1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2008 Yahoo!, Inc.
5 * All rights reserved.
6 * Written by: John Baldwin <jhb@FreeBSD.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/param.h>
34#include <sys/pcpu.h>
35#include <sys/resource.h>
36#include <sys/sysctl.h>
37#include <errno.h>
38#include <kvm.h>
39#include <limits.h>
40#include <stdlib.h>
41#include <string.h>
42
43#include "kvm_private.h"
44
45static struct nlist kvm_cp_time_nl[] = {
46	{ .n_name = "_cp_time" },		/* (deprecated) */
47	{ .n_name = NULL },
48};
49
50#define	NL_CP_TIME		0
51
52static int kvm_cp_time_cached;
53
54static int
55_kvm_cp_time_init(kvm_t *kd)
56{
57
58	if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
59		return (-1);
60	kvm_cp_time_cached = 1;
61	return (0);
62}
63
64static int
65getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
66{
67	size_t nlen;
68
69	nlen = len;
70	if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
71		_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
72		    strerror(errno));
73		return (-1);
74	}
75	if (nlen != len) {
76		_kvm_err(kd, kd->program, "sysctl %s has unexpected size",
77		    name);
78		return (-1);
79	}
80	return (0);
81}
82
83int
84kvm_getcptime(kvm_t *kd, long *cp_time)
85{
86	struct pcpu *pc;
87	int i, j, maxcpu;
88
89	if (kd == NULL) {
90		kvm_cp_time_cached = 0;
91		return (0);
92	}
93
94	if (ISALIVE(kd))
95		return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
96		    CPUSTATES));
97
98	if (!kd->arch->ka_native(kd)) {
99		_kvm_err(kd, kd->program,
100		    "cannot read cp_time from non-native core");
101		return (-1);
102	}
103
104	if (kvm_cp_time_cached == 0) {
105		if (_kvm_cp_time_init(kd) < 0)
106			return (-1);
107	}
108
109	/* If this kernel has a "cp_time[]" symbol, then just read that. */
110	if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
111		if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
112		    sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
113			_kvm_err(kd, kd->program, "cannot read cp_time array");
114			return (-1);
115		}
116		return (0);
117	}
118
119	/*
120	 * If we don't have that symbol, then we have to simulate
121	 * "cp_time[]" by adding up the individual times for each CPU.
122	 */
123	maxcpu = kvm_getmaxcpu(kd);
124	if (maxcpu < 0)
125		return (-1);
126	for (i = 0; i < CPUSTATES; i++)
127		cp_time[i] = 0;
128	for (i = 0; i < maxcpu; i++) {
129		pc = kvm_getpcpu(kd, i);
130		if (pc == NULL)
131			continue;
132		if (pc == (void *)-1)
133			return (-1);
134		for (j = 0; j < CPUSTATES; j++)
135			cp_time[j] += pc->pc_cp_time[j];
136		free(pc);
137	}
138	return (0);
139}
140