1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32
33#include <sys/param.h>
34#include <sys/time.h>
35#include <sys/resource.h>
36
37#include <stdlib.h>
38#include <limits.h>
39#include <nlist.h>
40#include <kvm.h>
41
42#include "kvm_private.h"
43
44static struct nlist nl[] = {
45	{ .n_name = "_averunnable" },
46#define	X_AVERUNNABLE	0
47	{ .n_name = "_fscale" },
48#define	X_FSCALE	1
49	{ .n_name = "" },
50};
51
52/*
53 * kvm_getloadavg() -- Get system load averages, from live or dead kernels.
54 *
55 * Put `nelem' samples into `loadavg' array.
56 * Return number of samples retrieved, or -1 on error.
57 */
58int
59kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem)
60{
61	struct loadavg loadinfo;
62	int fscale, i;
63
64	if (ISALIVE(kd))
65		return (getloadavg(loadavg, nelem));
66
67	if (!kd->arch->ka_native(kd)) {
68		_kvm_err(kd, kd->program,
69		    "cannot read loadavg from non-native core");
70		return (-1);
71	}
72
73	if (kvm_nlist(kd, nl) != 0 && nl[X_AVERUNNABLE].n_type == 0) {
74		_kvm_err(kd, kd->program,
75		    "%s: no such symbol", nl[X_AVERUNNABLE].n_name);
76		return (-1);
77	}
78
79#define KREAD(kd, addr, obj) \
80	(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
81	if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) {
82		_kvm_err(kd, kd->program, "can't read averunnable");
83		return (-1);
84	}
85
86	/*
87	 * Old kernels have fscale separately; if not found assume
88	 * running new format.
89	 */
90	if (nl[X_FSCALE].n_type != 0 &&
91	    !KREAD(kd, nl[X_FSCALE].n_value, &fscale))
92		loadinfo.fscale = fscale;
93
94	nelem = MIN(nelem, (int)(sizeof(loadinfo.ldavg) / sizeof(fixpt_t)));
95	for (i = 0; i < nelem; i++)
96		loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
97	return (nelem);
98}
99