1 /* $OpenBSD: kern_subr.c,v 1.10 1999/11/07 17:39:14 provos Exp $ */ 2 /* $NetBSD: kern_subr.c,v 1.15 1996/04/09 17:21:56 ragge Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/proc.h> 47 #include <sys/malloc.h> 48 #include <sys/queue.h> 49 50 int 51 uiomove(cp, n, uio) 52 register caddr_t cp; 53 register int n; 54 register struct uio *uio; 55 { 56 register struct iovec *iov; 57 u_int cnt; 58 int error = 0; 59 60 #ifdef DIAGNOSTIC 61 if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) 62 panic("uiomove: mode"); 63 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 64 panic("uiomove proc"); 65 #endif 66 while (n > 0 && uio->uio_resid) { 67 iov = uio->uio_iov; 68 cnt = iov->iov_len; 69 if (cnt == 0) { 70 uio->uio_iov++; 71 uio->uio_iovcnt--; 72 continue; 73 } 74 if (cnt > n) 75 cnt = n; 76 switch (uio->uio_segflg) { 77 78 case UIO_USERSPACE: 79 if (uio->uio_rw == UIO_READ) 80 error = copyout(cp, iov->iov_base, cnt); 81 else 82 error = copyin(iov->iov_base, cp, cnt); 83 if (error) 84 return (error); 85 break; 86 87 case UIO_SYSSPACE: 88 #if defined(UVM) 89 if (uio->uio_rw == UIO_READ) 90 error = kcopy(cp, iov->iov_base, cnt); 91 else 92 error = kcopy(iov->iov_base, cp, cnt); 93 if (error) 94 return(error); 95 #else 96 if (uio->uio_rw == UIO_READ) 97 bcopy((caddr_t)cp, iov->iov_base, cnt); 98 else 99 bcopy(iov->iov_base, (caddr_t)cp, cnt); 100 break; 101 #endif 102 } 103 iov->iov_base += cnt; 104 iov->iov_len -= cnt; 105 uio->uio_resid -= cnt; 106 uio->uio_offset += cnt; 107 cp += cnt; 108 n -= cnt; 109 } 110 return (error); 111 } 112 113 /* 114 * Give next character to user as result of read. 115 */ 116 int 117 ureadc(c, uio) 118 register int c; 119 register struct uio *uio; 120 { 121 register struct iovec *iov; 122 123 if (uio->uio_resid == 0) 124 #ifdef DIAGNOSTIC 125 panic("ureadc: zero resid"); 126 #else 127 return (EINVAL); 128 #endif 129 again: 130 if (uio->uio_iovcnt <= 0) 131 #ifdef DIAGNOSTIC 132 panic("ureadc: non-positive iovcnt"); 133 #else 134 return (EINVAL); 135 #endif 136 iov = uio->uio_iov; 137 if (iov->iov_len <= 0) { 138 uio->uio_iovcnt--; 139 uio->uio_iov++; 140 goto again; 141 } 142 switch (uio->uio_segflg) { 143 144 case UIO_USERSPACE: 145 if (subyte(iov->iov_base, c) < 0) 146 return (EFAULT); 147 break; 148 149 case UIO_SYSSPACE: 150 *(char *)iov->iov_base = c; 151 break; 152 } 153 iov->iov_base++; 154 iov->iov_len--; 155 uio->uio_resid--; 156 uio->uio_offset++; 157 return (0); 158 } 159 160 /* 161 * General routine to allocate a hash table. 162 */ 163 void * 164 hashinit(elements, type, flags, hashmask) 165 int elements, type, flags; 166 u_long *hashmask; 167 { 168 long hashsize; 169 LIST_HEAD(generic, generic) *hashtbl; 170 int i; 171 172 if (elements <= 0) 173 panic("hashinit: bad cnt"); 174 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 175 continue; 176 hashsize >>= 1; 177 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, flags); 178 for (i = 0; i < hashsize; i++) 179 LIST_INIT(&hashtbl[i]); 180 *hashmask = hashsize - 1; 181 return (hashtbl); 182 } 183 184 /* 185 * "Shutdown hook" types, functions, and variables. 