|  | /* | 
|  | * Copyright (C) 2008 The Android Open Source Project | 
|  | * All rights reserved. | 
|  | * | 
|  | * Redistribution and use in source and binary forms, with or without | 
|  | * modification, are permitted provided that the following conditions | 
|  | * are met: | 
|  | *  * Redistributions of source code must retain the above copyright | 
|  | *    notice, this list of conditions and the following disclaimer. | 
|  | *  * Redistributions in binary form must reproduce the above copyright | 
|  | *    notice, this list of conditions and the following disclaimer in | 
|  | *    the documentation and/or other materials provided with the | 
|  | *    distribution. | 
|  | * | 
|  | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
|  | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
|  | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | 
|  | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | 
|  | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | 
|  | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, | 
|  | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS | 
|  | * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED | 
|  | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | 
|  | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | 
|  | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | 
|  | * SUCH DAMAGE. | 
|  | */ | 
|  |  | 
|  | #include <errno.h> | 
|  | #include <fcntl.h> | 
|  | #include <limits.h> | 
|  | #include <pthread.h> | 
|  | #include <stdio.h>  // For FOPEN_MAX. | 
|  | #include <sys/auxv.h> | 
|  | #include <sys/param.h> | 
|  | #include <sys/resource.h> | 
|  | #include <sys/sysinfo.h> | 
|  | #include <time.h> | 
|  | #include <unistd.h> | 
|  |  | 
|  | #include "private/bionic_tls.h" | 
|  |  | 
|  | static long __sysconf_rlimit(int resource) { | 
|  | rlimit rl; | 
|  | getrlimit(resource, &rl); | 
|  | return rl.rlim_cur; | 
|  | } | 
|  |  | 
|  | long sysconf(int name) { | 
|  | switch (name) { | 
|  | // | 
|  | // Things we actually have to calculate... | 
|  | // | 
|  | case _SC_ARG_MAX: | 
|  | // Not a constant since Linux 2.6.23; see fs/exec.c for details. | 
|  | // At least 32 pages, otherwise a quarter of the stack limit. | 
|  | return MAX(__sysconf_rlimit(RLIMIT_STACK) / 4, _KERNEL_ARG_MAX); | 
|  |  | 
|  | case _SC_AVPHYS_PAGES:      return get_avphys_pages(); | 
|  | case _SC_CHILD_MAX:         return __sysconf_rlimit(RLIMIT_NPROC); | 
|  | case _SC_CLK_TCK:           return static_cast<long>(getauxval(AT_CLKTCK)); | 
|  | case _SC_NPROCESSORS_CONF:  return get_nprocs_conf(); | 
|  | case _SC_NPROCESSORS_ONLN:  return get_nprocs(); | 
|  | case _SC_OPEN_MAX:          return __sysconf_rlimit(RLIMIT_NOFILE); | 
|  |  | 
|  | case _SC_PAGESIZE: | 
|  | case _SC_PAGE_SIZE: | 
|  | // _SC_PAGESIZE and _SC_PAGE_SIZE are distinct, but return the same value. | 
|  | return static_cast<long>(getauxval(AT_PAGESZ)); | 
|  |  | 
|  | case _SC_PHYS_PAGES:        return get_phys_pages(); | 
|  |  | 
|  | // | 
|  | // Constants... | 
|  | // | 
