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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 #include <unistd.h>
29 #include <sys/sysconf.h>
30 #include <limits.h>
31 #include <bionic_tls.h>
32 #include <asm/page.h>
33 #include <stdio.h>  /* for FOPEN_MAX */
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <string.h>
37 #include <ctype.h>
38 
39 /* seems to be the default on Linux, per the GLibc sources and my own digging */
40 
41 #define  SYSTEM_CLK_TCK         100
42 #define  SYSTEM_IOV_MAX         1024
43 #define  SYSTEM_DELAYTIMER_MAX  2147483647
44 #define  SYSTEM_MQ_OPEN_MAX     8
45 #define  SYSTEM_MQ_PRIO_MAX     32768
46 #define  SYSTEM_SEM_NSEMS_MAX   256
47 #define  SYSTEM_SEM_VALUE_MAX   0x3fffffff  /* see bionic/semaphore.c */
48 #define  SYSTEM_SIGQUEUE_MAX    32
49 #define  SYSTEM_TIMER_MAX       32
50 #define  SYSTEM_LOGIN_NAME_MAX  256
51 #define  SYSTEM_TTY_NAME_MAX    32
52 
53 /* the following depends on our implementation */
54 #define  SYSTEM_ATEXIT_MAX          65536    /* our implementation is unlimited */
55 #define  SYSTEM_THREAD_KEYS_MAX     BIONIC_TLS_SLOTS
56 #define  SYSTEM_THREAD_STACK_MIN    32768    /* lower values may be possible, but be conservative */
57 #define  SYSTEM_THREAD_THREADS_MAX  2048     /* really unlimited */
58 
59 #define  SYSTEM_2_C_BIND     _POSIX_VERSION  /* Posix C binding version */
60 #define  SYSTEM_2_C_VER      _POSIX2_C_VERSION
61 #define  SYSTEM_2_C_DEV      -1       /* Posix C development tools unsupported on the device */
62 #define  SYSTEM_2_FORT_DEV   -1       /* Fortran development unsupported */
63 #define  SYSTEM_2_FORT_RUN   -1       /* Fortran runtime unsupported */
64 #define  SYSTEM_2_SW_DEV     -1       /* posix software dev utilities unsupported */
65 #define  SYSTEM_2_LOCALEDEF  -1       /* localdef() unimplemented */
66 #define  SYSTEM_2_UPE        -1       /* No UPE for you ! (User Portability Utilities) */
67 #define  SYSTEM_2_VERSION    -1       /* No posix command-line tools */
68 
69 static int  __get_nproc_conf(void);
70 static int  __get_nproc_onln(void);
71 static int  __get_phys_pages(void);
72 static int  __get_avphys_pages(void);
73 
74 int
sysconf(int name)75 sysconf( int  name )
76 {
77     switch (name) {
78 #ifdef _POSIX_ARG_MAX
79     case _SC_ARG_MAX:           return _POSIX_ARG_MAX;
80 #endif
81 #ifdef _POSIX2_BC_BASE_MAX
82     case _SC_BC_BASE_MAX:       return _POSIX2_BC_BASE_MAX;
83 #endif
84 #ifdef _POSIX2_BC_DIM_MAX
85     case _SC_BC_DIM_MAX:        return _POSIX2_BC_DIM_MAX;
86 #endif
87 #ifdef _POSIX2_BC_SCALE_MAX
88     case _SC_BC_SCALE_MAX:      return _POSIX2_BC_SCALE_MAX;
89 #endif
90 #ifdef _POSIX2_BC_STRING_MAX
91     case _SC_BC_STRING_MAX:     return _POSIX2_BC_STRING_MAX;
92 #endif
93     case _SC_CHILD_MAX:         return CHILD_MAX;
94     case _SC_CLK_TCK:           return SYSTEM_CLK_TCK;
95 #ifdef _POSIX2_COLL_WEIGHTS_MASK
96     case _SC_COLL_WEIGHTS_MAX:  return _POSIX2_COLL_WEIGHTS_MASK;
97 #endif
98 #ifdef _POSIX2_EXPR_NEST_MAX
99     case _SC_EXPR_NEST_MAX:    return _POSIX2_EXPR_NEST_MAX;
100 #endif
101 #ifdef _POSIX2_LINE_MAX
102     case _SC_LINE_MAX:          return _POSIX2_LINE_MAX;
103 #endif
104     case _SC_NGROUPS_MAX:       return NGROUPS_MAX;
105     case _SC_OPEN_MAX:          return OPEN_MAX;
106     //case _SC_PASS_MAX:          return PASS_MAX;
107     case _SC_2_C_BIND:          return SYSTEM_2_C_BIND;
108     case _SC_2_C_DEV:           return SYSTEM_2_C_DEV;
