1 /*
2 * Copyright (c) 2014,2019 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include "namespace.h"
36 #include <sys/cdefs.h>
37 #include <sys/types.h>
38 #include <sys/syscall.h>
39 #include <sys/upmap.h>
40 #include <sys/time.h>
41 #include <sys/mman.h>
42 #include <sys/fcntl.h>
43 #include <errno.h>
44 #include <stdio.h>
45 #include <unistd.h>
46 #include <time.h>
47 #include <pthread.h>
48 #include "un-namespace.h"
49 #include "libc_private.h"
50 #include "upmap.h"
51
52 /*
53 * kpmap - Global user/kernel shared map (RO)
54 * upmap - Per-process user/kernel shared map (RW)
55 * lpmap - Per-thread user/kernel shared map (RW)
56 */
57 static pthread_mutex_t ukpmap_lock;
58 static ukpheader_t *__kpmap_headers;
59 static ukpheader_t *__upmap_headers;
60 __thread ukpheader_t *__lpmap_headers TLS_ATTRIBUTE;
61 __thread uint32_t *__lpmap_blockallsigs TLS_ATTRIBUTE;
62
63 static __thread int lpmap_ok;
64 static int kpmap_ok;
65 static int upmap_ok;
66 static pthread_once_t upmap_once = PTHREAD_ONCE_INIT;
67
68
69 /*
70 * Map the requested data item from the user-kernel global shared mmap
71 *
72 * *state is set to -1 on failure, else it is left alone.
73 * *datap is set to a pointer to the item on success, else it is left alone.
74 * If type == 0 this function finalizes state, setting it to 1 if it is 0.
75 */
76 void
__kpmap_map(void * datap,int * state,uint16_t type)77 __kpmap_map(void *datap, int *state, uint16_t type)
78 {
79 ukpheader_t *head;
80
81 if (__isthreaded)
82 _pthread_mutex_lock(&ukpmap_lock);
83
84 if (kpmap_ok <= 0) {
85 int fd;
86
87 if (kpmap_ok < 0)
88 goto failed;
89 fd = _open("/dev/kpmap", O_RDONLY);
90 if (fd < 0) {
91 kpmap_ok = -1;
92 goto failed;
93 }
94 __kpmap_headers = mmap(NULL, KPMAP_MAPSIZE,
95 PROT_READ, MAP_SHARED | MAP_FILE,
96 fd, 0);
97 _close(fd);
98 if ((void *)__kpmap_headers == MAP_FAILED) {
99 kpmap_ok = -1;
100 goto failed;
101 }
102 kpmap_ok = 1;
103 }
104
105 /*
106 * Special case to finalize state
107 */
108 if (type == 0) {
109 if (*state == 0)
110 *state = 1;
111 if (__isthreaded)
112 _pthread_mutex_unlock(&ukpmap_lock);
113 return;
114 }
115
116 /*
117 * Look for type.
118 */
119 for (head = __kpmap_headers; head->type; ++head) {
120 if (head->type == type) {
121 *(void **)datap = (char *)__kpmap_headers +
122 head->offset;
123 if (__isthreaded)
124 _pthread_mutex_unlock(&ukpmap_lock);
125 return;
126 }
127 }
128 failed:
129 *state = -1;
130 if (__isthreaded)
131 _pthread_mutex_unlock(&ukpmap_lock);
132 }
133
134 /*
135 * Map the requested data item from the user-kernel per-process shared mmap
136 *
137 * *state is set to -1 on failure, else it is left alone.
138 * *datap is set to a pointer to the item on success, else it is left alone.
139 * If type == 0 this function finalizes state, setting it to 1 if it is 0.
140 */
141 void
__upmap_map(void * datap,int * state,uint16_t type)142 __upmap_map(void *datap, int *state, uint16_t type)
143 {
144 ukpheader_t *head;
145
146 if (__isthreaded)
147 _pthread_mutex_lock(&ukpmap_lock);
148
149 if (upmap_ok <= 0) {
150 int fd;
151
152 if (upmap_ok < 0)
153 goto failed;
154 fd = _open("/dev/upmap", O_RDWR);
155 if (fd < 0) {
156 upmap_ok = -1;
157 goto failed;
158 }
159 __upmap_headers = mmap(NULL, UPMAP_MAPSIZE,
160 PROT_READ | PROT_WRITE,
161 MAP_SHARED | MAP_FILE,
162 fd, 0);
163 _close(fd);
164 if ((void *)__upmap_headers == MAP_FAILED) {
165 upmap_ok = -1;
166 goto failed;
167 }
168 upmap_ok = 1;
169 }
170
171 /*
172 * Special case to finalize state
173 */
174 if (type == 0) {
175 if (*state == 0)
176 *state = 1;
177 if (__isthreaded)
178 _pthread_mutex_unlock(&ukpmap_lock);
179 return;
180 }
181
182 /*
183 * Look for type.