|  | case _SC_BC_BASE_MAX:       return _POSIX2_BC_BASE_MAX;   // Minimum requirement. | 
|  | case _SC_BC_DIM_MAX:        return _POSIX2_BC_DIM_MAX;    // Minimum requirement. | 
|  | case _SC_BC_SCALE_MAX:      return _POSIX2_BC_SCALE_MAX;  // Minimum requirement. | 
|  | case _SC_BC_STRING_MAX:     return _POSIX2_BC_STRING_MAX; // Minimum requirement. | 
|  | case _SC_COLL_WEIGHTS_MAX:  return _POSIX2_COLL_WEIGHTS_MAX;  // Minimum requirement. | 
|  | case _SC_EXPR_NEST_MAX:     return _POSIX2_EXPR_NEST_MAX;     // Minimum requirement. | 
|  | case _SC_LINE_MAX:          return _POSIX2_LINE_MAX;          // Minimum requirement. | 
|  | case _SC_NGROUPS_MAX:       return NGROUPS_MAX; | 
|  | case _SC_PASS_MAX:          return PASS_MAX; | 
|  | case _SC_2_C_BIND:          return _POSIX2_C_BIND; | 
|  | case _SC_2_C_DEV:           return _POSIX2_C_DEV; | 
|  | case _SC_2_CHAR_TERM:       return _POSIX2_CHAR_TERM; | 
|  | case _SC_2_FORT_DEV:        return -1; | 
|  | case _SC_2_FORT_RUN:        return -1; | 
|  | case _SC_2_LOCALEDEF:       return _POSIX2_LOCALEDEF; | 
|  | case _SC_2_SW_DEV:          return _POSIX2_SW_DEV; | 
|  | case _SC_2_UPE:             return _POSIX2_UPE; | 
|  | case _SC_2_VERSION:         return _POSIX2_VERSION; | 
|  | case _SC_JOB_CONTROL:       return _POSIX_JOB_CONTROL; | 
|  | case _SC_SAVED_IDS:         return _POSIX_SAVED_IDS; | 
|  | case _SC_VERSION:           return _POSIX_VERSION; | 
|  | case _SC_RE_DUP_MAX:        return _POSIX_RE_DUP_MAX;         // Minimum requirement. | 
|  | case _SC_STREAM_MAX:        return FOPEN_MAX; | 
|  | case _SC_TZNAME_MAX:        return _POSIX_TZNAME_MAX;         // Minimum requirement. | 
|  | case _SC_XOPEN_CRYPT:       return _XOPEN_CRYPT; | 
|  | case _SC_XOPEN_ENH_I18N:    return _XOPEN_ENH_I18N; | 
|  | case _SC_XOPEN_SHM:         return _XOPEN_SHM; | 
|  | case _SC_XOPEN_VERSION:     return _XOPEN_VERSION; | 
|  | case _SC_XOPEN_REALTIME:    return _XOPEN_REALTIME; | 
|  | case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS; | 
|  | case _SC_XOPEN_LEGACY:      return _XOPEN_LEGACY; | 
|  | case _SC_ATEXIT_MAX:        return LONG_MAX;    // Unlimited. | 
|  | case _SC_IOV_MAX:           return IOV_MAX; | 
|  |  | 
|  | case _SC_XOPEN_UNIX:        return _XOPEN_UNIX; | 
|  | case _SC_AIO_LISTIO_MAX:    return _POSIX_AIO_LISTIO_MAX;     // Minimum requirement. | 
|  | case _SC_AIO_MAX:           return _POSIX_AIO_MAX;            // Minimum requirement. | 
|  | case _SC_AIO_PRIO_DELTA_MAX:return 0;                         // Minimum requirement. | 
|  | case _SC_DELAYTIMER_MAX:    return INT_MAX; | 
|  | case _SC_MQ_OPEN_MAX:       return _POSIX_MQ_OPEN_MAX;        // Minimum requirement. | 
|  | case _SC_MQ_PRIO_MAX:       return _POSIX_MQ_PRIO_MAX;        // Minimum requirement. | 
|  | case _SC_RTSIG_MAX:         return RTSIG_MAX; | 
|  | case _SC_SEM_NSEMS_MAX:     return _POSIX_SEM_NSEMS_MAX;      // Minimum requirement. | 
|  | case _SC_SEM_VALUE_MAX:     return SEM_VALUE_MAX; | 
|  | case _SC_SIGQUEUE_MAX:      return _POSIX_SIGQUEUE_MAX;       // Minimum requirement. | 
