kern_subr.c revision 1.14
1 /* $NetBSD: kern_subr.c,v 1.14 1995/05/31 20:41:44 cgd 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 #ifdef vax /* unused except by ct.c, other oddities XXX */ 143 /* 144 * Get next character written in by user from uio. 145 */ 146 int 147 uwritec(uio) 148 struct uio *uio; 149 { 150 register struct iovec *iov; 151 register int c; 152 153 if (uio->uio_resid <= 0) 154 return (-1); 155 again: 156 if (uio->uio_iovcnt <= 0) 157 panic("ureadc: non-positive iovcnt"); 158 iov = uio->uio_iov; 159 if (iov->iov_len == 0) { 160 uio->uio_iov++; 161 if (--uio->uio_iovcnt == 0) 162 return (-1); 163 goto again; 164 } 165 switch (uio->uio_segflg) { 166 167 case UIO_USERSPACE: 168 c = fubyte(iov->iov_base); 169 break; 170 171 case UIO_SYSSPACE: 172 c = *(u_char *) iov->iov_base; 173 break; 174 } 175 if (c < 0) 176 return (-1); 177 iov->iov_base++; 178 iov->iov_len--; 179 uio->uio_resid--; 180 uio->uio_offset++; 181 return (c); 182 } 183 #endif /* vax */ 184 185 /* 186 * General routine to allocate a hash table. 187 */ 188 void * 189 hashinit(elements, type, hashmask) 190 int elements, type; 191 u_long *hashmask; 192 { 193 long hashsize; 194 LIST_HEAD(generic, generic) *hashtbl; 195 int i; 196 197 if (elements <= 0) 198 panic("hashinit: bad cnt"); 199 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 200 continue; 201 hashsize >>= 1; 202 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); 203 for (i = 0; i < hashsize; i++) 204 LIST_INIT(&hashtbl[i]); 205 *hashmask = hashsize - 1; 206 return (hashtbl); 207 } 208 209 /* 210 * "Shutdown hook" types, functions, and variables. 211 */ 212 213 struct shutdownhook_desc { 214 LIST_ENTRY(shutdownhook_desc) sfd_list; 215 void (*sfd_fn) __P((void *)); 216 void *sfd_arg; 217 }; 218 219 LIST_HEAD(, shutdownhook_desc) shutdownhook_list; 220 221 int shutdownhooks_done; 222 223 void * 224 shutdownhook_establish(fn, arg) 225 void (*fn) __P((void *)); 226 void *arg; 227 { 228 struct shutdownhook_desc *ndp; 229 230 ndp = (struct shutdownhook_desc *) 231 malloc(sizeof (*ndp), M_DEVBUF, M_NOWAIT); 232 if (ndp == NULL) 233 return NULL; 234 235 ndp->sfd_fn = fn; 236 ndp->sfd_arg = arg; 237 LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list); 238 239 return (ndp); 240 } 241 242 void 243 shutdownhook_disestablish(vhook) 244 void *vhook; 245 { 246 #ifdef DIAGNOSTIC 247 struct shutdownhook_desc *dp; 248 249 for (dp = shutdownhook_list.lh_first; dp != NULL; 250 dp = dp->sfd_list.le_next) 251 if (dp == vhook) 252 break; 253 if (dp == NULL) 254 panic("shutdownhook_disestablish: hook not established"); 255 #endif 256 257 LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list); 258 } 259 260 /* 261 * Run shutdown hooks. Should be invoked immediately before the 262 * system is halted or rebooted, i.e. after file systems unmounted, 263 * after crash dump done, etc. 264 */ 265 void 266 doshutdownhooks() 267 { 268 struct shutdownhook_desc *dp; 269 270 if (shutdownhooks_done) 271 return; 272 273 for (dp = shutdownhook_list.lh_first; dp != NULL; dp = 274 dp->sfd_list.le_next) 275 (*dp->sfd_fn)(dp->sfd_arg); 276 } 277
Indexes created Tue Sep 23 14:10:03 GMT 2025