glibc/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
Adhemerval Zanella 7c7671767e linux: Use 64-bit time_t syscall on clock_getcputclockid
The syscall __NR_clock_getres_time64 (for 32-bit) or __NR_clock_getres
(for 64-bit) is used as default.  The 32-bit fallback is used iff
__ASSUME_TIME64_SYSCALLS is not defined, which assumes the kernel ABI
provides either __NR_rt_sigtimedwait (32-bit time_t).

Since the symbol does not use any type which might be affected by the
time_t, there is no need to add a 64-bit variant.

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-09-28 16:21:55 -03:00

61 lines
2.1 KiB
C

/* clock_getcpuclockid -- Get a clockid_t for process CPU time. Linux version.
Copyright (C) 2004-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <time.h>
#include <unistd.h>
#include "kernel-posix-cpu-timers.h"
#include <shlib-compat.h>
int
__clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
{
/* The clockid_t value is a simple computation from the PID.
But we do a clock_getres call to validate it. */
const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED);
#ifndef __NR_clock_getres_time64
# define __NR_clock_getres_time64 __NR_clock_getres
#endif
int r = INTERNAL_SYSCALL_CALL (clock_getres_time64, pidclock, NULL);
#ifndef __ASSUME_TIME64_SYSCALLS
if (r != 0 && r == -ENOSYS)
r = INTERNAL_SYSCALL_CALL (clock_getres, pidclock, NULL);
#endif
if (r == 0)
{
*clock_id = pidclock;
return 0;
}
if (r == -EINVAL)
/* The clock_getres system call checked the PID for us. */
return ESRCH;
return -r;
}
versioned_symbol (libc, __clock_getcpuclockid, clock_getcpuclockid, GLIBC_2_17);
/* clock_getcpuclockid moved to libc in version 2.17;
old binaries may expect the symbol version it had in librt. */
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
strong_alias (__clock_getcpuclockid, __clock_getcpuclockid_2);
compat_symbol (libc, __clock_getcpuclockid_2, clock_getcpuclockid, GLIBC_2_2);
#endif