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 <pthread.h> 33 #include <stdio.h> // For FOPEN_MAX. 34 #include <sys/auxv.h> 35 #include <sys/param.h> 36 #include <sys/resource.h> 37 #include <sys/sysinfo.h> 38 #include <time.h> 39 #include <unistd.h> 40 41 #include "private/bionic_tls.h" 42 43 static long __sysconf_rlimit(int resource) { 44 rlimit rl; 45 getrlimit(resource, &rl); 46 return rl.rlim_cur; 47 } 48 49 long sysconf(int name) { 50 switch (name) { 51 // 52 // Things we actually have to calculate... 53 // 54 case _SC_ARG_MAX: 55 // https://lkml.org/lkml/2017/11/15/813... 56 // 57 // I suspect a 128kB sysconf(_SC_ARG_MAX) is the sanest bet, simply 58 // because of that "conservative is better than aggressive". 59 // 60 // Especially since _technically_ we're still limiting things to that 61 // 128kB due to the single-string limit. 62 // 63 // Linus 64 return ARG_MAX; 65 66 case _SC_AVPHYS_PAGES: return get_avphys_pages(); 67 case _SC_CHILD_MAX: return __sysconf_rlimit(RLIMIT_NPROC); 68 case _SC_CLK_TCK: return static_cast<long>(getauxval(AT_CLKTCK)); 69 case _SC_NPROCESSORS_CONF: return get_nprocs_conf(); 70 case _SC_NPROCESSORS_ONLN: return get_nprocs(); 71 case _SC_OPEN_MAX: return __sysconf_rlimit(RLIMIT_NOFILE); 72 73 case _SC_PAGESIZE: 74 case _SC_PAGE_SIZE: 75 // _SC_PAGESIZE and _SC_PAGE_SIZE are distinct, but return the same value. 76 return static_cast<long>(getauxval(AT_PAGESZ)); 77 78 case _SC_PHYS_PAGES: return get_phys_pages(); 79 80 // 81 // Constants... 82 // 83 case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX; // Minimum requirement. 84 case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX; // Minimum requirement. 85 case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX; // Minimum requirement. 86 case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX; // Minimum requirement. 87 case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MAX; // Minimum requirement. 88 case _SC_EXPR_NEST_MAX: return _POSIX2_EXPR_NEST_MAX; // Minimum requirement. 89 case _SC_LINE_MAX: return _POSIX2_LINE_MAX; // Minimum requirement. 90 case _SC_NGROUPS_MAX: return NGROUPS_MAX; 91 case _SC_PASS_MAX: return PASS_MAX; 92 case _SC_2_C_BIND: return _POSIX2_C_BIND; 93 case _SC_2_C_DEV: return _POSIX2_C_DEV; 94 case _SC_2_CHAR_TERM: return _POSIX2_CHAR_TERM; 95 case _SC_2_FORT_DEV: return -1; 96 case _SC_2_FORT_RUN: return -1; 97 case _SC_2_LOCALEDEF: return _POSIX2_LOCALEDEF; 98 case _SC_2_SW_DEV: return _POSIX2_SW_DEV; 99 case _SC_2_UPE: return _POSIX2_UPE; 100 case _SC_2_VERSION: return _POSIX2_VERSION; 101 case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL; 102 case _SC_SAVED_IDS: return _POSIX_SAVED_IDS; 103 case _SC_VERSION: return _POSIX_VERSION; 104 case _SC_RE_DUP_MAX: return _POSIX_RE_DUP_MAX; // Minimum requirement. 105 case _SC_STREAM_MAX: return FOPEN_MAX; 106 case _SC_TZNAME_MAX: return _POSIX_TZNAME_MAX; // Minimum requirement. 