freebsd-nq/lib/libc/gen/sysconf.c
Edward Tomasz Napierala 3a9cdc5132 Make sysconf(_SC_PAGESIZE) return the value from getpagesize(3).
That avoids a syscall - getpagesize(3) gets the value from the ELF
aux strings.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D17989
2018-11-19 18:23:17 +00:00

619 lines
16 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Sean Eric Fagan of Cygnus Support.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/cdefs.h>
__SCCSID("@(#)sysconf.c 8.2 (Berkeley) 3/20/94");
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <elf.h>
#include <errno.h>
#include <limits.h>
#include <paths.h>
#include <pthread.h> /* we just need the limits */
#include <semaphore.h>
#include <time.h>
#include <unistd.h>
#include "un-namespace.h"
#include "../stdlib/atexit.h"
#include "tzfile.h" /* from ../../../contrib/tzcode/stdtime */
#include "libc_private.h"
#define _PATH_ZONEINFO TZDIR /* from tzfile.h */
/*
* sysconf --
* get configurable system variables.
*
* XXX
* POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
* not change during the lifetime of the calling process. This would seem
* to require that any change to system limits kill all running processes.
* A workaround might be to cache the values when they are first retrieved
* and then simply return the cached value on subsequent calls. This is
* less useful than returning up-to-date values, however.
*/
long
sysconf(int name)
{
struct rlimit rl;
size_t len;
int mib[2], sverrno, value;
long lvalue, defaultresult;
const char *path;
defaultresult = -1;
switch (name) {
case _SC_ARG_MAX:
mib[0] = CTL_KERN;
mib[1] = KERN_ARGMAX;
break;
case _SC_CHILD_MAX:
if (getrlimit(RLIMIT_NPROC, &rl) != 0)
return (-1);
if (rl.rlim_cur == RLIM_INFINITY)
return (-1);
if (rl.rlim_cur > LONG_MAX) {
errno = EOVERFLOW;
return (-1);
}
return ((long)rl.rlim_cur);
case _SC_CLK_TCK:
return (CLK_TCK);
case _SC_NGROUPS_MAX:
mib[0] = CTL_KERN;
mib[1] = KERN_NGROUPS;
break;
case _SC_OPEN_MAX:
if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
return (-1);
if (rl.rlim_cur == RLIM_INFINITY)
return (-1);
if (rl.rlim_cur > LONG_MAX) {
errno = EOVERFLOW;
return (-1);
}
return ((long)rl.rlim_cur);
case _SC_STREAM_MAX:
if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
return (-1);
if (rl.rlim_cur == RLIM_INFINITY)
return (-1);
if (rl.rlim_cur > LONG_MAX) {
errno = EOVERFLOW;
return (-1);
}
/*
* struct __sFILE currently has a limitation that
* file descriptors must fit in a signed short.
* This doesn't precisely capture the letter of POSIX
* but approximates the spirit.
*/
if (rl.rlim_cur > SHRT_MAX)
return (SHRT_MAX);
return ((long)rl.rlim_cur);
case _SC_JOB_CONTROL:
return (_POSIX_JOB_CONTROL);
case _SC_SAVED_IDS:
/* XXX - must be 1 */
mib[0] = CTL_KERN;
mib[1] = KERN_SAVED_IDS;
goto yesno;
case _SC_VERSION:
mib[0] = CTL_KERN;
mib[1] = KERN_POSIX1;
break;
case _SC_BC_BASE_MAX:
return (BC_BASE_MAX);
case _SC_BC_DIM_MAX:
return (BC_DIM_MAX);
case _SC_BC_SCALE_MAX:
return (BC_SCALE_MAX);
case _SC_BC_STRING_MAX:
return (BC_STRING_MAX);
case _SC_COLL_WEIGHTS_MAX:
return (COLL_WEIGHTS_MAX);
case _SC_EXPR_NEST_MAX:
return (EXPR_NEST_MAX);
case _SC_LINE_MAX:
return (LINE_MAX);
case _SC_RE_DUP_MAX:
return (RE_DUP_MAX);
case _SC_2_VERSION:
/*
* This is something of a lie, but it would be silly at
* this point to try to deduce this from the contents
* of the filesystem.
