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 <errno.h>
30#include <fcntl.h>
31#include <limits.h>
32#include <linux/uio.h>  // For UIO_MAXIOV.
33#include <pthread.h>
34#include <stdio.h>  // For FOPEN_MAX.
35#include <sys/auxv.h>
36#include <sys/resource.h>
37#include <sys/sysconf.h>
38#include <sys/sysinfo.h>
39#include <time.h>
40#include <unistd.h>
41
42#include "private/bionic_tls.h"
43
44static long __sysconf_rlimit(int resource) {
45  rlimit rl;
46  getrlimit(resource, &rl);
47  return rl.rlim_cur;
48}
49
50long sysconf(int name) {
51  switch (name) {
52    case _SC_ARG_MAX:           return ARG_MAX;
53    case _SC_BC_BASE_MAX:       return _POSIX2_BC_BASE_MAX;   // Minimum requirement.
54    case _SC_BC_DIM_MAX:        return _POSIX2_BC_DIM_MAX;    // Minimum requirement.
55    case _SC_BC_SCALE_MAX:      return _POSIX2_BC_SCALE_MAX;  // Minimum requirement.
56    case _SC_BC_STRING_MAX:     return _POSIX2_BC_STRING_MAX; // Minimum requirement.
57    case _SC_CHILD_MAX:         return __sysconf_rlimit(RLIMIT_NPROC);
58    case _SC_CLK_TCK:           return static_cast<long>(getauxval(AT_CLKTCK));
59    case _SC_COLL_WEIGHTS_MAX:  return _POSIX2_COLL_WEIGHTS_MAX;  // Minimum requirement.
60    case _SC_EXPR_NEST_MAX:     return _POSIX2_EXPR_NEST_MAX;     // Minimum requirement.
61    case _SC_LINE_MAX:          return _POSIX2_LINE_MAX;          // Minimum requirement.
62    case _SC_NGROUPS_MAX:       return NGROUPS_MAX;
63    case _SC_OPEN_MAX:          return __sysconf_rlimit(RLIMIT_NOFILE);
64    case _SC_PASS_MAX:          return PASS_MAX;
65    case _SC_2_C_BIND:          return _POSIX2_C_BIND;
66    case _SC_2_C_DEV:           return _POSIX2_C_DEV;
67    case _SC_2_CHAR_TERM:       return _POSIX2_CHAR_TERM;
68    case _SC_2_FORT_DEV:        return -1;
69    case _SC_2_FORT_RUN:        return -1;
70    case _SC_2_LOCALEDEF:       return _POSIX2_LOCALEDEF;
71    case _SC_2_SW_DEV:          return _POSIX2_SW_DEV;
72    case _SC_2_UPE:             return _POSIX2_UPE;
73    case _SC_2_VERSION:         return _POSIX2_VERSION;
74    case _SC_JOB_CONTROL:       return _POSIX_JOB_CONTROL;
75    case _SC_SAVED_IDS:         return _POSIX_SAVED_IDS;
76    case _SC_VERSION:           return _POSIX_VERSION;
77    case _SC_RE_DUP_MAX:        return _POSIX_RE_DUP_MAX;         // Minimum requirement.
78    case _SC_STREAM_MAX:        return FOPEN_MAX;
79    case _SC_TZNAME_MAX:        return _POSIX_TZNAME_MAX;         // Minimum requirement.
80    case _SC_XOPEN_CRYPT:       return _XOPEN_CRYPT;
81    case _SC_XOPEN_ENH_I18N:    return _XOPEN_ENH_I18N;
82    case _SC_XOPEN_SHM:         return _XOPEN_SHM;
83    case _SC_XOPEN_VERSION:     return _XOPEN_VERSION;
84    case _SC_XOPEN_REALTIME:    return _XOPEN_REALTIME;
85    case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
86    case _SC_XOPEN_LEGACY:      return _XOPEN_LEGACY;
87    case _SC_ATEXIT_MAX:        return LONG_MAX;    // Unlimited.
88    case _SC_IOV_MAX:           return UIO_MAXIOV;
89
90    // _SC_PAGESIZE and _SC_PAGE_SIZE are distinct, but return the same value.
91    case _SC_PAGESIZE:
92    case _SC_PAGE_SIZE:
93      return static_cast<long>(getauxval(AT_PAGESZ));
94
95    case _SC_XOPEN_UNIX:        return _XOPEN_UNIX;
96    case _SC_AIO_LISTIO_MAX:    return _POSIX_AIO_LISTIO_MAX;     // Minimum requirement.
97    case _SC_AIO_MAX:           return _POSIX_AIO_MAX;            // Minimum requirement.
98    case _SC_AIO_PRIO_DELTA_MAX:return 0;                         // Minimum requirement.
