326 lines
8.0 KiB
C
326 lines
8.0 KiB
C
/* $OpenBSD: kern_subr.c,v 1.52 2023/01/31 15:18:56 deraadt Exp $ */
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/* $NetBSD: kern_subr.c,v 1.15 1996/04/09 17:21:56 ragge Exp $ */
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/*
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* Copyright (c) 1982, 1986, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/sched.h>
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#include <sys/malloc.h>
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#include <sys/queue.h>
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#include <uvm/uvm_extern.h>
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#ifdef PMAP_CHECK_COPYIN
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static inline int check_copyin(struct proc *, const void *, size_t);
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extern int _copyinstr(const void *, void *, size_t, size_t *);
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extern int _copyin(const void *uaddr, void *kaddr, size_t len);
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/*
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* If range overlaps an check_copyin region, return EFAULT
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*/
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static inline int
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check_copyin(struct proc *p, const void *vstart, size_t len)
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{
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struct vm_map *map = &p->p_vmspace->vm_map;
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const vaddr_t start = (vaddr_t)vstart;
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const vaddr_t end = start + len;
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int i, max;
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/* XXX if the array was sorted, we could shortcut */
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max = map->check_copyin_count;
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membar_consumer();
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for (i = 0; i < max; i++) {
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vaddr_t s = map->check_copyin[i].start;
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vaddr_t e = map->check_copyin[i].end;
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if ((start >= s && start < e) || (end > s && end < e))
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return EFAULT;
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}
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return (0);
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}
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int
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copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done)
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{
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size_t alen;
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int error;
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/*
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* Must do the copyin checks after figuring out the string length,
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* the buffer size length may cross into another ELF segment
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*/
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error = _copyinstr(uaddr, kaddr, len, &alen);
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if (PMAP_CHECK_COPYIN && error == 0)
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error = check_copyin(curproc, uaddr, alen);
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if (done)
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*done = alen;
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return (error);
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}
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int
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copyin(const void *uaddr, void *kaddr, size_t len)
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{
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int error = 0;
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if (PMAP_CHECK_COPYIN)
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error = check_copyin(curproc, uaddr, len);
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if (error == 0)
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error = _copyin(uaddr, kaddr, len);
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return (error);
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}
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#endif /* PMAP_CHECK_COPYIN */
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int
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uiomove(void *cp, size_t n, struct uio *uio)
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{
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struct iovec *iov;
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size_t cnt;
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int error = 0;
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#ifdef DIAGNOSTIC
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if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
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panic("uiomove: mode");
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if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
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panic("uiomove: proc");
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#endif
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if (n > uio->uio_resid)
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n = uio->uio_resid;
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while (n > 0) {
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iov = uio->uio_iov;
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cnt = iov->iov_len;
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if (cnt == 0) {
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KASSERT(uio->uio_iovcnt > 0);
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uio->uio_iov++;
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uio->uio_iovcnt--;
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continue;
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}
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if (cnt > n)
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cnt = n;
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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sched_pause(preempt);
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if (uio->uio_rw == UIO_READ)
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error = copyout(cp, iov->iov_base, cnt);
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else
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error = copyin(iov->iov_base, cp, cnt);
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if (error)
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return (error);
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break;
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case UIO_SYSSPACE:
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if (uio->uio_rw == UIO_READ)
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error = kcopy(cp, iov->iov_base, cnt);
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else
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error = kcopy(iov->iov_base, cp, cnt);
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if (error)
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return(error);
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}
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iov->iov_base = (caddr_t)iov->iov_base + cnt;
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iov->iov_len -= cnt;
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uio->uio_resid -= cnt;
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uio->uio_offset += cnt;
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cp = (caddr_t)cp + cnt;
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n -= cnt;
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}
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return (error);
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}
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/*
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* Give next character to user as result of read.