186 */ 187 188 struct shutdownhook_desc { 189 LIST_ENTRY(shutdownhook_desc) sfd_list; 190 void (*sfd_fn) __P((void *)); 191 void *sfd_arg; 192 }; 193 194 LIST_HEAD(, shutdownhook_desc) shutdownhook_list; 195 196 int shutdownhooks_done; 197 198 void * 199 shutdownhook_establish(fn, arg) 200 void (*fn) __P((void *)); 201 void *arg; 202 { 203 struct shutdownhook_desc *ndp; 204 205 ndp = (struct shutdownhook_desc *) 206 malloc(sizeof (*ndp), M_DEVBUF, M_NOWAIT); 207 if (ndp == NULL) 208 return NULL; 209 210 ndp->sfd_fn = fn; 211 ndp->sfd_arg = arg; 212 LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list); 213 214 return (ndp); 215 } 216 217 void 218 shutdownhook_disestablish(vhook) 219 void *vhook; 220 { 221 #ifdef DIAGNOSTIC 222 struct shutdownhook_desc *dp; 223 224 for (dp = shutdownhook_list.lh_first; dp != NULL; 225 dp = dp->sfd_list.le_next) 226 if (dp == vhook) 227 break; 228 if (dp == NULL) 229 panic("shutdownhook_disestablish: hook not established"); 230 #endif 231 232 LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list); 233 } 234 235 /* 236 * Run shutdown hooks. Should be invoked immediately before the 237 * system is halted or rebooted, i.e. after file systems unmounted, 238 * after crash dump done, etc. 239 */ 240 void 241 doshutdownhooks() 242 { 243 struct shutdownhook_desc *dp; 244 245 if (shutdownhooks_done) 246 return; 247 248 for (dp = shutdownhook_list.lh_first; dp != NULL; dp = 249 dp->sfd_list.le_next) 250 (*dp->sfd_fn)(dp->sfd_arg); 251 } 252 253 /* 254 * "Power hook" types, functions, and variables. 255 */ 256 257 struct powerhook_desc { 258 LIST_ENTRY(powerhook_desc) sfd_list; 259 void (*sfd_fn) __P((int, void *)); 260 void *sfd_arg; 261 }; 262 263 LIST_HEAD(, powerhook_desc) powerhook_list; 264 265 void * 266 powerhook_establish(fn, arg) 267 void (*fn) __P((int, void *)); 268 void *arg; 269 { 270 struct powerhook_desc *ndp; 271 272 ndp = (struct powerhook_desc *) 273 malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT); 274 if (ndp == NULL) 275 return NULL; 276 277 ndp->sfd_fn = fn; 278 ndp->sfd_arg = arg; 279 LIST_INSERT_HEAD(&powerhook_list, ndp, sfd_list); 280 281 return (ndp); 282 } 283 284 void 285 powerhook_disestablish(vhook) 286 void *vhook; 287 { 288 #ifdef DIAGNOSTIC 289 struct powerhook_desc *dp; 290 291 for (dp = powerhook_list.lh_first; dp != NULL; 292 dp = dp->sfd_list.le_next) 293 if (dp == vhook) 294 break; 295 if (dp == NULL) 296 panic("powerhook_disestablish: hook not established"); 297 #endif 298 299 LIST_REMOVE((struct powerhook_desc *)vhook, sfd_list); 300 free(vhook, M_DEVBUF); 301 } 302 303 /* 304 * Run power hooks. 305 */ 306 void 307 dopowerhooks(why) 308 int why; 309 { 310 struct powerhook_desc *dp; 311 312 for (dp = LIST_FIRST(&powerhook_list); 313 dp != NULL; 314 dp = LIST_NEXT(dp, sfd_list)) { 315 (*dp->sfd_fn)(why, dp->sfd_arg); 316 } 317 } 318