1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <ctype.h>
30 #include <dirent.h>
31 #include <errno.h>
32 #include <fcntl.h>
33 #include <limits.h>
34 #include <pthread.h>
35 #include <stdio.h> // For FOPEN_MAX.
36 #include <string.h>
37 #include <sys/sysconf.h>
38 #include <time.h>
39 #include <unistd.h>
40
41 #include "private/bionic_tls.h"
42 #include "private/ScopedReaddir.h"
43
44 /* seems to be the default on Linux, per the GLibc sources and my own digging */
45
46 #define SYSTEM_CLK_TCK 100
47 #define SYSTEM_IOV_MAX 1024
48 #define SYSTEM_DELAYTIMER_MAX 2147483647
49 #define SYSTEM_MQ_OPEN_MAX 8
50 #define SYSTEM_MQ_PRIO_MAX 32768
51 #define SYSTEM_SEM_NSEMS_MAX 256
52 #define SYSTEM_SEM_VALUE_MAX 0x3fffffff /* see bionic/semaphore.c */
53 #define SYSTEM_SIGQUEUE_MAX 32
54 #define SYSTEM_TIMER_MAX 32
55 #define SYSTEM_LOGIN_NAME_MAX 256
56 #define SYSTEM_TTY_NAME_MAX 32
57
58 /* the following depends on our implementation */
59 #define SYSTEM_ATEXIT_MAX 65536 /* our implementation is unlimited */
60 #define SYSTEM_THREAD_THREADS_MAX 2048 /* really unlimited */
61
62 #define SYSTEM_2_C_BIND _POSIX_VERSION /* Posix C binding version */
63 #define SYSTEM_2_C_VER _POSIX2_C_VERSION
64 #define SYSTEM_2_C_DEV -1 /* Posix C development tools unsupported on the device */
65 #define SYSTEM_2_FORT_DEV -1 /* Fortran development unsupported */
66 #define SYSTEM_2_FORT_RUN -1 /* Fortran runtime unsupported */
67 #define SYSTEM_2_SW_DEV -1 /* posix software dev utilities unsupported */
68 #define SYSTEM_2_LOCALEDEF -1 /* localedef() unimplemented */
69 #define SYSTEM_2_UPE -1 /* No UPE for you ! (User Portability Utilities) */
70 #define SYSTEM_2_VERSION -1 /* No posix command-line tools */
71
__matches_cpuN(const char * s)72 static bool __matches_cpuN(const char* s) {
73 // The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
74 unsigned cpu;
75 char dummy;
76 return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
77 }
78
__sysconf_nprocessors_conf()79 static int __sysconf_nprocessors_conf() {
80 // On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
81 // from there. This method works on both.
82 ScopedReaddir reader("/sys/devices/system/cpu");
83 if (reader.IsBad()) {
84 return 1;
85 }
86
87 int result = 0;
88 dirent* entry;
89 while ((entry = reader.ReadEntry()) != NULL) {
90 if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
91 ++result;
92 }
93 }
94 return result;
95 }
96
__sysconf_nprocessors_onln()97 static int __sysconf_nprocessors_onln() {
98 FILE* fp = fopen("/proc/stat", "r");
99 if (fp == NULL) {
100 return 1;
101 }
102
103 int result = 0;
104 char buf[256];
105 while (fgets(buf, sizeof(buf), fp) != NULL) {
106 // Extract just the first word from the line.
