NetBSD/sys/kern/kern_subr.c

235 lines
5.8 KiB
C

/* $NetBSD: kern_subr.c,v 1.16 1996/10/13 02:27:52 christos 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(buf, n, uio)
register void *buf;
register int n;
register struct uio *uio;
{
register struct iovec *iov;
u_int cnt;
int error = 0;
char *cp = buf;
#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(cp, iov->iov_base, cnt);
else
bcopy(iov->iov_base, 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:
*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);
}