184 */
185 for (head = __upmap_headers; head->type; ++head) {
186 if (head->type == type) {
187 *(void **)datap = (char *)__upmap_headers +
188 head->offset;
189 if (__isthreaded)
190 _pthread_mutex_unlock(&ukpmap_lock);
191 return;
192 }
193 }
194 failed:
195 *state = -1;
196 if (__isthreaded)
197 _pthread_mutex_unlock(&ukpmap_lock);
198 }
199
200 /*
201 * Map the requested data item from the user-kernel per-thread shared mmap
202 *
203 * *state is set to -1 on failure, else it is left alone.
204 * *datap is set to a pointer to the item on success, else it is left alone.
205 * If type == 0 this function finalizes state, setting it to 1 if it is 0.
206 *
207 * WARNING! This code is used all over pthreads and must NOT make any
208 * reentrant pthreads calls until after the mapping has been
209 * set up.
210 */
211 static pthread_key_t lpmap_key;
212
213 static void lpmap_unmap(void **datap);
214
215 void
__lpmap_map(void * datap,int * state,uint16_t type)216 __lpmap_map(void *datap, int *state, uint16_t type)
217 {
218 ukpheader_t *head;
219
220 if (lpmap_ok <= 0) {
221 int fd;
222
223 if (lpmap_ok < 0)
224 goto failed;
225 fd = _open("/dev/lpmap", O_RDWR);
226 if (fd < 0) {
227 lpmap_ok = -1;
228 goto failed;
229 }
230 __lpmap_headers = mmap(NULL, LPMAP_MAPSIZE,
231 PROT_READ | PROT_WRITE,
232 MAP_SHARED | MAP_FILE,
233 fd, 0);
234 _close(fd);
235 if ((void *)__lpmap_headers == MAP_FAILED) {
236 lpmap_ok = -1;
237 goto failed;
238 }
239 lpmap_ok = 1;
240 _pthread_setspecific(lpmap_key, &__lpmap_headers);
241 }
242
243 /*
244 * Special case to finalize state
245 */
246 if (type == 0) {
247 if (*state == 0)
248 *state = 1;
249 return;
250 }
251
252 /*
253 * Look for type.
254 */
255 for (head = __lpmap_headers; head->type; ++head) {
256 if (head->type == type) {
257 *(void **)datap = (char *)__lpmap_headers +
258 head->offset;
259 return;
260 }
261 }
262 failed:
263 *state = -1;
264 }
265
266 /*
267 * Cleanup thread state
268 */
269 static void
lpmap_unmap(void ** datap)270 lpmap_unmap(void **datap)
271 {
272 ukpheader_t *lpmap = *datap;
273
274 lpmap_ok = -1;
275 if (lpmap) {
276 __lpmap_blockallsigs = NULL;
277 *datap = NULL;
278 munmap(lpmap, LPMAP_MAPSIZE);
279 }
280 }
281
282 /*
283 * upmap initialization code, _upmap_thr_init() is called for the initial
284 * main thread by libc or pthreads, and on every thread create. We need
285 * the __lpmap_blockallsigs pointer ASAP because it is used everywhere in
286 * pthreads.
287 *
288 * If pthreads is not linked in, _pthread_once() still runs via a stub in
289 * libc, and _pthread_key_create() is a NOP.
290 *
291 * NOTE: These pthreads calls are stubs when pthreads is not linked in.
292 * The once routine will still be run once regardless.
293 */
294 static
295 void
_upmap_init_once(void)296 _upmap_init_once(void)
297 {
298 /* ignore error from stub if not threaded */
299 _pthread_key_create(&lpmap_key, (void (*)(void *))lpmap_unmap);
300 }
301
302 void
_upmap_thr_init(void)303 _upmap_thr_init(void)
304 {
305 int dummy_state = 0;
306
307 _pthread_once(&upmap_once, _upmap_init_once);
308 __lpmap_map(&__lpmap_blockallsigs, &dummy_state, LPTYPE_BLOCKALLSIGS);
309 }
310