mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +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.
68 lines
2.5 KiB
C
68 lines
2.5 KiB
C
/* Copyright (C) 2008-2019 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 <sys/times.h>
|
|
#include <sysdep.h>
|
|
|
|
|
|
clock_t
|
|
__times (struct tms *buf)
|
|
{
|
|
INTERNAL_SYSCALL_DECL (err);
|
|
clock_t ret = INTERNAL_SYSCALL (times, err, 1, buf);
|
|
if (INTERNAL_SYSCALL_ERROR_P (ret, err)
|
|
&& __builtin_expect (INTERNAL_SYSCALL_ERRNO (ret, err) == EFAULT, 0)
|
|
&& buf)
|
|
{
|
|
/* This might be an error or not. For architectures which have no
|
|
separate return value and error indicators we cannot
|
|
distinguish a return value of e.g. (clock_t) -14 from -EFAULT.
|
|
Therefore the only course of action is to dereference the user
|
|
-supplied structure on a return of (clock_t) -14. This will crash
|
|
applications which pass in an invalid non-NULL BUF pointer.
|
|
Note that Linux allows BUF to be NULL in which case we skip this. */
|
|
#define touch(v) \
|
|
do { \
|
|
clock_t temp = v; \
|
|
asm volatile ("" : "+r" (temp)); \
|
|
v = temp; \
|
|
} while (0)
|
|
touch (buf->tms_utime);
|
|
touch (buf->tms_stime);
|
|
touch (buf->tms_cutime);
|
|
touch (buf->tms_cstime);
|
|
|
|
/* If we come here the memory is valid and the kernel did not
|
|
return an EFAULT error, but rather e.g. (clock_t) -14.
|
|
Return the value given by the kernel. */
|
|
}
|
|
|
|
/* On Linux this function never fails except with EFAULT.
|
|
POSIX says that returning a value (clock_t) -1 indicates an error,
|
|
but on Linux this is simply one of the valid clock values after
|
|
clock_t wraps. Therefore when we would return (clock_t) -1, we
|
|
instead return (clock_t) 0, and loose a tick of accuracy (having
|
|
returned 0 for two consecutive calls even though the clock
|
|
advanced). */
|
|
if (ret == (clock_t) -1)
|
|
return (clock_t) 0;
|
|
|
|
return ret;
|
|
}
|
|
weak_alias (__times, times)
|