1 /* 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * %sccs.include.redist.c% 11 * 12 * @(#)kern_subr.c 8.3 (Berkeley) 01/21/94 13 */ 14 15 #include <sys/param.h> 16 #include <sys/systm.h> 17 #include <sys/proc.h> 18 #include <sys/malloc.h> 19 #include <sys/queue.h> 20 21 uiomove(cp, n, uio) 22 register caddr_t cp; 23 register int n; 24 register struct uio *uio; 25 { 26 register struct iovec *iov; 27 u_int cnt; 28 int error = 0; 29 30 #ifdef DIAGNOSTIC 31 if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) 32 panic("uiomove: mode"); 33 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 34 panic("uiomove proc"); 35 #endif 36 while (n > 0 && uio->uio_resid) { 37 iov = uio->uio_iov; 38 cnt = iov->iov_len; 39 if (cnt == 0) { 40 uio->uio_iov++; 41 uio->uio_iovcnt--; 42 continue; 43 } 44 if (cnt > n) 45 cnt = n; 46 switch (uio->uio_segflg) { 47 48 case UIO_USERSPACE: 49 case UIO_USERISPACE: 50 if (uio->uio_rw == UIO_READ) 51 error = copyout(cp, iov->iov_base, cnt); 52 else 53 error = copyin(iov->iov_base, cp, cnt); 54 if (error) 55 return (error); 56 break; 57 58 case UIO_SYSSPACE: 59 if (uio->uio_rw == UIO_READ) 60 bcopy((caddr_t)cp, iov->iov_base, cnt); 61 else 62 bcopy(iov->iov_base, (caddr_t)cp, cnt); 63 break; 64 } 65 iov->iov_base += cnt; 66 iov->iov_len -= cnt; 67 uio->uio_resid -= cnt; 68 uio->uio_offset += cnt; 69 cp += cnt; 70 n -= cnt; 71 } 72 return (error); 73 } 74 75 /* 76 * Give next character to user as result of read. 77 */ 78 ureadc(c, uio) 79 register int c; 80 register struct uio *uio; 81 { 82 register struct iovec *iov; 83 84 again: 85 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 86 panic("ureadc"); 87 iov = uio->uio_iov; 88 if (iov->iov_len == 0) { 89 uio->uio_iovcnt--; 90 uio->uio_iov++; 91 goto again; 92 } 93 switch (uio->uio_segflg) { 94 95 case UIO_USERSPACE: 96 if (subyte(iov->iov_base, c) < 0) 97 return (EFAULT); 98 break; 99 100 case UIO_SYSSPACE: 101 *iov->iov_base = c; 102 break; 103 104 case UIO_USERISPACE: 105 if (suibyte(iov->iov_base, c) < 0) 106 return (EFAULT); 107 break; 108 } 109 iov->iov_base++; 110 iov->iov_len--; 111 uio->uio_resid--; 112 uio->uio_offset++; 113 return (0); 114 } 115 116 #ifdef vax /* unused except by ct.c, other oddities XXX */ 117 /* 118 * Get next character written in by user from uio. 119 */ 120 uwritec(uio) 121 struct uio *uio; 122 { 123 register struct iovec *iov; 124 register int c; 125 126 if (uio->uio_resid <= 0) 127 return (-1); 128 again: 129 if (uio->uio_iovcnt <= 0) 130 panic("uwritec"); 131 iov = uio->uio_iov; 132 if (iov->iov_len == 0) { 133 uio->uio_iov++; 134 if (--uio->uio_iovcnt == 0) 135 return (-1); 136 goto again; 137 } 138 switch (uio->uio_segflg) { 139 140 case UIO_USERSPACE: 141 c = fubyte(iov->iov_base); 142 break; 143 144 case UIO_SYSSPACE: 145 c = *(u_char *) iov->iov_base; 146 break; 147 148 case UIO_USERISPACE: 149 c = fuibyte(iov->iov_base); 150 break; 151 } 152 if (c < 0) 153 return (-1); 154 iov->iov_base++; 155 iov->iov_len--; 156 uio->uio_resid--; 157 uio->uio_offset++; 158 return (c); 159 } 160 #endif /* vax */ 161 162 /* 163 * General routine to allocate a hash table. 164 */ 165 void * 166 hashinit(elements, type, hashmask) 167 int elements, type; 168 u_long *hashmask; 169 { 170 long hashsize; 171 LIST_HEAD(generic, generic) *hashtbl; 172 int i; 173 174 if (elements <= 0) 175 panic("hashinit: bad cnt"); 176 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 177 continue; 178 hashsize >>= 1; 179 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); 180 for (i = 0; i < hashsize; i++) 181 LIST_INIT(&hashtbl[i]); 182 *hashmask = hashsize - 1; 183 return (hashtbl); 184 } 185