|  | case _SC_TIMER_MAX:         return _POSIX_TIMER_MAX;          // Minimum requirement. | 
|  | case _SC_ASYNCHRONOUS_IO:   return _POSIX_ASYNCHRONOUS_IO; | 
|  | case _SC_FSYNC:             return _POSIX_FSYNC; | 
|  | case _SC_MAPPED_FILES:      return _POSIX_MAPPED_FILES; | 
|  | case _SC_MEMLOCK:           return _POSIX_MEMLOCK; | 
|  | case _SC_MEMLOCK_RANGE:     return _POSIX_MEMLOCK_RANGE; | 
|  | case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION; | 
|  | case _SC_MESSAGE_PASSING:   return _POSIX_MESSAGE_PASSING; | 
|  | case _SC_PRIORITIZED_IO:    return _POSIX_PRIORITIZED_IO; | 
|  | case _SC_PRIORITY_SCHEDULING:  return _POSIX_PRIORITY_SCHEDULING; | 
|  | case _SC_REALTIME_SIGNALS:  return _POSIX_REALTIME_SIGNALS; | 
|  | case _SC_SEMAPHORES:        return _POSIX_SEMAPHORES; | 
|  | case _SC_SHARED_MEMORY_OBJECTS:  return _POSIX_SHARED_MEMORY_OBJECTS; | 
|  | case _SC_SYNCHRONIZED_IO:   return _POSIX_SYNCHRONIZED_IO; | 
|  | case _SC_TIMERS:            return _POSIX_TIMERS; | 
|  | case _SC_GETGR_R_SIZE_MAX:  return 1024; | 
|  | case _SC_GETPW_R_SIZE_MAX:  return 1024; | 
|  | case _SC_LOGIN_NAME_MAX:    return LOGIN_NAME_MAX; | 
|  | case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS; | 
|  | case _SC_THREAD_KEYS_MAX:   return PTHREAD_KEYS_MAX; | 
|  | case _SC_THREAD_STACK_MIN:    return PTHREAD_STACK_MIN; | 
|  | case _SC_THREAD_THREADS_MAX:  return -1; // No specific limit. | 
|  | case _SC_TTY_NAME_MAX:        return TTY_NAME_MAX; | 
|  | case _SC_THREADS:             return _POSIX_THREADS; | 
|  | case _SC_THREAD_ATTR_STACKADDR:   return _POSIX_THREAD_ATTR_STACKADDR; | 
|  | case _SC_THREAD_ATTR_STACKSIZE:   return _POSIX_THREAD_ATTR_STACKSIZE; | 
|  | case _SC_THREAD_PRIORITY_SCHEDULING:  return _POSIX_THREAD_PRIORITY_SCHEDULING; | 
|  | case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT; | 
|  | case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT; | 
|  | case _SC_THREAD_SAFE_FUNCTIONS:  return _POSIX_THREAD_SAFE_FUNCTIONS; | 
|  | case _SC_MONOTONIC_CLOCK:   return _POSIX_VERSION; | 
|  |  | 
|  | case _SC_2_PBS:             return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_2_PBS_ACCOUNTING:  return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_2_PBS_CHECKPOINT:  return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_2_PBS_LOCATE:      return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_2_PBS_MESSAGE:     return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_2_PBS_TRACK:       return -1;     // Obsolescent in POSIX.1-2008. | 
|  | case _SC_ADVISORY_INFO:     return _POSIX_ADVISORY_INFO; | 
|  | case _SC_BARRIERS:          return _POSIX_BARRIERS; | 
|  | case _SC_CLOCK_SELECTION:   return _POSIX_CLOCK_SELECTION; | 
|  | case _SC_CPUTIME:           return _POSIX_VERSION; | 
|  |  | 
|  | case _SC_HOST_NAME_MAX:     return _POSIX_HOST_NAME_MAX;    // Minimum requirement. | 
|  | case _SC_IPV6:              return _POSIX_IPV6; | 
|  | case _SC_RAW_SOCKETS:       return _POSIX_RAW_SOCKETS; | 
|  | case _SC_READER_WRITER_LOCKS: return _POSIX_READER_WRITER_LOCKS; | 
