/* $OpenBSD: kern_subr.c,v 1.5 1998/05/11 05:41:59 deraadt Exp $ */ /* $NetBSD: kern_subr.c,v 1.15 1996/04/09 17:21:56 ragge Exp $ */ /* * Copyright (c) 1982, 1986, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/malloc.h> #include <sys/queue.h> int uiomove(cp, n, uio) register caddr_t cp; register int n; register struct uio *uio; { register struct iovec *iov; u_int cnt; int error = 0; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) panic("uiomove: mode"); if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) panic("uiomove proc"); #endif while (n > 0 && uio->uio_resid) { iov = uio->uio_iov; cnt = iov->iov_len; if (cnt == 0) { uio->uio_iov++; uio->uio_iovcnt--; continue; } if (cnt > n) cnt = n; switch (uio->uio_segflg) { case UIO_USERSPACE: if (uio->uio_rw == UIO_READ) error = copyout(cp, iov->iov_base, cnt); else error = copyin(iov->iov_base, cp, cnt); if (error) return (error); break; case UIO_SYSSPACE: if (uio->uio_rw == UIO_READ) bcopy((caddr_t)cp, iov->iov_base, cnt); else bcopy(iov->iov_base, (caddr_t)cp, cnt); break; } iov->iov_base += cnt; iov->iov_len -= cnt; uio->uio_resid -= cnt; uio->uio_offset += cnt; cp += cnt; n -= cnt; } return (error); } /* * Give next character to user as result of read. */ int ureadc(c, uio) register int c; register struct uio *uio; { register struct iovec *iov; if (uio->uio_resid <= 0) panic("ureadc: non-positive resid"); again: if (uio->uio_iovcnt <= 0) panic("ureadc: non-positive iovcnt"); iov = uio->uio_iov; if (iov->iov_len <= 0) { uio->uio_iovcnt--; uio->uio_iov++; goto again; } switch (uio->uio_segflg) { case UIO_USERSPACE: if (subyte(iov->iov_base, c) < 0) return (EFAULT); break; case UIO_SYSSPACE: *(char *)iov->iov_base = c; break; } iov->iov_base++; iov->iov_len--; uio->uio_resid--; uio->uio_offset++; return (0); } /* * General routine to allocate a hash table. */ void * hashinit(elements, type, hashmask) int elements, type; u_long *hashmask; { long hashsize; LIST_HEAD(generic, generic) *hashtbl; int i; if (elements <= 0) panic("hashinit: bad cnt"); for (hashsize = 1; hashsize <= elements; hashsize <<= 1) continue; hashsize >>= 1; hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); for (i = 0; i < hashsize; i++) LIST_INIT(&hashtbl[i]); *hashmask = hashsize - 1; return (hashtbl); } /* * "Shutdown hook" types, functions, and variables. */ struct shutdownhook_desc { LIST_ENTRY(shutdownhook_desc) sfd_list; void (*sfd_fn) __P((void *)); void *sfd_arg; }; LIST_HEAD(, shutdownhook_desc) shutdownhook_list; int shutdownhooks_done; void * shutdownhook_establish(fn, arg) void (*fn) __P((void *)); void *arg; { struct shutdownhook_desc *ndp; ndp = (struct shutdownhook_desc *) malloc(sizeof (*ndp), M_DEVBUF, M_NOWAIT); if (ndp == NULL) return NULL; ndp->sfd_fn = fn; ndp->sfd_arg = arg; LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list); return (ndp); } void shutdownhook_disestablish(vhook) void *vhook; { #ifdef DIAGNOSTIC struct shutdownhook_desc *dp; for (dp = shutdownhook_list.lh_first; dp != NULL; dp = dp->sfd_list.le_next) if (dp == vhook) break; if (dp == NULL) panic("shutdownhook_disestablish: hook not established"); #endif LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list); } /* * Run shutdown hooks. Should be invoked immediately before the * system is halted or rebooted, i.e. after file systems unmounted, * after crash dump done, etc. */ void doshutdownhooks() { struct shutdownhook_desc *dp; if (shutdownhooks_done) return; for (dp = shutdownhook_list.lh_first; dp != NULL; dp = dp->sfd_list.le_next) (*dp->sfd_fn)(dp->sfd_arg); }