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 8.4 (Berkeley) 02/14/95 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 int 22 uiomove(cp, n, uio) 23 register caddr_t cp; 24 register int n; 25 register struct uio *uio; 26 { 27 register struct iovec *iov; 28 u_int cnt; 29 int error = 0; 30 31 #ifdef DIAGNOSTIC 32 if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) 33 panic("uiomove: mode"); 34 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 35 panic("uiomove proc"); 36 #endif 37 while (n > 0 && uio->uio_resid) { 38 iov = uio->uio_iov; 39 cnt = iov->iov_len; 40 if (cnt == 0) { 41 uio->uio_iov++; 42 uio->uio_iovcnt--; 43 continue; 44 } 45 if (cnt > n) 46 cnt = n; 47 switch (uio->uio_segflg) { 48 49 case UIO_USERSPACE: 50 case UIO_USERISPACE: 51 if (uio->uio_rw == UIO_READ) 52 error = copyout(cp, iov->iov_base, cnt); 53 else 54 error = copyin(iov->iov_base, cp, cnt); 55 if (error) 56 return (error); 57 break; 58 59 case UIO_SYSSPACE: 60 if (uio->uio_rw == UIO_READ) 61 bcopy((caddr_t)cp, iov->iov_base, cnt); 62 else 63 bcopy(iov->iov_base, (caddr_t)cp, cnt); 64 break; 65 } 66 iov->iov_base += cnt; 67 iov->iov_len -= cnt; 68 uio->uio_resid -= cnt; 69 uio->uio_offset += cnt; 70 cp += cnt; 71 n -= cnt; 72 } 73 return (error); 74 } 75 76 /* 77 * Give next character to user as result of read. 78 */ 79 int 80 ureadc(c, uio) 81 register int c; 82 register struct uio *uio; 83 { 84 register struct iovec *iov; 85 86 if (uio->uio_resid <= 0) 87 panic("ureadc: non-positive resid"); 88 again: 89 if (uio->uio_iovcnt <= 0) 90 panic("ureadc: non-positive iovcnt"); 91 iov = uio->uio_iov; 92 if (iov->iov_len <= 0) { 93 uio->uio_iovcnt--; 94 uio->uio_iov++; 95 goto again; 96 } 97 switch (uio->uio_segflg) { 98 99 case UIO_USERSPACE: 100 if (subyte(iov->iov_base, c) < 0) 101 return (EFAULT); 102 break; 103 104 case UIO_SYSSPACE: 105 *iov->iov_base = c; 106 break; 107 108 case UIO_USERISPACE: 109 if (suibyte(iov->iov_base, c) < 0) 110 return (EFAULT); 111 break; 112 } 113 iov->iov_base++; 114 iov->iov_len--; 115 uio->uio_resid--; 116 uio->uio_offset++; 117 return (0); 118 } 119 120 #ifdef vax /* unused except by ct.c, other oddities XXX */ 121 /* 122 * Get next character written in by user from uio. 123 */ 124 int 125 uwritec(uio) 126 struct uio *uio; 127 { 128 register struct iovec *iov; 129 register int c; 130 131 if (uio->uio_resid <= 0) 132 return (-1); 133 again: 134 if (uio->uio_iovcnt <= 0) 135 panic("uwritec: non-positive iovcnt"); 136 iov = uio->uio_iov; 137 if (iov->iov_len == 0) { 138 uio->uio_iov++; 139 if (--uio->uio_iovcnt == 0) 140 return (-1); 141 goto again; 142 } 143 switch (uio->uio_segflg) { 144 145 case UIO_USERSPACE: 146 c = fubyte(iov->iov_base); 147 break; 148 149 case UIO_SYSSPACE: 150 c = *(u_char *) iov->iov_base; 151 break; 152 153 case UIO_USERISPACE: 154 c = fuibyte(iov->iov_base); 155 break; 156 } 157 if (c < 0) 158 return (-1); 159 iov->iov_base++; 160 iov->iov_len--; 161 uio->uio_resid--; 162 uio->uio_offset++; 163 return (c); 164 } 165 #endif /* vax */ 166 167 /* 168 * General routine to allocate a hash table. 169 */ 170 void * 171 hashinit(elements, type, hashmask) 172 int elements, type; 173 u_long *hashmask; 174 { 175 long hashsize; 176 LIST_HEAD(generic, generic) *hashtbl; 177 int i; 178 179 if (elements <= 0) 180 panic("hashinit: bad cnt"); 181 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 182 continue; 183 hashsize >>= 1; 184 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); 185 for (i = 0; i < hashsize; i++) 186 LIST_INIT(&hashtbl[i]); 187 *hashmask = hashsize - 1; 188 return (hashtbl); 189 } 190