1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*-
29 * Copyright (c) 1988 University of Utah.
30 * Copyright (c) 1982, 1986, 1990, 1993
31 *	The Regents of the University of California.  All rights reserved.
32 *
33 * This code is derived from software contributed to Berkeley by
34 * the Systems Programming Group of the University of Utah Computer
35 * Science Department, and code derived from software contributed to
36 * Berkeley by William Jolitz.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 *    notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 *    notice, this list of conditions and the following disclaimer in the
45 *    documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 *    must display the following acknowledgement:
48 *	This product includes software developed by the University of
49 *	California, Berkeley and its contributors.
50 * 4. Neither the name of the University nor the names of its contributors
51 *    may be used to endorse or promote products derived from this software
52 *    without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 *
66 * from: Utah $Hdr: mem.c 1.13 89/10/08$
67 *	@(#)mem.c	8.1 (Berkeley) 6/11/93
68 */
69
70#include <mach_load.h>
71
72/*
73 * Memory special file
74 */
75
76#include <sys/param.h>
77#include <sys/dir.h>
78#include <sys/proc.h>
79#include <sys/systm.h>
80#include <sys/conf.h>
81#include <sys/vm.h>
82#include <sys/uio_internal.h>
83#include <sys/malloc.h>
84
85#include <mach/vm_types.h>
86#include <mach/vm_param.h>
87#include <vm/vm_kern.h>		/* for kernel_map */
88
89extern addr64_t  kvtophys(vm_offset_t va);
90extern boolean_t kernacc(off_t, size_t );
91#if !defined(SECURE_KERNEL)
92extern int setup_kmem;
93#endif
94
95static caddr_t devzerobuf;
96
97int mmread(dev_t dev, struct uio *uio);
98int mmwrite(dev_t dev, struct uio *uio);
99int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p);
100int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw);
101
102int
103mmread(dev_t dev, struct uio *uio)
104{
105
106	return (mmrw(dev, uio, UIO_READ));
107}
108
109int
110mmwrite(dev_t dev, struct uio *uio)
111{
112
113	return (mmrw(dev, uio, UIO_WRITE));
114}
115
116int
117mmioctl(dev_t dev, u_long cmd, __unused caddr_t data,
118		__unused int flag, __unused struct proc *p)
119{
120	int minnum = minor(dev);
121
122	if (0 == minnum || 1 == minnum) {
123		/* /dev/mem and /dev/kmem */
124#if defined(SECURE_KERNEL)
125		return (ENODEV);
126#else
127		if (0 == setup_kmem)
128			return (EINVAL);
129#endif
130	}
131
132	switch (cmd) {
133	case FIONBIO:
134	case FIOASYNC:
135		/* OK to do nothing: we always return immediately */
136		break;
137	default:
138		return ENODEV;
139	}
140
141	return (0);
142}
143
144int
145mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
146{
147	register int o;
148	register u_int c, v;
149	int error = 0;
150	vm_offset_t	where;
151	vm_size_t size;
152
153
154	while (uio_resid(uio) > 0 && error == 0) {
155		uio_update(uio, 0);
156
157		switch (minor(dev)) {
158
159		/* minor device 0 is physical memory */
160		case 0:
161#if defined(SECURE_KERNEL)
162			return(ENODEV);
163#else
164			if (setup_kmem == 0)
165				return(ENODEV);
166#endif
167
168			v = trunc_page(uio->uio_offset);
169			if (uio->uio_offset >= (off_t)mem_size)
170				goto fault;
171
172			size= PAGE_SIZE;
173			if (kmem_alloc(kernel_map, &where, size)
174				!= KERN_SUCCESS) {
175				goto fault;
176			}
177			o = uio->uio_offset - v;
178			c = min(PAGE_SIZE - o, uio_curriovlen(uio));
179			error = uiomove((caddr_t) (where + o), c, uio);
180			kmem_free(kernel_map, where, PAGE_SIZE);
181			continue;
182
183		/* minor device 1 is kernel memory */
184		case 1:
185#if defined(SECURE_KERNEL)
186			return(ENODEV);
187#else
188			if (setup_kmem == 0)
189				return(ENODEV);
190#endif
191			/* Do some sanity checking */
192			if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
193				((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_AND_KEXT_ADDRESS))
194				goto fault;
195			c = uio_curriovlen(uio);
196			if (!kernacc(uio->uio_offset, c))
197				goto fault;
198			error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
199					(int)c, uio);
200			continue;
201
202		/* minor device 2 is EOF/RATHOLE */
203		case 2:
204			if (rw == UIO_READ)
205				return (0);
206			c = uio_curriovlen(uio);
207			break;
208		case 3:
209			if(devzerobuf == NULL) {
210				MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
211				bzero(devzerobuf, PAGE_SIZE);
212			}
213			if(uio->uio_rw == UIO_WRITE) {
214				c = uio_curriovlen(uio);
215				break;
216			}
217 			c = min(uio_curriovlen(uio), PAGE_SIZE);
218			error = uiomove(devzerobuf, (int)c, uio);
219			continue;
220		default:
221			goto fault;
222			break;
223		}
224
225		if (error)
226			break;
227		uio_update(uio, c);
228	}
229	return (error);
230fault:
231	return (EFAULT);
232}
233
234
235boolean_t
236kernacc(
237    off_t 	start,
238    size_t	len
239)
240{
241	off_t base;
242	off_t end;
243
244	base = trunc_page(start);
245	end = start + len;
246
247	while (base < end) {
248	  if(kvtophys((vm_offset_t)base) == 0ULL)
249			return(FALSE);
250		base += page_size;
251	}
252
253	return (TRUE);
254}
255