/* $OpenBSD: kern_subr.c,v 1.34 2010/09/07 16:21:47 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. 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 #include #include #include #include #include #include #include int uiomove(void *cp, int n, struct uio *uio) { struct iovec *iov; u_int cnt; int error = 0; struct proc *p; p = uio->uio_procp; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) panic("uiomove: mode"); if (uio->uio_segflg == UIO_USERSPACE && p != 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 (curcpu()->ci_schedstate.spc_schedflags & SPCF_SHOULDYIELD) preempt(NULL); 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) error = kcopy(cp, iov->iov_base, cnt); else error = kcopy(iov->iov_base, cp, cnt); if (error) return(error); } iov->iov_base = (caddr_t)iov->iov_base + cnt; iov->iov_len -= cnt; uio->uio_resid -= cnt; uio->uio_offset += cnt; cp = (caddr_t)cp + cnt; n -= cnt; } return (error); } /* * Give next character to user as result of read. */ int ureadc(int c, struct uio *uio) { struct iovec *iov; if (uio->uio_resid == 0) #ifdef DIAGNOSTIC panic("ureadc: zero resid"); #else return (EINVAL); #endif again: if (uio->uio_iovcnt <= 0) #ifdef DIAGNOSTIC panic("ureadc: non-positive iovcnt"); #else return (EINVAL); #endif iov = uio->uio_iov; if (iov->iov_len <= 0) { uio->uio_iovcnt--; uio->uio_iov++; goto again; } switch (uio->uio_segflg) { case UIO_USERSPACE: { char tmp = c; if (copyout(&tmp, iov->iov_base, sizeof(char)) != 0) return (EFAULT); } break; case UIO_SYSSPACE: *(char *)iov->iov_base = c; break; } iov->iov_base = (caddr_t)iov->iov_base + 1; iov->iov_len--; uio->uio_resid--; uio->uio_offset++; return (0); } /* * General routine to allocate a hash table. */ void * hashinit(int elements, int type, int flags, u_long *hashmask) { u_long hashsize, i; LIST_HEAD(generic, generic) *hashtbl; if (elements <= 0) panic("hashinit: bad cnt"); for (hashsize = 1; hashsize < elements; hashsize <<= 1) continue; hashtbl = malloc(hashsize * sizeof(*hashtbl), type, flags); if (hashtbl == NULL) return NULL; for (i = 0; i < hashsize; i++) LIST_INIT(&hashtbl[i]); *hashmask = hashsize - 1; return (hashtbl); } /* * "Shutdown/startup hook" types, functions, and variables. */ struct hook_desc_head startuphook_list = TAILQ_HEAD_INITIALIZER(startuphook_list); struct hook_desc_head shutdownhook_list = TAILQ_HEAD_INITIALIZER(shutdownhook_list); struct hook_desc_head mountroothook_list = TAILQ_HEAD_INITIALIZER(mountroothook_list); void * hook_establish(struct hook_desc_head *head, int tail, void (*fn)(void *), void *arg) { struct hook_desc *hdp; hdp = (struct hook_desc *)malloc(sizeof (*hdp), M_DEVBUF, M_NOWAIT); if (hdp == NULL) return (NULL); hdp->hd_fn = fn; hdp->hd_arg = arg; if (tail) TAILQ_INSERT_TAIL(head, hdp, hd_list); else TAILQ_INSERT_HEAD(head, hdp, hd_list); return (hdp); } void hook_disestablish(struct hook_desc_head *head, void *vhook) { struct hook_desc *hdp; #ifdef DIAGNOSTIC for (hdp = TAILQ_FIRST(head); hdp != NULL; hdp = TAILQ_NEXT(hdp, hd_list)) if (hdp == vhook) break; if (hdp == NULL) return; #endif hdp = vhook; TAILQ_REMOVE(head, hdp, hd_list); free(hdp, M_DEVBUF); } /* * Run hooks. Startup hooks are invoked right after scheduler_start but * before root is mounted. Shutdown hooks are invoked immediately before the * system is halted or rebooted, i.e. after file systems unmounted, * after crash dump done, etc. */ void dohooks(struct hook_desc_head *head, int flags) { struct hook_desc *hdp; if ((flags & HOOK_REMOVE) == 0) { TAILQ_FOREACH(hdp, head, hd_list) { (*hdp->hd_fn)(hdp->hd_arg); } } else { while ((hdp = TAILQ_FIRST(head)) != NULL) { TAILQ_REMOVE(head, hdp, hd_list); (*hdp->hd_fn)(hdp->hd_arg); if ((flags & HOOK_FREE) != 0) free(hdp, M_DEVBUF); } } }