109     case _SC_2_C_VERSION:       return SYSTEM_2_C_VER;
110     //case _SC_2_CHAR_TERM:         return ;
111     case _SC_2_FORT_DEV:        return SYSTEM_2_FORT_DEV;
112     case _SC_2_FORT_RUN:        return SYSTEM_2_FORT_RUN;
113     case _SC_2_LOCALEDEF:       return SYSTEM_2_LOCALEDEF;
114     case _SC_2_SW_DEV:          return SYSTEM_2_SW_DEV;
115     case _SC_2_UPE:             return SYSTEM_2_UPE;
116     case _SC_2_VERSION:         return SYSTEM_2_VERSION;
117 #ifdef _POSIX_JOB_CONTROL
118     case _SC_JOB_CONTROL:       return _POSIX_JOB_CONTROL;
119 #endif
120 #ifdef _POSIX_SAVED_IDS
121     case _SC_SAVED_IDS:         return _POSIX_SAVED_IDS;
122 #endif
123 #ifdef _POSIX_VERSION
124     case _SC_VERSION:           return _POSIX_VERSION;
125 #endif
126     //case _SC_RE_DUP_<AX:        return ;
127     case _SC_STREAM_MAX:        return FOPEN_MAX;
128     //case _SC_TZNAME_MAX:        return ;
129 #if _XOPEN_CRYPT
130     case _SC_XOPEN_CRYPT:       return _XOPEN_CRYPT;
131 #endif
132 #ifdef _XOPEN_ENH_I18N
133     case _SC_XOPEN_ENH_I18N:    return _XOPEN_ENH_I18N;
134 #endif
135 #ifdef _XOPEN_SHM
136     case _SC_XOPEN_SHM:         return _XOPEN_SHM;
137 #endif
138 #ifdef _XOPEN_VERSION
139     case _SC_XOPEN_VERSION:     return _XOPEN_VERSION;
140 #endif
141 #ifdef _XOPEN_XCU_VERSION
142     case _SC_XOPEN_XCU_VERSION: return _XOPEN_XCU_VERSION;
143 #endif
144 #ifdef _XOPEN_REALTIME
145     case _SC_XOPEN_REALTIME:    return _XOPEN_REALTIME;
146 #endif
147 #ifdef _XOPEN_REALTIME_THREADS
148     case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
149 #endif
150 #ifdef _XOPEN_LEGACY
151     case _SC_XOPEN_LEGACY:      return _XOPEN_LEGACY;
152 #endif
153     case _SC_ATEXIT_MAX:        return SYSTEM_ATEXIT_MAX;
154     case _SC_IOV_MAX:           return SYSTEM_IOV_MAX;
155     case _SC_PAGESIZE:          return PAGE_SIZE;
156     case _SC_PAGE_SIZE:         return PAGE_SIZE;
157 #ifdef _XOPEN_UNIX
158     case _SC_XOPEN_UNIX:        return _XOPEN_UNIX;
159 #endif
160 
161     // XXX: TODO: XBS5 nonsense
162 
163 #ifdef AIO_LISTIO_MAX
164     case _SC_AIO_LISTIO_MAX:       return AIO_LISTIO_MAX;
165 #endif
166 #ifdef AIO_MAX
167     case _SC_AIO_MAX:              return AIO_MAX;
168 #endif
169 #ifdef AIO_PRIO_DELTA_MAX
170     case _SC_AIO_PRIO_DELTA_MAX:   return AIO_PRIO_DELTA_MAX;
171 #endif
172     case _SC_DELAYTIMER_MAX:    return SYSTEM_DELAYTIMER_MAX;
173     case _SC_MQ_OPEN_MAX:       return SYSTEM_MQ_OPEN_MAX;
174     case _SC_MQ_PRIO_MAX:       return SYSTEM_MQ_PRIO_MAX;
175     case _SC_RTSIG_MAX:         return RTSIG_MAX;
176     case _SC_SEM_NSEMS_MAX:     return SYSTEM_SEM_NSEMS_MAX;
177     case _SC_SEM_VALUE_MAX:     return SYSTEM_SEM_VALUE_MAX;
178     case _SC_SIGQUEUE_MAX:      return SYSTEM_SIGQUEUE_MAX;
179     case _SC_TIMER_MAX:         return SYSTEM_TIMER_MAX;
180 #ifdef _POSIX_ASYNCHRONOUS_IO
181     case _SC_ASYNCHRONOUS_IO:   return _POSIX_ASYNCHRONOUS_IO;
182 #endif
183 #ifdef _POSIX_FSYNC
184     case _SC_FSYNC:             return _POSIX_FSYNC;
185 #endif
186 #ifdef _POSIX_MAPPED_FILES
187     case _SC_MAPPED_FILES:      return _POSIX_MAPPED_FILES;
188 #endif
189 #ifdef _POSIX_MEMLOCK
190     case _SC_MEMLOCK:           return _POSIX_MEMLOCK;
191 #endif
192 #ifdef _POSIX_MEMLOCK_RANGE
193     case _SC_MEMLOCK_RANGE:     return _POSIX_MEMLOCK_RANGE
194 #endif
195 #ifdef _POSIX_MEMORY_PROTECTION
196     case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
197 #endif