99    case _SC_DELAYTIMER_MAX:    return INT_MAX;
100    case _SC_MQ_OPEN_MAX:       return _POSIX_MQ_OPEN_MAX;        // Minimum requirement.
101    case _SC_MQ_PRIO_MAX:       return _POSIX_MQ_PRIO_MAX;        // Minimum requirement.
102    case _SC_RTSIG_MAX:         return RTSIG_MAX;
103    case _SC_SEM_NSEMS_MAX:     return _POSIX_SEM_NSEMS_MAX;      // Minimum requirement.
104    case _SC_SEM_VALUE_MAX:     return SEM_VALUE_MAX;
105    case _SC_SIGQUEUE_MAX:      return _POSIX_SIGQUEUE_MAX;       // Minimum requirement.
106    case _SC_TIMER_MAX:         return _POSIX_TIMER_MAX;          // Minimum requirement.
107    case _SC_ASYNCHRONOUS_IO:   return _POSIX_ASYNCHRONOUS_IO;
108    case _SC_FSYNC:             return _POSIX_FSYNC;
109    case _SC_MAPPED_FILES:      return _POSIX_MAPPED_FILES;
110    case _SC_MEMLOCK:           return _POSIX_MEMLOCK;
111    case _SC_MEMLOCK_RANGE:     return _POSIX_MEMLOCK_RANGE;
112    case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
113    case _SC_MESSAGE_PASSING:   return _POSIX_MESSAGE_PASSING;
114    case _SC_PRIORITIZED_IO:    return _POSIX_PRIORITIZED_IO;
115    case _SC_PRIORITY_SCHEDULING:  return _POSIX_PRIORITY_SCHEDULING;
116    case _SC_REALTIME_SIGNALS:  return _POSIX_REALTIME_SIGNALS;
117    case _SC_SEMAPHORES:        return _POSIX_SEMAPHORES;
118    case _SC_SHARED_MEMORY_OBJECTS:  return _POSIX_SHARED_MEMORY_OBJECTS;
119    case _SC_SYNCHRONIZED_IO:   return _POSIX_SYNCHRONIZED_IO;
120    case _SC_TIMERS:            return _POSIX_TIMERS;
121    case _SC_GETGR_R_SIZE_MAX:  return 1024;
122    case _SC_GETPW_R_SIZE_MAX:  return 1024;
123    case _SC_LOGIN_NAME_MAX:    return 256;   // Seems default on linux.
124    case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS;
125    case _SC_THREAD_KEYS_MAX:   return PTHREAD_KEYS_MAX;
126    case _SC_THREAD_STACK_MIN:    return PTHREAD_STACK_MIN;
127    case _SC_THREAD_THREADS_MAX:  return PTHREAD_THREADS_MAX;
128    case _SC_TTY_NAME_MAX:        return 32;  // Seems default on linux.
129    case _SC_THREADS:             return _POSIX_THREADS;
130    case _SC_THREAD_ATTR_STACKADDR:   return _POSIX_THREAD_ATTR_STACKADDR;
131    case _SC_THREAD_ATTR_STACKSIZE:   return _POSIX_THREAD_ATTR_STACKSIZE;
132    case _SC_THREAD_PRIORITY_SCHEDULING:  return _POSIX_THREAD_PRIORITY_SCHEDULING;
133    case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT;
134    case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
135    case _SC_THREAD_SAFE_FUNCTIONS:  return _POSIX_THREAD_SAFE_FUNCTIONS;
136    case _SC_NPROCESSORS_CONF:  return get_nprocs_conf();
137    case _SC_NPROCESSORS_ONLN:  return get_nprocs();
138    case _SC_PHYS_PAGES:        return get_phys_pages();
139    case _SC_AVPHYS_PAGES:      return get_avphys_pages();
140    case _SC_MONOTONIC_CLOCK:   return _POSIX_VERSION;
141
142    case _SC_2_PBS:             return -1;     // Obsolescent in POSIX.1-2008.
143    case _SC_2_PBS_ACCOUNTING:  return -1;     // Obsolescent in POSIX.1-2008.
144    case _SC_2_PBS_CHECKPOINT:  return -1;     // Obsolescent in POSIX.1-2008.
145    case _SC_2_PBS_LOCATE:      return -1;     // Obsolescent in POSIX.1-2008.
146    case _SC_2_PBS_MESSAGE:     return -1;     // Obsolescent in POSIX.1-2008.
147    case _SC_2_PBS_TRACK:       return -1;     // Obsolescent in POSIX.1-2008.
148    case _SC_ADVISORY_INFO:     return _POSIX_ADVISORY_INFO;
149    case _SC_BARRIERS:          return _POSIX_BARRIERS;
150    case _SC_CLOCK_SELECTION:   return _POSIX_CLOCK_SELECTION;
151    case _SC_CPUTIME:           return _POSIX_VERSION;
152
153    case _SC_HOST_NAME_MAX:     return _POSIX_HOST_NAME_MAX;    // Minimum requirement.
