1 /* 2 * Copyright (c) 1999, Matthew Dillon. All Rights Reserved. 3 * Copyright (c) 2001, Thomas Moestl. All Rights Reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/time.h> 32 #include <sys/stat.h> 33 #include <sys/blist.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 { "_swtailq" }, /* list of swap devices and sizes */ 55 { "_dmmax" }, /* maximum size of a swap block */ 56 { 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 *, 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 93 kvm_getswapinfo( 94 kvm_t *kd, 95 struct kvm_swap *swap_ary, 96 int swap_max, 97 int flags 98 ) { 99 100 /* 101 * clear cache 102 */ 103 if (kd == NULL) { 104 kvm_swap_nl_cached = 0; 105 return(0); 106 } 107 108 if (ISALIVE(kd)) { 109 return kvm_getswapinfo_sysctl(kd, swap_ary, swap_max, flags); 110 } else { 111 return kvm_getswapinfo_kvm(kd, swap_ary, swap_max, flags); 112 } 113 } 114 115 int 116 kvm_getswapinfo_kvm( 117 kvm_t *kd, 118 struct kvm_swap *swap_ary, 119 int swap_max, 120 int flags 121 ) { 122 int i, ttl; 123 TAILQ_HEAD(, swdevt) swtailq; 124 struct swdevt *sp, swinfo; 125 struct kvm_swap tot; 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( 165 kvm_t *kd, 166 struct kvm_swap *swap_ary, 167 int swap_max, 168 int flags 169 ) { 170 int ti, ttl; 171 size_t mibi, len; 172 int soid[SWI_MAXMIB]; 173 struct xswdev xsd; 174 struct kvm_swap tot; 175 176 if (!GETSYSCTL(kd, "vm.dmmax", dmmax)) 177 return -1; 178 179 mibi = SWI_MAXMIB - 1; 180 if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) { 181 _kvm_err(kd, kd->program, "sysctlnametomib failed: %s", 182 strerror(errno)); 183 return -1; 184 } 185 bzero(&tot, sizeof(tot)); 186 for (unswdev = 0;; unswdev++) { 187 soid[mibi] = unswdev; 188 len = sizeof(xsd); 189 if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) { 190 if (errno == ENOENT) 191 break; 192 _kvm_err(kd, kd->program, "cannot read sysctl: %s.", 193 strerror(errno)); 194 return -1; 195 } 196 if (len != sizeof(xsd)) { 197 _kvm_err(kd, kd->program, "struct xswdev has unexpected " 198 "size; kernel and libkvm out of sync?"); 199 return -1; 200 } 201 if (xsd.xsw_version != XSWDEV_VERSION) { 202 _kvm_err(kd, kd->program, "struct xswdev version " 203 "mismatch; kernel and libkvm out of sync?"); 204 return -1; 205 } 206 207 ttl = xsd.xsw_nblks - dmmax; 208 if (unswdev < swap_max - 1) { 209 bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev])); 210 swap_ary[unswdev].ksw_total = ttl; 211 swap_ary[unswdev].ksw_used = xsd.xsw_used; 212 swap_ary[unswdev].ksw_flags = xsd.xsw_flags; 213 GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname, 214 flags); 215 } 216 tot.ksw_total += ttl; 217 tot.ksw_used += xsd.xsw_used; 218 } 219 220 ti = unswdev; 221 if (ti >= swap_max) 222 ti = swap_max - 1; 223 if (ti >= 0) 224 swap_ary[ti] = tot; 225 226 return(ti); 227 } 228 229 static int 230 nlist_init(kvm_t *kd) 231 { 232 TAILQ_HEAD(, swdevt) swtailq; 233 struct swdevt *sp, swinfo; 234 235 if (kvm_swap_nl_cached) 236 return (1); 237 238 if (kvm_nlist(kd, kvm_swap_nl) < 0) 239 return (0); 240 241 /* Required entries */ 242 if (kvm_swap_nl[NL_SWTAILQ].n_value == 0) { 243 _kvm_err(kd, kd->program, "unable to find swtailq"); 244 return (0); 245 } 246 247 if (kvm_swap_nl[NL_DMMAX].n_value == 0) { 248 _kvm_err(kd, kd->program, "unable to find dmmax"); 249 return (0); 250 } 251 252 /* Get globals, type of swap */ 253 KGET(NL_DMMAX, &dmmax); 254 255 kvm_swap_nl_cached = 1; 256 return (1); 257 } 258 259 static int 260 getsysctl ( 261 kvm_t *kd, 262 char *name, 263 void *ptr, 264 size_t len 265 ) { 266 size_t nlen = len; 267 if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) { 268 _kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name, 269 strerror(errno)); 270 return (0); 271 } 272 if (nlen != len) { 273 _kvm_err(kd, kd->program, "sysctl %s has unexpected size", name); 274 return (0); 275 } 276 return (1); 277 } 278