198 #ifdef _POSIX_MESSAGE_PASSING
199     case _SC_MESSAGE_PASSING:   return _POSIX_MESSAGE_PASSING;
200 #endif
201 #ifdef _POSIX_PRIORITIZED_IO
202     case _SC_PRIORITIZED_IO:    return _POSIX_PRIORITIZED_IO;
203 #endif
204 #ifdef _POSIX_PRIORITY_SCHEDULING
205     case _SC_PRIORITY_SCHEDULING:  return _POSIX_PRIORITY_SCHEDULING;
206 #endif
207 #ifdef _POSIX_REALTIME_SIGNALS
208     case _SC_REALTIME_SIGNALS:  return _POSIX_REALTIME_SIGNALS;
209 #endif
210 #ifdef _POSIX_SEMAPHORES
211     case _SC_SEMAPHORES:        return _POSIX_SEMAPHORES;
212 #endif
213 #ifdef _POSIX_SHARED_MEMORY_OBJECTS
214     case _SC_SHARED_MEMORY_OBJECTS:  return _POSIX_SHARED_MEMORY_OBJECTS;
215 #endif
216 #ifdef _POSIX_SYNCHRONIZED_IO
217     case _SC_SYNCHRONIZED_IO:   return _POSIX_SYNCHRONIZED_IO;
218 #endif
219 #ifdef _POSIX_TIMERS
220     case _SC_TIMERS:            return _POSIX_TIMERS;
221 #endif
222 
223     // GETGR_R_SIZE_MAX ?
224     // GETPW_R_SIZE_MAX ?
225 
226     case _SC_LOGIN_NAME_MAX:    return SYSTEM_LOGIN_NAME_MAX;
227 #ifdef _POSIX_THREAD_DESTRUCTOR_ITERATIONS
228     case _SC_THREAD_DESTRUCTOR_ITERATIONS:  return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
229 #endif
230     case _SC_THREAD_KEYS_MAX:     return SYSTEM_THREAD_KEYS_MAX;
231     case _SC_THREAD_STACK_MIN:    return SYSTEM_THREAD_STACK_MIN;
232     case _SC_THREAD_THREADS_MAX:  return SYSTEM_THREAD_THREADS_MAX;
233     case _SC_TTY_NAME_MAX:        return SYSTEM_TTY_NAME_MAX;
234 #ifdef _POSIX_THREADS
235     case _SC_THREADS:             return _POSIX_THREADS;
236 #endif
237 #ifdef _POSIX_THREAD_ATTR_STACKADDR
238     case _SC_THREAD_ATTR_STACKADDR:   return _POSIX_THREAD_ATTR_STACKADDR;
239 #endif
240 #ifdef _POSIX_THREAD_ATTR_STACKSIZE
241     case _SC_THREAD_ATTR_STACKSIZE:   return _POSIX_THREAD_ATTR_STACKSIZE;
242 #endif
243 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
244     case _SC_THREAD_PRIORITY_SCHEDULING:  return _POSIX_THREAD_PRIORITY_SCHEDULING;
245 #endif
246 #ifdef _POSIX_THREAD_PRIO_INHERIT
247     case _SC_THREAD_PRIO_INHERIT:         return _POSIX_THREAD_PRIO_INHERIT;
248 #endif
249 #ifdef _POSIX_THREAD_PRIO_PROTECT
250     case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
251 #endif
252 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
253     case _SC_THREAD_SAFE_FUNCTIONS:  return _POSIX_THREAD_SAFE_FUNCTIONS
254 #endif
255 
256 
257     case _SC_NPROCESSORS_CONF:  return __get_nproc_conf();
258     case _SC_NPROCESSORS_ONLN:  return __get_nproc_onln();
259     case _SC_PHYS_PAGES:        return __get_phys_pages();
260     case _SC_AVPHYS_PAGES:      return __get_avphys_pages();
261 
262     default:
263        /* Posix says EINVAL is the only error that shall be returned,
264         * but GLibc uses ENOSYS */
265         errno = ENOSYS;
266         return -1;
267     }
268 }
269 
270 
271 typedef struct {
272     int   rpos;
273     int   len;
274     int   overflow;
275     int   fd;
276     int   in_len;
277     int   in_pos;
278     char  buff[128];
279     char  input[128];
280 } LineParser;
281 
282 static int
line_parser_init(LineParser * p,const char * path)283 line_parser_init( LineParser*  p, const char*  path )
284 {
285     p->rpos     = 0;
286     p->len      = (int)sizeof(p->buff);
287     p->overflow = 0;
288 
289     p->in_len   = 0;
290     p->in_pos   = 0;
291     p->fd       = open( path, O_RDONLY );
292 
293     return p->fd;
294 }
295 
296 
297 static int
