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/cdefs.h> 30 #include <sys/param.h> 31 #include <sys/time.h> 32 #include <sys/stat.h> 33 #include <sys/blist.h> 34 #include <sys/queue.h> 35 #include <sys/sysctl.h> 36 37 #include <vm/swap_pager.h> 38 #include <vm/vm_param.h> 39 40 #include <err.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <kvm.h> 44 #include <nlist.h> 45 #include <paths.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include <limits.h> 51 52 #include "kvm_private.h" 53 54 static struct nlist kvm_swap_nl[] = { 55 { .n_name = "_swtailq" }, /* list of swap devices and sizes */ 56 { .n_name = "_dmmax" }, /* maximum size of a swap block */ 57 { .n_name = NULL } 58 }; 59 60 #define NL_SWTAILQ 0 61 #define NL_DMMAX 1 62 63 static int kvm_swap_nl_cached = 0; 64 static int unswdev; /* number of found swap dev's */ 65 static int dmmax; 66 67 static int kvm_getswapinfo_kvm(kvm_t *, struct kvm_swap *, int, int); 68 static int kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int); 69 static int nlist_init(kvm_t *); 70 static int getsysctl(kvm_t *, const char *, void *, size_t); 71 72 #define KREAD(kd, addr, obj) \ 73 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 74 #define KGET(idx, var) \ 75 KGET2(kvm_swap_nl[(idx)].n_value, var, kvm_swap_nl[(idx)].n_name) 76 #define KGET2(addr, var, msg) \ 77 if (KREAD(kd, (u_long)(addr), (var))) { \ 78 _kvm_err(kd, kd->program, "cannot read %s", msg); \ 79 return (-1); \ 80 } 81 82 #define GETSWDEVNAME(dev, str, flags) \ 83 if (dev == NODEV) { \ 84 strlcpy(str, "[NFS swap]", sizeof(str)); \ 85 } else { \ 86 snprintf( \ 87 str, sizeof(str),"%s%s", \ 88 ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""), \ 89 devname(dev, S_IFCHR) \ 90 ); \ 91 } 92 93 int 94 kvm_getswapinfo(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags) 95 { 96 97 /* 98 * clear cache 99 */ 100 if (kd == NULL) { 101 kvm_swap_nl_cached = 0; 102 return(0); 103 } 104 105 if (ISALIVE(kd)) { 106 return kvm_getswapinfo_sysctl(kd, swap_ary, swap_max, flags); 107 } else { 108 return kvm_getswapinfo_kvm(kd, swap_ary, swap_max, flags); 109 } 110 } 111 112 int 113 kvm_getswapinfo_kvm(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, 114 int flags) 115 { 116 int i, ttl; 117 TAILQ_HEAD(, swdevt) swtailq; 118 struct swdevt *sp, swinfo; 119 struct kvm_swap tot; 120 121 if (!kd->arch->ka_native(kd)) { 122 _kvm_err(kd, kd->program, 123 "cannot read swapinfo from non-native core"); 124 return (-1); 125 } 126 127 if (!nlist_init(kd)) 128 return (-1); 129 130 bzero(&tot, sizeof(tot)); 131 KGET(NL_SWTAILQ, &swtailq); 132 sp = TAILQ_FIRST(&swtailq); 133 for (i = 0; sp != NULL; i++) { 134 KGET2(sp, &swinfo, "swinfo"); 135 ttl = swinfo.sw_nblks - dmmax; 136 if (i < swap_max - 1) { 137 bzero(&swap_ary[i], sizeof(swap_ary[i])); 138 swap_ary[i].ksw_total = ttl; 139 swap_ary[i].ksw_used = swinfo.sw_used; 140 swap_ary[i].ksw_flags = swinfo.sw_flags; 141 GETSWDEVNAME(swinfo.sw_dev, swap_ary[i].ksw_devname, 142 flags); 143 } 144 tot.ksw_total += ttl; 145 tot.ksw_used += swinfo.sw_used; 146 sp = TAILQ_NEXT(&swinfo, sw_list); 147 } 148 149 if (i >= swap_max) 150 i = swap_max - 1; 151 if (i >= 0) 152 swap_ary[i] = tot; 153 154 return(i); 155 } 156 157 #define GETSYSCTL(kd, name, var) \ 158 getsysctl(kd, name, &(var), sizeof(var)) 159 160 /* The maximum MIB length for vm.swap_info and an additional device number */ 161 #define SWI_MAXMIB 3 162 163 int 164 kvm_getswapinfo_sysctl(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, 165 int flags) 166 { 167 int ti, ttl; 168 size_t mibi, len; 169 int soid[SWI_MAXMIB]; 170 struct xswdev xsd; 171 struct kvm_swap tot; 172 173 if (!GETSYSCTL(kd, "vm.dmmax", dmmax)) 174 return -1; 175 176 mibi = SWI_MAXMIB - 1; 177 if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) { 178 _kvm_err(kd, kd->program, "sysctlnametomib failed: %s", 179 strerror(errno)); 180 return -1; 181 } 182 bzero(&tot, sizeof(tot)); 183 for (unswdev = 0;; unswdev++) { 184 soid[mibi] = unswdev; 185 len = sizeof(xsd); 186 if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) { 187 if (errno == ENOENT) 188 break; 189 _kvm_err(kd, kd->program, "cannot read sysctl: %s.", 190 strerror(errno)); 191 return -1; 192 } 193 if (len != sizeof(xsd)) { 194 _kvm_err(kd, kd->program, "struct xswdev has unexpected " 195 "size; kernel and libkvm out of sync?"); 196 return -1; 197 } 198 if (xsd.xsw_version != XSWDEV_VERSION) { 199 _kvm_err(kd, kd->program, "struct xswdev version " 200 "mismatch; kernel and libkvm out of sync?"); 201 return -1; 202 } 203 204 ttl = xsd.xsw_nblks - dmmax; 205 if (unswdev < swap_max - 1) { 206 bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev])); 207 swap_ary[unswdev].ksw_total = ttl; 208 swap_ary[unswdev].ksw_used = xsd.xsw_used; 209 swap_ary[unswdev].ksw_flags = xsd.xsw_flags; 210 GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname, 211 flags); 212 } 213 tot.ksw_total += ttl; 214 tot.ksw_used += xsd.xsw_used; 215 } 216 217 ti = unswdev; 218 if (ti >= swap_max) 219 ti = swap_max - 1; 220 if (ti >= 0) 221 swap_ary[ti] = tot; 222 223 return(ti); 224 } 225 226 static int 227 nlist_init(kvm_t *kd) 228 { 229 230 if (kvm_swap_nl_cached) 231 return (1); 232 233 if (kvm_nlist(kd, kvm_swap_nl) < 0) 234 return (0); 235 236 /* Required entries */ 237 if (kvm_swap_nl[NL_SWTAILQ].n_value == 0) { 238 _kvm_err(kd, kd->program, "unable to find swtailq"); 239 return (0); 240 } 241 242 if (kvm_swap_nl[NL_DMMAX].n_value == 0) { 243 _kvm_err(kd, kd->program, "unable to find dmmax"); 244 return (0); 245 } 246 247 /* Get globals, type of swap */ 248 KGET(NL_DMMAX, &dmmax); 249 250 kvm_swap_nl_cached = 1; 251 return (1); 252 } 253 254 static int 255 getsysctl(kvm_t *kd, const char *name, void *ptr, size_t len) 256 { 257 size_t nlen = len; 258 if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) { 259 _kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name, 260 strerror(errno)); 261 return (0); 262 } 263 if (nlen != len) { 264 _kvm_err(kd, kd->program, "sysctl %s has unexpected size", name); 265 return (0); 266 } 267 return (1); 268 } 269