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