1 /* $OpenBSD: kern_subr.c,v 1.8 1999/02/26 04:56:02 art 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, hashmask) 165 int elements, type; 166 u_long *hashmask; 167 { 168 return newhashinit(elements, type, M_WAITOK, hashmask); 169 } 170 171 void * 172 newhashinit(elements, type, flags, hashmask) 173 int elements, type, flags; 174 u_long *hashmask; 175 { 176 long hashsize; 177 LIST_HEAD(generic, generic) *hashtbl; 178 int i; 179 180 if (elements <= 0) 181 panic("hashinit: bad cnt"); 182 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 183 continue; 184 hashsize >>= 1; 185 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, flags); 186 for (i = 0; i < hashsize; i++) 187 LIST_INIT(&hashtbl[i]); 188 *hashmask = hashsize - 1; 189 return (hashtbl); 190 } 191 192 /* 193 * "Shutdown hook" types, functions, and variables. 194 */ 195 196 struct shutdownhook_desc { 197 LIST_ENTRY(shutdownhook_desc) sfd_list; 198 void (*sfd_fn) __P((void *)); 199 void *sfd_arg; 200 }; 201 202 LIST_HEAD(, shutdownhook_desc) shutdownhook_list; 203 204 int shutdownhooks_done; 205 206 void * 207 shutdownhook_establish(fn, arg) 208 void (*fn) __P((void *)); 209 void *arg; 210 { 211 struct shutdownhook_desc *ndp; 212 213 ndp = (struct shutdownhook_desc *) 214 malloc(sizeof (*ndp), M_DEVBUF, M_NOWAIT); 215 if (ndp == NULL) 216 return NULL; 217 218 ndp->sfd_fn = fn; 219 ndp->sfd_arg = arg; 220 LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list); 221 222 return (ndp); 223 } 224 225 void 226 shutdownhook_disestablish(vhook) 227 void *vhook; 228 { 229 #ifdef DIAGNOSTIC 230 struct shutdownhook_desc *dp; 231 232 for (dp = shutdownhook_list.lh_first; dp != NULL; 233 dp = dp->sfd_list.le_next) 234 if (dp == vhook) 235 break; 236 if (dp == NULL) 237 panic("shutdownhook_disestablish: hook not established"); 238 #endif 239 240 LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list); 241 } 242 243 /* 244 * Run shutdown hooks. Should be invoked immediately before the 245 * system is halted or rebooted, i.e. after file systems unmounted, 246 * after crash dump done, etc. 247 */ 248 void 249 doshutdownhooks() 250 { 251 struct shutdownhook_desc *dp; 252 253 if (shutdownhooks_done) 254 return; 255 256 for (dp = shutdownhook_list.lh_first; dp != NULL; dp = 257 dp->sfd_list.le_next) 258 (*dp->sfd_fn)(dp->sfd_arg); 259 } 260