1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1999, Matthew Dillon. All Rights Reserved.
5 * Copyright (c) 2001, Thomas Moestl. 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 *
16 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/time.h>
31 #include <sys/stat.h>
32 #include <sys/blist.h>
33 #include <sys/queue.h>
34 #include <sys/sysctl.h>
35
36 #include <vm/swap_pager.h>
37 #include <vm/vm_param.h>
38
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <kvm.h>
43 #include <nlist.h>
44 #include <paths.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <limits.h>
50
51 #include "kvm_private.h"
52
53 static struct nlist kvm_swap_nl[] = {
54 { .n_name = "_swtailq" }, /* list of swap devices and sizes */
55 { .n_name = "_dmmax" }, /* maximum size of a swap block */
56 { .n_name = NULL }
57 };
58
59 #define NL_SWTAILQ 0
60 #define NL_DMMAX 1
61
62 static int kvm_swap_nl_cached = 0;
63 static int unswdev; /* number of found swap dev's */
64 static int dmmax;
65
66 static int kvm_getswapinfo_kvm(kvm_t *, struct kvm_swap *, int, int);
67 static int kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int);
68 static int nlist_init(kvm_t *);
69 static int getsysctl(kvm_t *, const char *, void *, size_t);
70
71 #define KREAD(kd, addr, obj) \
72 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
73 #define KGET(idx, var) \
74 KGET2(kvm_swap_nl[(idx)].n_value, var, kvm_swap_nl[(idx)].n_name)
75 #define KGET2(addr, var, msg) \
76 if (KREAD(kd, (u_long)(addr), (var))) { \
77 _kvm_err(kd, kd->program, "cannot read %s", msg); \
78 return (-1); \
79 }
80
81 #define GETSWDEVNAME(dev, str, flags) \
82 if (dev == NODEV) { \
83 strlcpy(str, "[NFS swap]", sizeof(str)); \
84 } else { \
85 snprintf( \
86 str, sizeof(str),"%s%s", \
87 ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""), \
88 devname(dev, S_IFCHR) \
89 ); \
90 }
91
92 int
kvm_getswapinfo(kvm_t * kd,struct kvm_swap * swap_ary,int swap_max,int flags)93 kvm_getswapinfo(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags)
94 {
95
96 /*
97 * clear cache
98 */
99 if (kd == NULL) {
100 kvm_swap_nl_cached = 0;
101 return(0);
102 }
103
104 if (ISALIVE(kd)) {
105 return kvm_getswapinfo_sysctl(kd, swap_ary, swap_max, flags);
106 } else {
107 return kvm_getswapinfo_kvm(kd, swap_ary, swap_max, flags);
108 }
109 }
110
111 int
kvm_getswapinfo_kvm(kvm_t * kd,struct kvm_swap * swap_ary,int swap_max,int flags)112 kvm_getswapinfo_kvm(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max,
113 int flags)
114 {
115 int i, ttl;
116 TAILQ_HEAD(, swdevt) swtailq;
117 struct swdevt *sp, swinfo;
118 struct kvm_swap tot;
119
120 if (!kd->arch->ka_native(kd)) {
121 _kvm_err(kd, kd->program,
122 "cannot read swapinfo from non-native core");
123 return (-1);
124 }
125
126 if (!nlist_init(kd))
127 return (-1);
128
129 bzero(&tot, sizeof(tot));
130 KGET(NL_SWTAILQ, &swtailq);
131 sp = TAILQ_FIRST(&swtailq);
132 for (i = 0; sp != NULL; i++) {
133 KGET2(sp, &swinfo, "swinfo");
134 ttl = swinfo.sw_nblks - dmmax;
135 if (i < swap_max - 1) {
136 bzero(&swap_ary[i], sizeof(swap_ary[i]));
137 swap_ary[i].ksw_total = ttl;
138 swap_ary[i].ksw_used = swinfo.sw_used;
139 swap_ary[i].ksw_flags = swinfo.sw_flags;
140 GETSWDEVNAME(swinfo.sw_dev, swap_ary[i].ksw_devname,
