
85 | return describe_number (description, flavor: "init#" , i, size); |
86 | |
87 | if (_hurd_init_dtable) |
88 | { |
89 | for (i = 0; i < _hurd_init_dtablesize; ++i) |
90 | if (port == _hurd_init_dtable[i]) |
91 | return describe_number (description, flavor: "fd#" , i, size); |
92 | } |
93 | if (_hurd_dtable) |
94 | { |
95 | for (i = 0; i < _hurd_dtablesize; ++i) |
96 | if (_hurd_dtable[i] == NULL) |
97 | continue; |
98 | else if (port == _hurd_dtable[i]->port.port) |
99 | return describe_number (description, flavor: "fd#" , i, size); |
100 | else if (port == _hurd_dtable[i]->ctty.port) |
101 | return describe_number (description, flavor: "bgfd#" , i, size); |
102 | } |
103 | |
104 | return describe_number (description, flavor: "port#" , i: port, size); |
105 | } |
106 | |
107 | |
108 | /* We want _HURD_ITIMER_THREAD, but don't want to link in the itimer code |
109 | unnecessarily. */ |
110 | extern thread_t _hurd_itimer_thread; /* XXX */ |
111 | weak_extern (_hurd_itimer_thread) |
112 | |
113 | kern_return_t |
114 | _S_msg_report_wait (mach_port_t msgport, thread_t thread, |
115 | string_t description, mach_msg_id_t *msgid) |
116 | { |
117 | char *limit = description + 1024; /* XXX */ |
118 | char *cur = description; |
119 | *msgid = 0; |
120 | |
121 | if (thread == _hurd_msgport_thread) |
122 | /* Cute. */ |
123 | cur = __stpncpy (dest: cur, src: "msgport" , n: limit - cur); |
124 | else if (&_hurd_itimer_thread && thread == _hurd_itimer_thread) |
125 | cur = __stpncpy (dest: cur, src: "itimer" , n: limit - cur); |
126 | else |
127 | { |
128 | /* Make sure this is really one of our threads. */ |
129 | |
130 | struct hurd_sigstate *ss; |
131 | |
132 | __mutex_lock (&_hurd_siglock); |
133 | for (ss = _hurd_sigstates; ss != NULL; ss = ss->next) |
134 | if (ss->thread == thread) |
135 | break; |
136 | __mutex_unlock (&_hurd_siglock); |
137 | if (ss == NULL) |
138 | /* To hell with you. */ |
139 | return EINVAL; |
140 | |
141 | if (ss->suspended != MACH_PORT_NULL) |
142 | cur = __stpncpy (dest: cur, src: "sigsuspend" , n: limit - cur); |
143 | else |
144 | { |
145 | /* Examine the thread's state to see if it is blocked in an RPC. */ |
146 | |
147 | struct machine_thread_state state; |
148 | mach_msg_type_number_t count = MACHINE_THREAD_STATE_COUNT; |
149 | error_t err; |
150 | |
151 | err = __thread_get_state (thread, MACHINE_THREAD_STATE_FLAVOR, |
152 | (natural_t *) &state, &count); |
153 | if (err) |
154 | return err; |
155 | assert (count == MACHINE_THREAD_STATE_COUNT); |
156 | if (SYSCALL_EXAMINE (&state, msgid)) |
157 | { |
158 | mach_port_t send_port, rcv_port; |
159 | mach_msg_option_t option; |
160 | mach_msg_timeout_t timeout; |
161 | |
162 | /* Blocked in a system call. */ |
163 | if (*msgid == -25 |
164 | /* mach_msg system call. Examine its parameters. */ |
165 | && MSG_EXAMINE (&state, msgid, &rcv_port, &send_port, |
166 | &option, &timeout) == 0) |
167 | { |
168 | if (send_port != MACH_PORT_NULL && *msgid != 0) |
169 | { |
170 | /* For the normal case of RPCs, we consider the |
171 | destination port to be the interesting thing |
172 | whether we are in fact sending or receiving at the |
173 | moment. That tells us who we are waiting for the |
174 | reply from. */ |
175 | if (send_port == ss->intr_port) |
176 | { |
177 | /* This is a Hurd interruptible RPC. |
178 | Mark it by surrounding the port description |
179 | string with [...] brackets. */ |
180 | if (cur < limit) |
181 | *cur++ = '['; |
182 | cur = describe_port (cur, send_port, limit - cur); |
183 | if (cur < limit) |
184 | *cur++ = ']'; |
185 | } |
186 | else |
187 | cur = describe_port (cur, send_port, limit - cur); |
188 | } |
189 | else if (rcv_port != MACH_PORT_NULL) |
190 | { |
191 | /* This system call had no send port, but had a |
192 | receive port. The msgid we extracted is then just |
193 | some garbage or perhaps the msgid of the last |
194 | message this thread received, but it's not a |
195 | helpful thing to return. */ |
196 | cur = describe_port (cur, rcv_port, limit - cur); |
197 | cur = __stpncpy (dest: cur, src: ":rcv" , n: limit - cur); |
198 | *msgid = 0; |
199 | } |
200 | else if ((option & (MACH_RCV_MSG|MACH_RCV_TIMEOUT)) |
201 | == (MACH_RCV_MSG|MACH_RCV_TIMEOUT)) |
202 | { |
203 | /* A receive with no valid port can be used for a |
204 | pure timeout. Report the timeout value (counted |
205 | in milliseconds); note this is the original total |
206 | time, not the time remaining. */ |
207 | cur = describe_number (cur, 0, timeout, limit - cur); |
208 | cur = __stpncpy (dest: cur, src: "ms" , n: limit - cur); |
209 | *msgid = 0; |
210 | } |
211 | else |
212 | { |
213 | cur = __stpncpy (dest: cur, src: "mach_msg" , n: limit - cur); |
214 | *msgid = 0; |
215 | } |
216 | } |
217 | else /* Some other system call. */ |
218 | { |
219 | cur = describe_number (description: cur, flavor: "syscall#" , i: *msgid, size: limit - cur); |
220 | *msgid = 0; |
221 | } |
222 | } |
223 | } |
224 | } |
225 | |
226 | __mach_port_deallocate (__mach_task_self (), thread); |
227 | |
228 | if (cur == limit) |
229 | return ENOMEM; |
230 | |
231 | *cur = '\0'; |
232 | return 0; |
233 | } |
234 | |
235 | kern_return_t |
236 | _S_msg_describe_ports (mach_port_t msgport, mach_port_t refport, |
237 | const mach_port_t *ports, mach_msg_type_number_t nports, |
238 | char **desc, mach_msg_type_number_t *desclen) |
239 | { |
240 | char *p, *end; |
241 | |
242 | if (__USEPORT (AUTH, msgport != port)) |
243 | return EPERM; |
244 | |
245 | end = *desc + *desclen; |
246 | p = *desc; |
247 | while (nports-- > 0) |
248 | { |
249 | char this[200]; |
250 | describe_port (this, *ports++, sizeof this); |
251 | p = __stpncpy (dest: p, src: this, n: end - p); |
252 | if (p == end && p[-1] != '\0') |
253 | return ENOMEM; |
254 | } |
255 | |
256 | *desclen = p - *desc; |
257 | return 0; |
258 | } |
259 | |