*/
return (_POSIX2_VERSION);
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 (_POSIX2_FORT_DEV);
case _SC_2_FORT_RUN:
return (_POSIX2_FORT_RUN);
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_TZNAME_MAX:
path = _PATH_ZONEINFO;
do_NAME_MAX:
sverrno = errno;
errno = 0;
lvalue = pathconf(path, _PC_NAME_MAX);
if (lvalue == -1 && errno != 0)
return (-1);
errno = sverrno;
return (lvalue);
case _SC_ASYNCHRONOUS_IO:
#if _POSIX_ASYNCHRONOUS_IO == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO;
break;
#else
return (_POSIX_ASYNCHRONOUS_IO);
#endif
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:
#if _POSIX_MESSAGE_PASSING == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_MESSAGE_PASSING;
goto yesno;
#else
return (_POSIX_MESSAGE_PASSING);
#endif
case _SC_PRIORITIZED_IO:
#if _POSIX_PRIORITIZED_IO == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_PRIORITIZED_IO;
goto yesno;
#else
return (_POSIX_PRIORITIZED_IO);
#endif
case _SC_PRIORITY_SCHEDULING:
#if _POSIX_PRIORITY_SCHEDULING == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING;
goto yesno;
#else
return (_POSIX_PRIORITY_SCHEDULING);
#endif
case _SC_REALTIME_SIGNALS:
#if _POSIX_REALTIME_SIGNALS == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_REALTIME_SIGNALS;
goto yesno;
#else
return (_POSIX_REALTIME_SIGNALS);
#endif
case _SC_SEMAPHORES:
#if _POSIX_SEMAPHORES == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_SEMAPHORES;
goto yesno;
#else
return (_POSIX_SEMAPHORES);
#endif
case _SC_FSYNC:
return (_POSIX_FSYNC);
case _SC_SHARED_MEMORY_OBJECTS:
return (_POSIX_SHARED_MEMORY_OBJECTS);
case _SC_SYNCHRONIZED_IO:
#if _POSIX_SYNCHRONIZED_IO == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO;
goto yesno;
#else
return (_POSIX_SYNCHRONIZED_IO);
#endif
case _SC_TIMERS:
#if _POSIX_TIMERS == 0
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_TIMERS;
goto yesno;
#else
return (_POSIX_TIMERS);
#endif
case _SC_AIO_LISTIO_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX;
break;
case _SC_AIO_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_AIO_MAX;
break;
case _SC_AIO_PRIO_DELTA_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX;
break;
case _SC_DELAYTIMER_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_DELAYTIMER_MAX;
goto yesno;
case _SC_MQ_OPEN_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_MQ_OPEN_MAX;
goto yesno;
case _SC_PAGESIZE:
return (getpagesize());
case _SC_RTSIG_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_RTSIG_MAX;
goto yesno;
case _SC_SEM_NSEMS_MAX:
return (-1);
case _SC_SEM_VALUE_MAX:
return (SEM_VALUE_MAX);
case _SC_SIGQUEUE_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_SIGQUEUE_MAX;
goto yesno;
case _SC_TIMER_MAX:
mib[0] = CTL_P1003_1B;
mib[1] = CTL_P1003_1B_TIMER_MAX;
yesno:
len = sizeof(value);
if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
return (-1);
if (value == 0)
return (defaultresult);
return ((long)value);
case _SC_2_PBS:
case _SC_2_PBS_ACCOUNTING:
case _SC_2_PBS_CHECKPOINT:
case _SC_2_PBS_LOCATE:
case _SC_2_PBS_MESSAGE:
case _SC_2_PBS_TRACK:
#if _POSIX2_PBS == 0
#error "don't know how to determine _SC_2_PBS"
/*
* This probably requires digging through the filesystem
* to see if the appropriate package has been installed.
* Since we don't currently support this option at all,
* it's not worth the effort to write the code now.
* Figuring out which of the sub-options are supported
* would be even more difficult, so it's probably easier
* to always say ``no''.
*/
#else
return (_POSIX2_PBS);
#endif
case _SC_ADVISORY_INFO:
#if _POSIX_ADVISORY_INFO == 0
#error "_POSIX_ADVISORY_INFO"
#else
return (_POSIX_ADVISORY_INFO);
#endif
case _SC_BARRIERS:
#if _POSIX_BARRIERS == 0
#error "_POSIX_BARRIERS"
#else
return (_POSIX_BARRIERS);
#endif
case _SC_CLOCK_SELECTION:
#if _POSIX_CLOCK_SELECTION == 0
#error "_POSIX_CLOCK_SELECTION"
#else
return (_POSIX_CLOCK_SELECTION);
#endif
case _SC_CPUTIME:
return (_POSIX_CPUTIME);
#ifdef notdef
case _SC_FILE_LOCKING:
/*
* XXX - The standard doesn't tell us how to define
* _POSIX_FILE_LOCKING, so we can't answer this one.