154    case _SC_IPV6:              return _POSIX_IPV6;
155    case _SC_RAW_SOCKETS:       return _POSIX_RAW_SOCKETS;
156    case _SC_READER_WRITER_LOCKS: return _POSIX_READER_WRITER_LOCKS;
157    case _SC_REGEXP:            return _POSIX_REGEXP;
158    case _SC_SHELL:             return _POSIX_SHELL;
159    case _SC_SPAWN:             return _POSIX_SPAWN;
160    case _SC_SPIN_LOCKS:        return _POSIX_SPIN_LOCKS;
161    case _SC_SPORADIC_SERVER:   return _POSIX_SPORADIC_SERVER;
162    case _SC_SS_REPL_MAX:       return -1;
163    case _SC_SYMLOOP_MAX:       return _POSIX_SYMLOOP_MAX;      // Minimum requirement.
164    case _SC_THREAD_CPUTIME:    return _POSIX_VERSION;
165
166    case _SC_THREAD_PROCESS_SHARED: return _POSIX_THREAD_PROCESS_SHARED;
167    case _SC_THREAD_ROBUST_PRIO_INHERIT:  return _POSIX_THREAD_ROBUST_PRIO_INHERIT;
168    case _SC_THREAD_ROBUST_PRIO_PROTECT:  return _POSIX_THREAD_ROBUST_PRIO_PROTECT;
169    case _SC_THREAD_SPORADIC_SERVER:      return _POSIX_THREAD_SPORADIC_SERVER;
170    case _SC_TIMEOUTS:          return _POSIX_TIMEOUTS;
171    case _SC_TRACE:             return -1;             // Obsolescent in POSIX.1-2008.
172    case _SC_TRACE_EVENT_FILTER:      return -1;       // Obsolescent in POSIX.1-2008.
173    case _SC_TRACE_EVENT_NAME_MAX:    return -1;
174    case _SC_TRACE_INHERIT:     return -1;             // Obsolescent in POSIX.1-2008.
175    case _SC_TRACE_LOG:         return -1;             // Obsolescent in POSIX.1-2008.
176    case _SC_TRACE_NAME_MAX:    return -1;
177    case _SC_TRACE_SYS_MAX:     return -1;
178    case _SC_TRACE_USER_EVENT_MAX:    return -1;
179    case _SC_TYPED_MEMORY_OBJECTS:    return _POSIX_TYPED_MEMORY_OBJECTS;
180    case _SC_V7_ILP32_OFF32:    return _POSIX_V7_ILP32_OFF32;
181    case _SC_V7_ILP32_OFFBIG:   return _POSIX_V7_ILP32_OFFBIG;
182    case _SC_V7_LP64_OFF64:     return _POSIX_V7_LP64_OFF64;
183    case _SC_V7_LPBIG_OFFBIG:   return _POSIX_V7_LPBIG_OFFBIG;
184    case _SC_XOPEN_STREAMS:     return -1;            // Obsolescent in POSIX.1-2008.
185    case _SC_XOPEN_UUCP:        return -1;
186
187    // We do not have actual implementations for cache queries.
188    // It's valid to return 0 as the result is unknown.
189    case _SC_LEVEL1_ICACHE_SIZE:      return 0;
190    case _SC_LEVEL1_ICACHE_ASSOC:     return 0;
191    case _SC_LEVEL1_ICACHE_LINESIZE:  return 0;
192    case _SC_LEVEL1_DCACHE_SIZE:      return 0;
193    case _SC_LEVEL1_DCACHE_ASSOC:     return 0;
194    case _SC_LEVEL1_DCACHE_LINESIZE:  return 0;
195    case _SC_LEVEL2_CACHE_SIZE:       return 0;
196    case _SC_LEVEL2_CACHE_ASSOC:      return 0;
197    case _SC_LEVEL2_CACHE_LINESIZE:   return 0;
198    case _SC_LEVEL3_CACHE_SIZE:       return 0;
199    case _SC_LEVEL3_CACHE_ASSOC:      return 0;
200    case _SC_LEVEL3_CACHE_LINESIZE:   return 0;
201    case _SC_LEVEL4_CACHE_SIZE:       return 0;
202    case _SC_LEVEL4_CACHE_ASSOC:      return 0;
203    case _SC_LEVEL4_CACHE_LINESIZE:   return 0;
204
205    default:
206      // Posix says EINVAL is the only error that shall be returned,
207      // but glibc uses ENOSYS.
208      errno = ENOSYS;
209      return -1;
210  }
211}
212