141 flags);
142 }
143 tot.ksw_total += ttl;
144 tot.ksw_used += swinfo.sw_used;
145 sp = TAILQ_NEXT(&swinfo, sw_list);
146 }
147
148 if (i >= swap_max)
149 i = swap_max - 1;
150 if (i >= 0)
151 swap_ary[i] = tot;
152
153 return(i);
154 }
155
156 #define GETSYSCTL(kd, name, var) \
157 getsysctl(kd, name, &(var), sizeof(var))
158
159 /* The maximum MIB length for vm.swap_info and an additional device number */
160 #define SWI_MAXMIB 3
161
162 int
kvm_getswapinfo_sysctl(kvm_t * kd,struct kvm_swap * swap_ary,int swap_max,int flags)163 kvm_getswapinfo_sysctl(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max,
164 int flags)
165 {
166 int ti, ttl;
167 size_t mibi, len;
168 int soid[SWI_MAXMIB];
169 struct xswdev xsd;
170 struct kvm_swap tot;
171
172 if (!GETSYSCTL(kd, "vm.dmmax", dmmax))
173 return -1;
174
175 mibi = SWI_MAXMIB - 1;
176 if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) {
177 _kvm_err(kd, kd->program, "sysctlnametomib failed: %s",
178 strerror(errno));
179 return -1;
180 }
181 bzero(&tot, sizeof(tot));
182 for (unswdev = 0;; unswdev++) {
183 soid[mibi] = unswdev;
184 len = sizeof(xsd);
185 if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) {
186 if (errno == ENOENT)
187 break;
188 _kvm_err(kd, kd->program, "cannot read sysctl: %s.",
189 strerror(errno));
190 return -1;
191 }
192 if (len != sizeof(xsd)) {
193 _kvm_err(kd, kd->program, "struct xswdev has unexpected "
194 "size; kernel and libkvm out of sync?");
195 return -1;
196 }
197 if (xsd.xsw_version != XSWDEV_VERSION) {
198 _kvm_err(kd, kd->program, "struct xswdev version "
199 "mismatch; kernel and libkvm out of sync?");
200 return -1;
201 }
202
203 ttl = xsd.xsw_nblks - dmmax;
204 if (unswdev < swap_max - 1) {
205 bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev]));
206 swap_ary[unswdev].ksw_total = ttl;
207 swap_ary[unswdev].ksw_used = xsd.xsw_used;
208 swap_ary[unswdev].ksw_flags = xsd.xsw_flags;
209 GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname,
210 flags);
211 }
212 tot.ksw_total += ttl;
213 tot.ksw_used += xsd.xsw_used;
214 }
215
216 ti = unswdev;
217 if (ti >= swap_max)
218 ti = swap_max - 1;
219 if (ti >= 0)
220 swap_ary[ti] = tot;
221
222 return(ti);
223 }
224
225 static int
nlist_init(kvm_t * kd)226 nlist_init(kvm_t *kd)
227 {
228
229 if (kvm_swap_nl_cached)
230 return (1);
231
232 if (kvm_nlist(kd, kvm_swap_nl) < 0)
233 return (0);
234
235 /* Required entries */
236 if (kvm_swap_nl[NL_SWTAILQ].n_value == 0) {
237 _kvm_err(kd, kd->program, "unable to find swtailq");
238 return (0);
239 }
240
241 if (kvm_swap_nl[NL_DMMAX].n_value == 0) {
242 _kvm_err(kd, kd->program, "unable to find dmmax");
243 return (0);
244 }
245
246 /* Get globals, type of swap */
247 KGET(NL_DMMAX, &dmmax);
248
249 kvm_swap_nl_cached = 1;
250 return (1);
251 }
252
253 static int
getsysctl(kvm_t * kd,const char * name,void * ptr,size_t len)254 getsysctl(kvm_t *kd, const char *name, void *ptr, size_t len)
255 {
256 size_t nlen = len;
257 if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
258 _kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
259 strerror(errno));
260 return (0);
261 }
262 if (nlen != len) {
263 _kvm_err(kd, kd->program, "sysctl %s has unexpected size", name);
264 return (0);
265 }
266 return (1);
267 }
268