waitid.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2012 Jukka A. Ukkonen
5 * All rights reserved.
6 *
7 * This software was developed by Jukka Ukkonen for FreeBSD.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/11/lib/libc/gen/waitid.c 330897 2018-03-14 03:19:51Z eadler $");
33
34#include "namespace.h"
35#include <sys/types.h>
36#include <sys/wait.h>
37#include <stddef.h>
38#include <string.h>
39#include <signal.h>
40#include <errno.h>
41#include "un-namespace.h"
42#include "libc_private.h"
43
44int __waitid(idtype_t, id_t, siginfo_t *, int);
45
46int
47__waitid(idtype_t idtype, id_t id, siginfo_t *info, int flags)
48{
49	int status;
50	pid_t ret;
51
52	ret = ((pid_t (*)(idtype_t, id_t, int *, int, struct __wrusage *,
53	    siginfo_t *))__libc_interposing[INTERPOS_wait6])(idtype, id,
54	    &status, flags, NULL, info);
55
56	/*
57	 * According to SUSv4, waitid() shall not return a PID when a
58	 * process is found, but only 0.  If a process was actually
59	 * found, siginfo_t fields si_signo and si_pid will be
60	 * non-zero.  In case WNOHANG was set in the flags and no
61	 * process was found those fields are set to zero using
62	 * memset() below.
63	 */
64	if (ret == 0 && info != NULL)
65		memset(info, 0, sizeof(*info));
66	else if (ret > 0)
67		ret = 0;
68	return (ret);
69}
70
71__weak_reference(__waitid, waitid);
72__weak_reference(__waitid, _waitid);
73