107 // 'cpu0 7976751 1364388 3116842 469770388 8629405 0 49047 0 0 0'
108 char* p = strchr(buf, ' ');
109 if (p != NULL) {
110 *p = 0;
111 }
112 if (__matches_cpuN(buf)) {
113 ++result;
114 }
115 }
116 fclose(fp);
117 return result;
118 }
119
__get_meminfo(const char * pattern)120 static int __get_meminfo(const char* pattern) {
121 FILE* fp = fopen("/proc/meminfo", "r");
122 if (fp == NULL) {
123 return -1;
124 }
125
126 int result = -1;
127 char buf[256];
128 while (fgets(buf, sizeof(buf), fp) != NULL) {
129 long total;
130 if (sscanf(buf, pattern, &total) == 1) {
131 result = (int) (total / (PAGE_SIZE/1024));
132 break;
133 }
134 }
135 fclose(fp);
136 return result;
137 }
138
__sysconf_phys_pages()139 static int __sysconf_phys_pages() {
140 return __get_meminfo("MemTotal: %ld kB");
141 }
142
__sysconf_avphys_pages()143 static int __sysconf_avphys_pages() {
144 return __get_meminfo("MemFree: %ld kB");
145 }
146
__sysconf_monotonic_clock()147 static int __sysconf_monotonic_clock() {
148 timespec t;
149 int rc = clock_getres(CLOCK_MONOTONIC, &t);
150 return (rc == -1) ? -1 : _POSIX_VERSION;
151 }
152
sysconf(int name)153 long sysconf(int name) {
154 switch (name) {
155 #ifdef _POSIX_ARG_MAX
156 case _SC_ARG_MAX: return _POSIX_ARG_MAX;
157 #endif
158 #ifdef _POSIX2_BC_BASE_MAX
159 case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX;
160 #endif
161 #ifdef _POSIX2_BC_DIM_MAX
162 case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX;
163 #endif
164 #ifdef _POSIX2_BC_SCALE_MAX
165 case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX;
166 #endif
167 #ifdef _POSIX2_BC_STRING_MAX
168 case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX;
169 #endif
170 case _SC_CHILD_MAX: return CHILD_MAX;
171 case _SC_CLK_TCK: return SYSTEM_CLK_TCK;
172 #ifdef _POSIX2_COLL_WEIGHTS_MASK
173 case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MASK;
174 #endif
175 #ifdef _POSIX2_EXPR_NEST_MAX
176 case _SC_EXPR_NEST_MAX: return _POSIX2_EXPR_NEST_MAX;
177 #endif
178 #ifdef _POSIX2_LINE_MAX
179 case _SC_LINE_MAX: return _POSIX2_LINE_MAX;
180 #endif
181 case _SC_NGROUPS_MAX: return NGROUPS_MAX;
182 case _SC_OPEN_MAX: return OPEN_MAX;
183 //case _SC_PASS_MAX: return PASS_MAX;
184 case _SC_2_C_BIND: return SYSTEM_2_C_BIND;
185 case _SC_2_C_DEV: return SYSTEM_2_C_DEV;
186 case _SC_2_C_VERSION: return SYSTEM_2_C_VER;
187 //case _SC_2_CHAR_TERM: return ;
188 case _SC_2_FORT_DEV: return SYSTEM_2_FORT_DEV;
189 case _SC_2_FORT_RUN: return SYSTEM_2_FORT_RUN;
190 case _SC_2_LOCALEDEF: return SYSTEM_2_LOCALEDEF;
191 case _SC_2_SW_DEV: return SYSTEM_2_SW_DEV;
192 case _SC_2_UPE: return SYSTEM_2_UPE;
193 case _SC_2_VERSION: return SYSTEM_2_VERSION;
194 #ifdef _POSIX_JOB_CONTROL
195 case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL;
196 #endif
197 #ifdef _POSIX_SAVED_IDS
198 case _SC_SAVED_IDS: return _POSIX_SAVED_IDS;
199 #endif
200 #ifdef _POSIX_VERSION
201 case _SC_VERSION: return _POSIX_VERSION;
202 #endif
203 //case _SC_RE_DUP_<AX: return ;
204 case _SC_STREAM_MAX: return FOPEN_MAX;
205 //case _SC_TZNAME_MAX: return ;
206 #if _XOPEN_CRYPT
207 case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT;
208 #endif
209 #ifdef _XOPEN_ENH_I18N
210 case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N;
211 #endif
212 #ifdef _XOPEN_SHM
213 case _SC_XOPEN_SHM: return _XOPEN_SHM;
214 #endif
215 #ifdef _XOPEN_VERSION
216 case _SC_XOPEN_VERSION: return _XOPEN_VERSION;
217 #endif
218 #ifdef _XOPEN_XCU_VERSION
219 case _SC_XOPEN_XCU_VERSION: return _XOPEN_XCU_VERSION;
220 #endif
221 #ifdef _XOPEN_REALTIME
222 case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME;
223 #endif
224 #ifdef _XOPEN_REALTIME_THREADS
225 case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
226 #endif
227 #ifdef _XOPEN_LEGACY
228 case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY;
229 #endif
230 case _SC_ATEXIT_MAX: return SYSTEM_ATEXIT_MAX;
231 case _SC_IOV_MAX: return SYSTEM_IOV_MAX;
232
233 case _SC_PAGESIZE:
234 case _SC_PAGE_SIZE:
235 return PAGE_SIZE;