107 case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT; 108 case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N; 109 case _SC_XOPEN_SHM: return _XOPEN_SHM; 110 case _SC_XOPEN_VERSION: return _XOPEN_VERSION; 111 case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME; 112 case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS; 113 case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY; 114 case _SC_ATEXIT_MAX: return LONG_MAX; // Unlimited. 115 case _SC_IOV_MAX: return IOV_MAX; 116 117 case _SC_XOPEN_UNIX: return _XOPEN_UNIX; 118 case _SC_AIO_LISTIO_MAX: return _POSIX_AIO_LISTIO_MAX; // Minimum requirement. 119 case _SC_AIO_MAX: return _POSIX_AIO_MAX; // Minimum requirement. 120 case _SC_AIO_PRIO_DELTA_MAX:return 0; // Minimum requirement. 121 case _SC_DELAYTIMER_MAX: return INT_MAX; 122 case _SC_MQ_OPEN_MAX: return _POSIX_MQ_OPEN_MAX; // Minimum requirement. 123 case _SC_MQ_PRIO_MAX: return _POSIX_MQ_PRIO_MAX; // Minimum requirement. 124 case _SC_RTSIG_MAX: return RTSIG_MAX; 125 case _SC_SEM_NSEMS_MAX: return _POSIX_SEM_NSEMS_MAX; // Minimum requirement. 126 case _SC_SEM_VALUE_MAX: return SEM_VALUE_MAX; 127 case _SC_SIGQUEUE_MAX: return _POSIX_SIGQUEUE_MAX; // Minimum requirement. 128 case _SC_TIMER_MAX: return _POSIX_TIMER_MAX; // Minimum requirement. 129 case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO; 130 case _SC_FSYNC: return _POSIX_FSYNC; 131 case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES; 132 case _SC_MEMLOCK: return _POSIX_MEMLOCK; 133 case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE; 134 case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION; 135 case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING; 136 case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO; 137 case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING; 138 case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS; 139 case _SC_SEMAPHORES: return _POSIX_SEMAPHORES; 140 case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS; 141 case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO; 142 case _SC_TIMERS: return _POSIX_TIMERS; 143 case _SC_GETGR_R_SIZE_MAX: return 1024; 144 case _SC_GETPW_R_SIZE_MAX: return 1024; 145 case _SC_LOGIN_NAME_MAX: return LOGIN_NAME_MAX; 146 case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS; 147 case _SC_THREAD_KEYS_MAX: return PTHREAD_KEYS_MAX; 148 case _SC_THREAD_STACK_MIN: return PTHREAD_STACK_MIN; 149 case _SC_THREAD_THREADS_MAX: return -1; // No specific limit. 150 case _SC_TTY_NAME_MAX: return TTY_NAME_MAX; 151 case _SC_THREADS: return _POSIX_THREADS; 152 case _SC_THREAD_ATTR_STACKADDR: return _POSIX_THREAD_ATTR_STACKADDR; 153 case _SC_THREAD_ATTR_STACKSIZE: return _POSIX_THREAD_ATTR_STACKSIZE; 154 case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING; 155 case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT; 156 case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT; 157 case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS; 158 case _SC_MONOTONIC_CLOCK: return _POSIX_MONOTONIC_CLOCK; 159 160 case _SC_2_PBS: return -1; // Obsolescent in POSIX.1-2008. 161 case _SC_2_PBS_ACCOUNTING: return -1; // Obsolescent in POSIX.1-2008. 162 case _SC_2_PBS_CHECKPOINT: return -1; // Obsolescent in POSIX.1-2008. 163 case _SC_2_PBS_LOCATE: return -1; // Obsolescent in POSIX.1-2008. 