line_parser_addc(LineParser * p,int c)298 line_parser_addc( LineParser*  p, int  c )
299 {
300     if (p->overflow) {
301         p->overflow = (c == '\n');
302         return 0;
303     }
304     if (p->rpos >= p->len) {
305         p->overflow = 1;
306         return 0;
307     }
308     if (c == '\n') {
309         p->buff[p->rpos] = 0;
310         p->rpos = 0;
311         return 1;
312     }
313     p->buff[p->rpos++] = (char) c;
314     return 0;
315 }
316 
317 static int
line_parser_getc(LineParser * p)318 line_parser_getc( LineParser*  p )
319 {
320     if (p->in_pos >= p->in_len) {
321         int  ret;
322 
323         p->in_len = p->in_pos = 0;
324         do {
325             ret = read(p->fd, p->input, sizeof(p->input));
326         } while (ret < 0 && errno == EINTR);
327 
328         if (ret <= 0)
329             return -1;
330 
331         p->in_len = ret;
332     }
333     return p->input[ p->in_pos++ ];
334 }
335 
336 static const char*
line_parser_gets(LineParser * p)337 line_parser_gets( LineParser*  p )
338 {
339     for (;;) {
340         for (;;) {
341             int  c = line_parser_getc(p);
342 
343             if (c < 0) {
344                 close(p->fd);
345                 p->fd = -1;
346                 return NULL;
347              }
348              if (line_parser_addc(p, c))
349                 return p->buff;
350         }
351     }
352 }
353 
354 static void
line_parser_done(LineParser * p)355 line_parser_done( LineParser* p )
356 {
357     if (p->fd >= 0) {
358         close(p->fd);
359         p->fd = -1;
360     }
361 }
362 
363 static int
__get_nproc_conf(void)364 __get_nproc_conf(void)
365 {
366     LineParser   parser[1];
367     const char*  p;
368     int          count = 0;
369 
370     if (line_parser_init(parser, "/proc/cpuinfo") < 0)
371         return 1;
372 
373     while ((p = line_parser_gets(parser))) {
374         if ( !memcmp(p, "processor", 9) )
375             count += 1;
376     }
377     return (count < 1) ? 1 : count;
378 }
379 
380 
381 static int
__get_nproc_onln(void)382 __get_nproc_onln(void)
383 {
384     LineParser   parser[1];
385     const char*  p;
386     int          count = 0;
387 
388     if (line_parser_init(parser, "/proc/stat") < 0)
389         return 1;
390 
391     while ((p = line_parser_gets(parser))) {
392         if ( !memcmp(p, "cpu", 3) && isdigit(p[3]) )
393             count += 1;
394     }
395     return (count < 1) ? 1 : count;
396 }
397 
398 static int
__get_phys_pages(void)399 __get_phys_pages(void)
400 {
401     LineParser   parser[1];
402     const char*  p;
403 
404     if (line_parser_init(parser, "/proc/meminfo") < 0)
405         return -2;  /* what ? */
406 
407     while ((p = line_parser_gets(parser))) {
408         long  total;
409         if ( sscanf(p, "MemTotal: %ld kB", &total) == 1 ) {
410             line_parser_done(parser);
411             return (int) (total / (PAGE_SIZE/1024));
412         }
413     }
414     return -3;
415 }
416 
417 static int
__get_avphys_pages(void)418 __get_avphys_pages(void)
419 {
420     LineParser   parser[1];
421     const char*  p;
422 
423     if (line_parser_init(parser, "/proc/meminfo") < 0)
424         return -1;  /* what ? */
425 
426     while ((p = line_parser_gets(parser))) {
427         long  total;
428         if ( sscanf(p, "MemFree: %ld kB", &total) == 1 ) {
429             line_parser_done(parser);
430             return (int) (total / (PAGE_SIZE/1024));
431         }
432     }
433     return -1;
434 }
435