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 | |
23 | clock_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 | } |
60 | weak_alias (__times, times) |
61 | |