mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-05 11:11:04 +00:00
04277e02d7
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
147 lines
3.8 KiB
C
147 lines
3.8 KiB
C
/* Get file-specific information about a file. Linux version.
|
|
Copyright (C) 2003-2019 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdlib.h>
|
|
#include <sysdep.h>
|
|
#include <time.h>
|
|
#include <unistd.h>
|
|
#include <sys/resource.h>
|
|
#include <sys/param.h>
|
|
#include <not-cancel.h>
|
|
#include <ldsodefs.h>
|
|
|
|
/* Legacy value of ARG_MAX. The macro is now not defined since the
|
|
actual value varies based on the stack size. */
|
|
#define legacy_ARG_MAX 131072
|
|
|
|
|
|
static long int posix_sysconf (int name);
|
|
|
|
|
|
#ifndef HAS_CPUCLOCK
|
|
static long int
|
|
has_cpuclock (int name)
|
|
{
|
|
# if defined __NR_clock_getres || HP_TIMING_AVAIL
|
|
/* If we have HP_TIMING, we will fall back on that if the system
|
|
call does not work, so we support it either way. */
|
|
# if !HP_TIMING_AVAIL
|
|
/* Check using the clock_getres system call. */
|
|
struct timespec ts;
|
|
INTERNAL_SYSCALL_DECL (err);
|
|
int r = INTERNAL_SYSCALL (clock_getres, err, 2,
|
|
(name == _SC_CPUTIME
|
|
? CLOCK_PROCESS_CPUTIME_ID
|
|
: CLOCK_THREAD_CPUTIME_ID),
|
|
&ts);
|
|
if (INTERNAL_SYSCALL_ERROR_P (r, err))
|
|
return -1;
|
|
# endif
|
|
return _POSIX_VERSION;
|
|
# else
|
|
return -1;
|
|
# endif
|
|
}
|
|
# define HAS_CPUCLOCK(name) has_cpuclock (name)
|
|
#endif
|
|
|
|
|
|
/* Get the value of the system variable NAME. */
|
|
long int
|
|
__sysconf (int name)
|
|
{
|
|
const char *procfname = NULL;
|
|
|
|
switch (name)
|
|
{
|
|
struct rlimit rlimit;
|
|
#ifdef __NR_clock_getres
|
|
case _SC_MONOTONIC_CLOCK:
|
|
/* Check using the clock_getres system call. */
|
|
{
|
|
struct timespec ts;
|
|
INTERNAL_SYSCALL_DECL (err);
|
|
int r;
|
|
r = INTERNAL_SYSCALL (clock_getres, err, 2, CLOCK_MONOTONIC, &ts);
|
|
return INTERNAL_SYSCALL_ERROR_P (r, err) ? -1 : _POSIX_VERSION;
|
|
}
|
|
#endif
|
|
|
|
case _SC_CPUTIME:
|
|
case _SC_THREAD_CPUTIME:
|
|
return HAS_CPUCLOCK (name);
|
|
|
|
case _SC_ARG_MAX:
|
|
/* Use getrlimit to get the stack limit. */
|
|
if (__getrlimit (RLIMIT_STACK, &rlimit) == 0)
|
|
return MAX (legacy_ARG_MAX, rlimit.rlim_cur / 4);
|
|
|
|
return legacy_ARG_MAX;
|
|
|
|
case _SC_NGROUPS_MAX:
|
|
/* Try to read the information from the /proc/sys/kernel/ngroups_max
|
|
file. */
|
|
procfname = "/proc/sys/kernel/ngroups_max";
|
|
break;
|
|
|
|
case _SC_SIGQUEUE_MAX:
|
|
if (__getrlimit (RLIMIT_SIGPENDING, &rlimit) == 0)
|
|
return rlimit.rlim_cur;
|
|
|
|
/* The /proc/sys/kernel/rtsig-max file contains the answer. */
|
|
procfname = "/proc/sys/kernel/rtsig-max";
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (procfname != NULL)
|
|
{
|
|
int fd = __open_nocancel (procfname, O_RDONLY);
|
|
if (fd != -1)
|
|
{
|
|
/* This is more than enough, the file contains a single integer. */
|
|
char buf[32];
|
|
ssize_t n;
|
|
n = TEMP_FAILURE_RETRY (__read_nocancel (fd, buf, sizeof (buf) - 1));
|
|
__close_nocancel_nostatus (fd);
|
|
|
|
if (n > 0)
|
|
{
|
|
/* Terminate the string. */
|
|
buf[n] = '\0';
|
|
|
|
char *endp;
|
|
long int res = strtol (buf, &endp, 10);
|
|
if (endp != buf && (*endp == '\0' || *endp == '\n'))
|
|
return res;
|
|
}
|
|
}
|
|
}
|
|
|
|
return posix_sysconf (name);
|
|
}
|
|
|
|
/* Now the POSIX version. */
|
|
#undef __sysconf
|
|
#define __sysconf static posix_sysconf
|
|
#include <sysdeps/posix/sysconf.c>
|