236
237 #ifdef _XOPEN_UNIX
238 case _SC_XOPEN_UNIX: return _XOPEN_UNIX;
239 #endif
240
241 // XXX: TODO: XBS5 nonsense
242
243 #ifdef AIO_LISTIO_MAX
244 case _SC_AIO_LISTIO_MAX: return AIO_LISTIO_MAX;
245 #endif
246 #ifdef AIO_MAX
247 case _SC_AIO_MAX: return AIO_MAX;
248 #endif
249 #ifdef AIO_PRIO_DELTA_MAX
250 case _SC_AIO_PRIO_DELTA_MAX: return AIO_PRIO_DELTA_MAX;
251 #endif
252 case _SC_DELAYTIMER_MAX: return SYSTEM_DELAYTIMER_MAX;
253 case _SC_MQ_OPEN_MAX: return SYSTEM_MQ_OPEN_MAX;
254 case _SC_MQ_PRIO_MAX: return SYSTEM_MQ_PRIO_MAX;
255 case _SC_RTSIG_MAX: return RTSIG_MAX;
256 case _SC_SEM_NSEMS_MAX: return SYSTEM_SEM_NSEMS_MAX;
257 case _SC_SEM_VALUE_MAX: return SYSTEM_SEM_VALUE_MAX;
258 case _SC_SIGQUEUE_MAX: return SYSTEM_SIGQUEUE_MAX;
259 case _SC_TIMER_MAX: return SYSTEM_TIMER_MAX;
260 #ifdef _POSIX_ASYNCHRONOUS_IO
261 case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO;
262 #endif
263 #ifdef _POSIX_FSYNC
264 case _SC_FSYNC: return _POSIX_FSYNC;
265 #endif
266 #ifdef _POSIX_MAPPED_FILES
267 case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES;
268 #endif
269 #ifdef _POSIX_MEMLOCK
270 case _SC_MEMLOCK: return _POSIX_MEMLOCK;
271 #endif
272 #ifdef _POSIX_MEMLOCK_RANGE
273 case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE
274 #endif
275 #ifdef _POSIX_MEMORY_PROTECTION
276 case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
277 #endif
278 #ifdef _POSIX_MESSAGE_PASSING
279 case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING;
280 #endif
281 #ifdef _POSIX_PRIORITIZED_IO
282 case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO;
283 #endif
284 #ifdef _POSIX_PRIORITY_SCHEDULING
285 case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING;
286 #endif
287 #ifdef _POSIX_REALTIME_SIGNALS
288 case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS;
289 #endif
290 #ifdef _POSIX_SEMAPHORES
291 case _SC_SEMAPHORES: return _POSIX_SEMAPHORES;
292 #endif
293 #ifdef _POSIX_SHARED_MEMORY_OBJECTS
294 case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS;
295 #endif
296 #ifdef _POSIX_SYNCHRONIZED_IO
297 case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO;
298 #endif
299 #ifdef _POSIX_TIMERS
300 case _SC_TIMERS: return _POSIX_TIMERS;
301 #endif
302
303 case _SC_GETGR_R_SIZE_MAX: return 1024;
304 case _SC_GETPW_R_SIZE_MAX: return 1024;
305
306 case _SC_LOGIN_NAME_MAX: return SYSTEM_LOGIN_NAME_MAX;
307
308 case _SC_THREAD_DESTRUCTOR_ITERATIONS:
309 return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
310
311 case _SC_THREAD_KEYS_MAX:
312 return (BIONIC_TLS_SLOTS - TLS_SLOT_FIRST_USER_SLOT - BIONIC_TLS_RESERVED_SLOTS);
313
314 case _SC_THREAD_STACK_MIN: return PTHREAD_STACK_MIN;
315 case _SC_THREAD_THREADS_MAX: return SYSTEM_THREAD_THREADS_MAX;
316 case _SC_TTY_NAME_MAX: return SYSTEM_TTY_NAME_MAX;
317 #ifdef _POSIX_THREADS
318 case _SC_THREADS: return _POSIX_THREADS;
319 #endif
320
321 case _SC_THREAD_ATTR_STACKADDR: return -1; // Removed in POSIX 2008
322 case _SC_THREAD_ATTR_STACKSIZE: return -1; // Removed in POSIX 2008
323
324 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
325 case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING;
326 #endif
327 #ifdef _POSIX_THREAD_PRIO_INHERIT
328 case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT;
329 #endif
330 #ifdef _POSIX_THREAD_PRIO_PROTECT
331 case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
332 #endif
333 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
334 case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS
335 #endif
336
337 case _SC_MONOTONIC_CLOCK: return __sysconf_monotonic_clock();
338 case _SC_NPROCESSORS_CONF: return __sysconf_nprocessors_conf();
339 case _SC_NPROCESSORS_ONLN: return __sysconf_nprocessors_onln();
340 case _SC_PHYS_PAGES: return __sysconf_phys_pages();
341 case _SC_AVPHYS_PAGES: return __sysconf_avphys_pages();
342
343 default:
344 /* Posix says EINVAL is the only error that shall be returned,
345 * but GLibc uses ENOSYS */
346 errno = ENOSYS;
347 return -1;
348 }
349 }
350