|  | case _SC_REGEXP:            return _POSIX_REGEXP; | 
|  | case _SC_SHELL:             return _POSIX_SHELL; | 
|  | case _SC_SPAWN:             return _POSIX_SPAWN; | 
|  | case _SC_SPIN_LOCKS:        return _POSIX_SPIN_LOCKS; | 
|  | case _SC_SPORADIC_SERVER:   return _POSIX_SPORADIC_SERVER; | 
|  | case _SC_SS_REPL_MAX:       return -1; | 
|  | case _SC_SYMLOOP_MAX:       return _POSIX_SYMLOOP_MAX;      // Minimum requirement. | 
|  | case _SC_THREAD_CPUTIME:    return _POSIX_VERSION; | 
|  |  | 
|  | case _SC_THREAD_PROCESS_SHARED: return _POSIX_THREAD_PROCESS_SHARED; | 
|  | case _SC_THREAD_ROBUST_PRIO_INHERIT:  return _POSIX_THREAD_ROBUST_PRIO_INHERIT; | 
|  | case _SC_THREAD_ROBUST_PRIO_PROTECT:  return _POSIX_THREAD_ROBUST_PRIO_PROTECT; | 
|  | case _SC_THREAD_SPORADIC_SERVER:      return _POSIX_THREAD_SPORADIC_SERVER; | 
|  | case _SC_TIMEOUTS:          return _POSIX_TIMEOUTS; | 
|  | case _SC_TRACE:             return -1;             // Obsolescent in POSIX.1-2008. | 
|  | case _SC_TRACE_EVENT_FILTER:      return -1;       // Obsolescent in POSIX.1-2008. | 
|  | case _SC_TRACE_EVENT_NAME_MAX:    return -1; | 
|  | case _SC_TRACE_INHERIT:     return -1;             // Obsolescent in POSIX.1-2008. | 
|  | case _SC_TRACE_LOG:         return -1;             // Obsolescent in POSIX.1-2008. | 
|  | case _SC_TRACE_NAME_MAX:    return -1; | 
|  | case _SC_TRACE_SYS_MAX:     return -1; | 
|  | case _SC_TRACE_USER_EVENT_MAX:    return -1; | 
|  | case _SC_TYPED_MEMORY_OBJECTS:    return _POSIX_TYPED_MEMORY_OBJECTS; | 
|  | case _SC_V7_ILP32_OFF32:    return _POSIX_V7_ILP32_OFF32; | 
|  | case _SC_V7_ILP32_OFFBIG:   return _POSIX_V7_ILP32_OFFBIG; | 
|  | case _SC_V7_LP64_OFF64:     return _POSIX_V7_LP64_OFF64; | 
|  | case _SC_V7_LPBIG_OFFBIG:   return _POSIX_V7_LPBIG_OFFBIG; | 
|  | case _SC_XOPEN_STREAMS:     return -1;            // Obsolescent in POSIX.1-2008. | 
|  | case _SC_XOPEN_UUCP:        return -1; | 
|  |  | 
|  | // We do not have actual implementations for cache queries. | 
|  | // It's valid to return 0 as the result is unknown. | 
|  | case _SC_LEVEL1_ICACHE_SIZE:      return 0; | 
|  | case _SC_LEVEL1_ICACHE_ASSOC:     return 0; | 
|  | case _SC_LEVEL1_ICACHE_LINESIZE:  return 0; | 
|  | case _SC_LEVEL1_DCACHE_SIZE:      return 0; | 
|  | case _SC_LEVEL1_DCACHE_ASSOC:     return 0; | 
|  | case _SC_LEVEL1_DCACHE_LINESIZE:  return 0; | 
|  | case _SC_LEVEL2_CACHE_SIZE:       return 0; | 
|  | case _SC_LEVEL2_CACHE_ASSOC:      return 0; | 
|  | case _SC_LEVEL2_CACHE_LINESIZE:   return 0; | 
|  | case _SC_LEVEL3_CACHE_SIZE:       return 0; | 
|  | case _SC_LEVEL3_CACHE_ASSOC:      return 0; | 
|  | case _SC_LEVEL3_CACHE_LINESIZE:   return 0; | 
|  | case _SC_LEVEL4_CACHE_SIZE:       return 0; | 
|  | case _SC_LEVEL4_CACHE_ASSOC:      return 0; | 
|  | case _SC_LEVEL4_CACHE_LINESIZE:   return 0; | 
|  |  | 
|  | default: | 
|  | // Posix says EINVAL is the only error that shall be returned, | 
|  | // but glibc uses ENOSYS. | 
|  | errno = ENOSYS; | 
|  | return -1; | 
|  | } | 
|  | } |