1/* Copyright (C) 2008-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <sys/times.h>
20#include <sysdep.h>
21
22
23clock_t
24__times (struct tms *buf)
25{
26 INTERNAL_SYSCALL_DECL (err);
27 clock_t ret = INTERNAL_SYSCALL (times, err, 1, buf);
28 if (INTERNAL_SYSCALL_ERROR_P (ret, err)
29 && __builtin_expect (INTERNAL_SYSCALL_ERRNO (ret, err) == EFAULT, 0)
30 && buf)
31 {
32 /* This might be an error or not. For architectures which have
33 no separate return value and error indicators we cannot
34 distinguish a return value of -1 from an error. Do it the
35 hard way. We crash applications which pass in an invalid
36 non-NULL BUF pointer. Linux allows BUF to be NULL. */
37#define touch(v) \
38 do { \
39 clock_t temp = v; \
40 asm volatile ("" : "+r" (temp)); \
41 v = temp; \
42 } while (0)
43 touch (buf->tms_utime);
44 touch (buf->tms_stime);
45 touch (buf->tms_cutime);
46 touch (buf->tms_cstime);
47
48 /* If we come here the memory is valid (or BUF is NULL, which is
49 a valid condition for the kernel syscall) and the kernel did not
50 return an EFAULT error. Return the value given by the kernel. */
51 }
52
53 /* Return value (clock_t) -1 signals an error, but if there wasn't any,
54 return the following value. */
55 if (ret == (clock_t) -1)
56 return (clock_t) 0;
57
58 return ret;
59}
60weak_alias (__times, times)
61