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*/
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int
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ureadc(int c, struct uio *uio)
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{
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struct iovec *iov;
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if (uio->uio_resid == 0)
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#ifdef DIAGNOSTIC
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panic("ureadc: zero resid");
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#else
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return (EINVAL);
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#endif
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again:
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if (uio->uio_iovcnt <= 0)
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#ifdef DIAGNOSTIC
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panic("ureadc: non-positive iovcnt");
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#else
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return (EINVAL);
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#endif
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iov = uio->uio_iov;
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if (iov->iov_len <= 0) {
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uio->uio_iovcnt--;
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uio->uio_iov++;
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goto again;
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}
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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{
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char tmp = c;
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if (copyout(&tmp, iov->iov_base, sizeof(char)) != 0)
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return (EFAULT);
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}
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break;
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case UIO_SYSSPACE:
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*(char *)iov->iov_base = c;
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break;
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}
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iov->iov_base = (caddr_t)iov->iov_base + 1;
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iov->iov_len--;
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uio->uio_resid--;
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uio->uio_offset++;
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return (0);
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}
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/*
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* General routine to allocate a hash table.
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*/
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void *
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hashinit(int elements, int type, int flags, u_long *hashmask)
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{
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u_long hashsize, i;
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LIST_HEAD(generic, generic) *hashtbl;
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if (elements <= 0)
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panic("hashinit: bad cnt");
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if ((elements & (elements - 1)) == 0)
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hashsize = elements;
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else
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for (hashsize = 1; hashsize < elements; hashsize <<= 1)
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continue;
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hashtbl = mallocarray(hashsize, sizeof(*hashtbl), type, flags);
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if (hashtbl == NULL)
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return NULL;
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for (i = 0; i < hashsize; i++)
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LIST_INIT(&hashtbl[i]);
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*hashmask = hashsize - 1;
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return (hashtbl);
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}
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void
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hashfree(void *hash, int elements, int type)
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{
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u_long hashsize;
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LIST_HEAD(generic, generic) *hashtbl = hash;
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if (elements <= 0)
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panic("hashfree: bad cnt");
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if ((elements & (elements - 1)) == 0)
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hashsize = elements;
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else
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for (hashsize = 1; hashsize < elements; hashsize <<= 1)
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continue;
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free(hashtbl, type, sizeof(*hashtbl) * hashsize);
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}
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/*
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* "startup hook" types, functions, and variables.
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*/
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struct hook_desc_head startuphook_list =
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TAILQ_HEAD_INITIALIZER(startuphook_list);
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void *
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hook_establish(struct hook_desc_head *head, int tail, void (*fn)(void *),
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void *arg)
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{
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struct hook_desc *hdp;
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hdp = malloc(sizeof(*hdp), M_DEVBUF, M_NOWAIT);
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if (hdp == NULL)
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return (NULL);
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hdp->hd_fn = fn;
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hdp->hd_arg = arg;
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if (tail)
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TAILQ_INSERT_TAIL(head, hdp, hd_list);
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else
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TAILQ_INSERT_HEAD(head, hdp, hd_list);
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return (hdp);
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}
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void
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hook_disestablish(struct hook_desc_head *head, void *vhook)
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{
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struct hook_desc *hdp;
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#ifdef DIAGNOSTIC
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for (hdp = TAILQ_FIRST(head); hdp != NULL;
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hdp = TAILQ_NEXT(hdp, hd_list))
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if (hdp == vhook)
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break;
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if (hdp == NULL)
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return;
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#endif
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hdp = vhook;
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TAILQ_REMOVE(head, hdp, hd_list);
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free(hdp, M_DEVBUF, sizeof(*hdp));
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}
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/*
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* Run hooks. Startup hooks are invoked right after scheduler_start but
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* before root is mounted. Shutdown hooks are invoked immediately before the
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* system is halted or rebooted, i.e. after file systems unmounted,
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* after crash dump done, etc.
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*/
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void
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dohooks(struct hook_desc_head *head, int flags)
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{
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struct hook_desc *hdp, *hdp_temp;
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if ((flags & HOOK_REMOVE) == 0) {
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TAILQ_FOREACH_SAFE(hdp, head, hd_list, hdp_temp) {
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(*hdp->hd_fn)(hdp->hd_arg);
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}
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} else {
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while ((hdp = TAILQ_FIRST(head)) != NULL) {
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TAILQ_REMOVE(head, hdp, hd_list);
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(*hdp->hd_fn)(hdp->hd_arg);
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if ((flags & HOOK_FREE) != 0)
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free(hdp, M_DEVBUF, sizeof(*hdp));
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}
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}
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}
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