*/
#endif
/*
* SUSv4tc1 says the following about _SC_GETGR_R_SIZE_MAX and
* _SC_GETPW_R_SIZE_MAX:
* Note that sysconf(_SC_GETGR_R_SIZE_MAX) may return -1 if
* there is no hard limit on the size of the buffer needed to
* store all the groups returned.
*/
case _SC_GETGR_R_SIZE_MAX:
case _SC_GETPW_R_SIZE_MAX:
return (-1);
case _SC_HOST_NAME_MAX:
return (MAXHOSTNAMELEN - 1); /* does not include \0 */
case _SC_LOGIN_NAME_MAX:
return (MAXLOGNAME);
case _SC_MONOTONIC_CLOCK:
#if _POSIX_MONOTONIC_CLOCK == 0
#error "_POSIX_MONOTONIC_CLOCK"
#else
return (_POSIX_MONOTONIC_CLOCK);
#endif
#if _POSIX_MESSAGE_PASSING > -1
case _SC_MQ_PRIO_MAX:
return (MQ_PRIO_MAX);
#endif
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:
#if _POSIX_SPORADIC_SERVER == 0
#error "_POSIX_SPORADIC_SERVER"
#else
return (_POSIX_SPORADIC_SERVER);
#endif
case _SC_THREAD_ATTR_STACKADDR:
return (_POSIX_THREAD_ATTR_STACKADDR);
case _SC_THREAD_ATTR_STACKSIZE:
return (_POSIX_THREAD_ATTR_STACKSIZE);
case _SC_THREAD_CPUTIME:
return (_POSIX_THREAD_CPUTIME);
case _SC_THREAD_DESTRUCTOR_ITERATIONS:
return (PTHREAD_DESTRUCTOR_ITERATIONS);
case _SC_THREAD_KEYS_MAX:
return (PTHREAD_KEYS_MAX);
case _SC_THREAD_PRIO_INHERIT:
return (_POSIX_THREAD_PRIO_INHERIT);
case _SC_THREAD_PRIO_PROTECT:
return (_POSIX_THREAD_PRIO_PROTECT);
case _SC_THREAD_PRIORITY_SCHEDULING:
return (_POSIX_THREAD_PRIORITY_SCHEDULING);
case _SC_THREAD_PROCESS_SHARED:
return (_POSIX_THREAD_PROCESS_SHARED);
case _SC_THREAD_SAFE_FUNCTIONS:
return (_POSIX_THREAD_SAFE_FUNCTIONS);
case _SC_THREAD_STACK_MIN:
return (PTHREAD_STACK_MIN);
case _SC_THREAD_THREADS_MAX:
return (PTHREAD_THREADS_MAX); /* XXX wrong type! */
case _SC_TIMEOUTS:
return (_POSIX_TIMEOUTS);
case _SC_THREADS:
return (_POSIX_THREADS);
case _SC_TRACE:
#if _POSIX_TRACE == 0
#error "_POSIX_TRACE"
/* While you're implementing this, also do the ones below. */
#else
return (_POSIX_TRACE);
#endif
#if _POSIX_TRACE > -1
case _SC_TRACE_EVENT_FILTER:
return (_POSIX_TRACE_EVENT_FILTER);
case _SC_TRACE_INHERIT:
return (_POSIX_TRACE_INHERIT);
case _SC_TRACE_LOG:
return (_POSIX_TRACE_LOG);
#endif
case _SC_TTY_NAME_MAX:
path = _PATH_DEV;
goto do_NAME_MAX;
case _SC_TYPED_MEMORY_OBJECTS:
#if _POSIX_TYPED_MEMORY_OBJECTS == 0
#error "_POSIX_TYPED_MEMORY_OBJECTS"
#else
return (_POSIX_TYPED_MEMORY_OBJECTS);
#endif
case _SC_V6_ILP32_OFF32:
#if _V6_ILP32_OFF32 == 0
if (sizeof(int) * CHAR_BIT == 32 &&
sizeof(int) == sizeof(long) &&
sizeof(long) == sizeof(void *) &&
sizeof(void *) == sizeof(off_t))
return 1;
else
return -1;
#else
return (_V6_ILP32_OFF32);
#endif
case _SC_V6_ILP32_OFFBIG:
#if _V6_ILP32_OFFBIG == 0
if (sizeof(int) * CHAR_BIT == 32 &&
sizeof(int) == sizeof(long) &&
sizeof(long) == sizeof(void *) &&
sizeof(off_t) * CHAR_BIT >= 64)
return 1;
else
return -1;
#else
return (_V6_ILP32_OFFBIG);
#endif
case _SC_V6_LP64_OFF64:
#if _V6_LP64_OFF64 == 0
if (sizeof(int) * CHAR_BIT == 32 &&
sizeof(long) * CHAR_BIT == 64 &&
sizeof(long) == sizeof(void *) &&
sizeof(void *) == sizeof(off_t))
return 1;
else
return -1;
#else
return (_V6_LP64_OFF64);
#endif
case _SC_V6_LPBIG_OFFBIG:
#if _V6_LPBIG_OFFBIG == 0
if (sizeof(int) * CHAR_BIT >= 32 &&
sizeof(long) * CHAR_BIT >= 64 &&
sizeof(void *) * CHAR_BIT >= 64 &&
sizeof(off_t) * CHAR_BIT >= 64)
return 1;
else
return -1;
#else
return (_V6_LPBIG_OFFBIG);
#endif
case _SC_ATEXIT_MAX:
return (ATEXIT_SIZE);
case _SC_IOV_MAX:
mib[0] = CTL_KERN;
mib[1] = KERN_IOV_MAX;
break;
case _SC_XOPEN_CRYPT:
return (_XOPEN_CRYPT);
case _SC_XOPEN_ENH_I18N:
return (_XOPEN_ENH_I18N);
case _SC_XOPEN_LEGACY:
return (_XOPEN_LEGACY);
case _SC_XOPEN_REALTIME:
#if _XOPEN_REALTIME == 0
sverrno = errno;
value = sysconf(_SC_ASYNCHRONOUS_IO) > 0 &&
sysconf(_SC_MEMLOCK) > 0 &&
sysconf(_SC_MEMLOCK_RANGE) > 0 &&
sysconf(_SC_MESSAGE_PASSING) > 0 &&
sysconf(_SC_PRIORITY_SCHEDULING) > 0 &&
sysconf(_SC_REALTIME_SIGNALS) > 0 &&
sysconf(_SC_SEMAPHORES) > 0 &&
sysconf(_SC_SHARED_MEMORY_OBJECTS) > 0 &&
sysconf(_SC_SYNCHRONIZED_IO) > 0 &&
sysconf(_SC_TIMERS) > 0;
errno = sverrno;
if (value)
return (200112L);
else
return (-1);
#else
return (_XOPEN_REALTIME);
#endif
case _SC_XOPEN_REALTIME_THREADS:
#if _XOPEN_REALTIME_THREADS == 0
#error "_XOPEN_REALTIME_THREADS"
#else
return (_XOPEN_REALTIME_THREADS);
#endif
case _SC_XOPEN_SHM:
len = sizeof(lvalue);
sverrno = errno;
if (sysctlbyname("kern.ipc.shmmin", &lvalue, &len, NULL,
0) == -1) {
errno = sverrno;
return (-1);
}
errno = sverrno;
return (1);
case _SC_XOPEN_STREAMS:
return (_XOPEN_STREAMS);
case _SC_XOPEN_UNIX:
return (_XOPEN_UNIX);
#ifdef _XOPEN_VERSION
case _SC_XOPEN_VERSION:
return (_XOPEN_VERSION);
#endif
#ifdef _XOPEN_XCU_VERSION
case _SC_XOPEN_XCU_VERSION:
return (_XOPEN_XCU_VERSION);
#endif
case _SC_SYMLOOP_MAX:
return (MAXSYMLINKS);
case _SC_RAW_SOCKETS:
return (_POSIX_RAW_SOCKETS);
case _SC_IPV6:
#if _POSIX_IPV6 == 0
sverrno = errno;
value = _socket(PF_INET6, SOCK_DGRAM, 0);
errno = sverrno;
if (value >= 0) {
_close(value);
return (200112L);
} else
return (0);
#else
return (_POSIX_IPV6);
#endif
case _SC_NPROCESSORS_CONF:
case _SC_NPROCESSORS_ONLN:
if (_elf_aux_info(AT_NCPUS, &value, sizeof(value)) == 0)
return ((long)value);
mib[0] = CTL_HW;
mib[1] = HW_NCPU;
break;
#ifdef _SC_PHYS_PAGES
case _SC_PHYS_PAGES:
len = sizeof(lvalue);
if (sysctlbyname("hw.availpages", &lvalue, &len, NULL, 0) == -1)
return (-1);
return (lvalue);
#endif
#ifdef _SC_CPUSET_SIZE
case _SC_CPUSET_SIZE:
len = sizeof(value);
if (sysctlbyname("kern.sched.cpusetsize", &value, &len, NULL,
0) == -1)
return (-1);
return ((long)value);
#endif
default:
errno = EINVAL;
return (-1);
}
len = sizeof(value);
if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
value = -1;
return ((long)value);
}