1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/time.h> 34 #include <sys/stat.h> 35 #include <sys/blist.h> 36 #include <sys/queue.h> 37 #include <sys/sysctl.h> 38 39 #include <vm/swap_pager.h> 40 #include <vm/vm_param.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <kvm.h> 46 #include <nlist.h> 47 #include <paths.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <limits.h> 53 54 #include "kvm_private.h" 55 56 static struct nlist kvm_swap_nl[] = { 57 { .n_name = "_swtailq" }, /* list of swap devices and sizes */ 58 { .n_name = "_dmmax" }, /* maximum size of a swap block */ 59 { .n_name = NULL } 60 }; 61 62 #define NL_SWTAILQ 0 63 #define NL_DMMAX 1 64 65 static int kvm_swap_nl_cached = 0; 66 static int unswdev; /* number of found swap dev's */ 67 static int dmmax; 68 69 static int kvm_getswapinfo_kvm(kvm_t *, struct kvm_swap *, int, int); 70 static int kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int); 71 static int nlist_init(kvm_t *); 72 static int getsysctl(kvm_t *, const char *, void *, size_t); 73 74 #define KREAD(kd, addr, obj) \ 75 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 76 #define KGET(idx, var) \ 77 KGET2(kvm_swap_nl[(idx)].n_value, var, kvm_swap_nl[(idx)].n_name) 78 #define KGET2(addr, var, msg) \ 79 if (KREAD(kd, (u_long)(addr), (var))) { \ 80 _kvm_err(kd, kd->program, "cannot read %s", msg); \ 81 return (-1); \ 82 } 83 84 #define GETSWDEVNAME(dev, str, flags) \ 85 if (dev == NODEV) { \ 86 strlcpy(str, "[NFS swap]", sizeof(str)); \ 87 } else { \ 88 snprintf( \ 89 str, sizeof(str),"%s%s", \ 90 ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""), \ 91 devname(dev, S_IFCHR) \ 92 ); \ 93 } 94 95 int 96 kvm_getswapinfo(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags) 97 { 98 99 /* 100 * clear cache 101 */ 102 if (kd == NULL) { 103 kvm_swap_nl_cached = 0; 104 return(0); 105 } 106 107 if (ISALIVE(kd)) { 108 return kvm_getswapinfo_sysctl(kd, swap_ary, swap_max, flags); 109 } else { 110 return kvm_getswapinfo_kvm(kd, swap_ary, swap_max, flags); 111 } 112 } 113 114 int 115 kvm_getswapinfo_kvm(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, 116 int flags) 117 { 118 int i; 119 swblk_t ttl; 120 TAILQ_HEAD(, swdevt) swtailq; 121 struct swdevt *sp, swinfo; 122 struct kvm_swap tot; 123 124 if (!kd->arch->ka_native(kd)) { 125 _kvm_err(kd, kd->program, 126 "cannot read swapinfo from non-native core"); 127 return (-1); 128 } 129 130 if (!nlist_init(kd)) 131 return (-1); 132 133 bzero(&tot, sizeof(tot)); 134 KGET(NL_SWTAILQ, &swtailq); 135 sp = TAILQ_FIRST(&swtailq); 136 for (i = 0; sp != NULL; i++) { 137 KGET2(sp, &swinfo, "swinfo"); 138 ttl = swinfo.sw_nblks - dmmax; 139 if (i < swap_max - 1) { 140 bzero(&swap_ary[i], sizeof(swap_ary[i])); 141 swap_ary[i].ksw_total = ttl; 142 swap_ary[i].ksw_used = swinfo.sw_used; 143 swap_ary[i].ksw_flags = swinfo.sw_flags; 144 GETSWDEVNAME(swinfo.sw_dev, swap_ary[i].ksw_devname, 145 flags); 146 } 147 tot.ksw_total += ttl; 148 tot.ksw_used += swinfo.sw_used; 149 sp = TAILQ_NEXT(&swinfo, sw_list); 150 } 151 152 if (i >= swap_max) 153 i = swap_max - 1; 154 if (i >= 0) 155 swap_ary[i] = tot; 156 157 return(i); 158 } 159 160 #define GETSYSCTL(kd, name, var) \ 161 getsysctl(kd, name, &(var), sizeof(var)) 162 163 /* The maximum MIB length for vm.swap_info and an additional device number */ 164 #define SWI_MAXMIB 3 165 166 int 167 kvm_getswapinfo_sysctl(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, 168 int flags) 169 { 170 int ti; 171 swblk_t ttl; 172 size_t mibi, len; 173 int soid[SWI_MAXMIB]; 174 struct xswdev xsd; 175 struct kvm_swap tot; 176 177 if (!GETSYSCTL(kd, "vm.dmmax", dmmax)) 178 return -1; 179 180 mibi = SWI_MAXMIB - 1; 181 if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) { 182 _kvm_err(kd, kd->program, "sysctlnametomib failed: %s", 183 strerror(errno)); 184 return -1; 185 } 186 bzero(&tot, sizeof(tot)); 187 for (unswdev = 0;; unswdev++) { 188 soid[mibi] = unswdev; 189 len = sizeof(xsd); 190 if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) { 191 if (errno == ENOENT) 192 break; 193 _kvm_err(kd, kd->program, "cannot read sysctl: %s.", 194 strerror(errno)); 195 return -1; 196 } 197 if (len != sizeof(xsd)) { 198 _kvm_err(kd, kd->program, "struct xswdev has unexpected " 199 "size; kernel and libkvm out of sync?"); 200 return -1; 201 } 202 if (xsd.xsw_version != XSWDEV_VERSION) { 203 _kvm_err(kd, kd->program, "struct xswdev version " 204 "mismatch; kernel and libkvm out of sync?"); 205 return -1; 206 } 207 208 ttl = xsd.xsw_nblks - dmmax; 209 if (unswdev < swap_max - 1) { 210 bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev])); 211 swap_ary[unswdev].ksw_total = ttl; 212 swap_ary[unswdev].ksw_used = xsd.xsw_used; 213 swap_ary[unswdev].ksw_flags = xsd.xsw_flags; 214 GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname, 215 flags); 216 } 217 tot.ksw_total += ttl; 218 tot.ksw_used += xsd.xsw_used; 219 } 220 221 ti = unswdev; 222 if (ti >= swap_max) 223 ti = swap_max - 1; 224 if (ti >= 0) 225 swap_ary[ti] = tot; 226 227 return(ti); 228 } 229 230 static int 231 nlist_init(kvm_t *kd) 232 { 233 234 if (kvm_swap_nl_cached) 235 return (1); 236 237 if (kvm_nlist(kd, kvm_swap_nl) < 0) 238 return (0); 239 240 /* Required entries */ 241 if (kvm_swap_nl[NL_SWTAILQ].n_value == 0) { 242 _kvm_err(kd, kd->program, "unable to find swtailq"); 243 return (0); 244 } 245 246 if (kvm_swap_nl[NL_DMMAX].n_value == 0) { 247 _kvm_err(kd, kd->program, "unable to find dmmax"); 248 return (0); 249 } 250 251 /* Get globals, type of swap */ 252 KGET(NL_DMMAX, &dmmax); 253 254 kvm_swap_nl_cached = 1; 255 return (1); 256 } 257 258 static int 259 getsysctl(kvm_t *kd, const char *name, void *ptr, size_t len) 260 { 261 size_t nlen = len; 262 if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) { 263 _kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name, 264 strerror(errno)); 265 return (0); 266 } 267 if (nlen != len) { 268 _kvm_err(kd, kd->program, "sysctl %s has unexpected size", name); 269 return (0); 270 } 271 return (1); 272 } 273