164 case _SC_2_PBS_MESSAGE: return -1; // Obsolescent in POSIX.1-2008. 165 case _SC_2_PBS_TRACK: return -1; // Obsolescent in POSIX.1-2008. 166 case _SC_ADVISORY_INFO: return _POSIX_ADVISORY_INFO; 167 case _SC_BARRIERS: return _POSIX_BARRIERS; 168 case _SC_CLOCK_SELECTION: return _POSIX_CLOCK_SELECTION; 169 case _SC_CPUTIME: return _POSIX_CPUTIME; 170 171 case _SC_HOST_NAME_MAX: return _POSIX_HOST_NAME_MAX; // Minimum requirement. 172 case _SC_IPV6: return _POSIX_IPV6; 173 case _SC_RAW_SOCKETS: return _POSIX_RAW_SOCKETS; 174 case _SC_READER_WRITER_LOCKS: return _POSIX_READER_WRITER_LOCKS; 175 case _SC_REGEXP: return _POSIX_REGEXP; 176 case _SC_SHELL: return _POSIX_SHELL; 177 case _SC_SPAWN: return _POSIX_SPAWN; 178 case _SC_SPIN_LOCKS: return _POSIX_SPIN_LOCKS; 179 case _SC_SPORADIC_SERVER: return _POSIX_SPORADIC_SERVER; 180 case _SC_SS_REPL_MAX: return -1; 181 case _SC_SYMLOOP_MAX: return _POSIX_SYMLOOP_MAX; // Minimum requirement. 182 case _SC_THREAD_CPUTIME: return _POSIX_THREAD_CPUTIME; 183 184 case _SC_THREAD_PROCESS_SHARED: return _POSIX_THREAD_PROCESS_SHARED; 185 case _SC_THREAD_ROBUST_PRIO_INHERIT: return _POSIX_THREAD_ROBUST_PRIO_INHERIT; 186 case _SC_THREAD_ROBUST_PRIO_PROTECT: return _POSIX_THREAD_ROBUST_PRIO_PROTECT; 187 case _SC_THREAD_SPORADIC_SERVER: return _POSIX_THREAD_SPORADIC_SERVER; 188 case _SC_TIMEOUTS: return _POSIX_TIMEOUTS; 189 case _SC_TRACE: return -1; // Obsolescent in POSIX.1-2008. 190 case _SC_TRACE_EVENT_FILTER: return -1; // Obsolescent in POSIX.1-2008. 191 case _SC_TRACE_EVENT_NAME_MAX: return -1; 192 case _SC_TRACE_INHERIT: return -1; // Obsolescent in POSIX.1-2008. 193 case _SC_TRACE_LOG: return -1; // Obsolescent in POSIX.1-2008. 194 case _SC_TRACE_NAME_MAX: return -1; 195 case _SC_TRACE_SYS_MAX: return -1; 196 case _SC_TRACE_USER_EVENT_MAX: return -1; 197 case _SC_TYPED_MEMORY_OBJECTS: return _POSIX_TYPED_MEMORY_OBJECTS; 198 case _SC_V7_ILP32_OFF32: return _POSIX_V7_ILP32_OFF32; 199 case _SC_V7_ILP32_OFFBIG: return _POSIX_V7_ILP32_OFFBIG; 200 case _SC_V7_LP64_OFF64: return _POSIX_V7_LP64_OFF64; 201 case _SC_V7_LPBIG_OFFBIG: return _POSIX_V7_LPBIG_OFFBIG; 202 case _SC_XOPEN_STREAMS: return -1; // Obsolescent in POSIX.1-2008. 203 case _SC_XOPEN_UUCP: return -1; 204 205 // We do not have actual implementations for cache queries. 206 // It's valid to return 0 as the result is unknown. 207 case _SC_LEVEL1_ICACHE_SIZE: return 0; 208 case _SC_LEVEL1_ICACHE_ASSOC: return 0; 209 case _SC_LEVEL1_ICACHE_LINESIZE: return 0; 210 case _SC_LEVEL1_DCACHE_SIZE: return 0; 211 case _SC_LEVEL1_DCACHE_ASSOC: return 0; 212 case _SC_LEVEL1_DCACHE_LINESIZE: return 0; 213 case _SC_LEVEL2_CACHE_SIZE: return 0; 214 case _SC_LEVEL2_CACHE_ASSOC: return 0; 215 case _SC_LEVEL2_CACHE_LINESIZE: return 0; 216 case _SC_LEVEL3_CACHE_SIZE: return 0; 217 case _SC_LEVEL3_CACHE_ASSOC: return 0; 218 case _SC_LEVEL3_CACHE_LINESIZE: return 0; 219 case _SC_LEVEL4_CACHE_SIZE: return 0; 220 case _SC_LEVEL4_CACHE_ASSOC: return 0; 221 case _SC_LEVEL4_CACHE_LINESIZE: return 0; 222 223 default: 224 // Posix says EINVAL is the only error that shall be returned, 225 // but glibc uses ENOSYS. 226 errno = ENOSYS; 227 return -1; 228 } 229 } 230
