1 | /* |
2 | * Copyright (c) 2000-2016 Apple 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 | /* |
71 | * Memory special file |
72 | */ |
73 | |
74 | #include <sys/param.h> |
75 | #include <sys/dir.h> |
76 | #include <sys/proc.h> |
77 | #include <sys/systm.h> |
78 | #include <sys/conf.h> |
79 | #include <sys/vm.h> |
80 | #include <sys/uio_internal.h> |
81 | #include <sys/malloc.h> |
82 | |
83 | #include <mach/vm_types.h> |
84 | #include <mach/vm_param.h> |
85 | #include <vm/vm_kern.h> /* for kernel_map */ |
86 | |
87 | #include <pexpert/pexpert.h> /* for PE_parse_boot_argn */ |
88 | |
89 | boolean_t iskmemdev(dev_t dev); |
90 | |
91 | #if CONFIG_DEV_KMEM |
92 | boolean_t dev_kmem_enabled; |
93 | boolean_t dev_kmem_mask_top_bit; |
94 | |
95 | void dev_kmem_init(void); |
96 | |
97 | #if defined(__x86_64__) |
98 | extern addr64_t kvtophys(vm_offset_t va); |
99 | #else |
100 | #error need kvtophys prototype |
101 | #endif |
102 | extern boolean_t kernacc(off_t, size_t ); |
103 | |
104 | #endif |
105 | |
106 | static caddr_t devzerobuf; |
107 | |
108 | int mmread(dev_t dev, struct uio *uio); |
109 | int mmwrite(dev_t dev, struct uio *uio); |
110 | int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p); |
111 | int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw); |
112 | |
113 | int |
114 | mmread(dev_t dev, struct uio *uio) |
115 | { |
116 | return (mmrw(dev, uio, UIO_READ)); |
117 | } |
118 | |
119 | int |
120 | mmwrite(dev_t dev, struct uio *uio) |
121 | { |
122 | return (mmrw(dev, uio, UIO_WRITE)); |
123 | } |
124 | |
125 | int |
126 | mmioctl(dev_t dev, u_long cmd, __unused caddr_t data, |
127 | __unused int flag, __unused struct proc *p) |
128 | { |
129 | int minnum = minor(dev); |
130 | |
131 | if (0 == minnum || 1 == minnum) { |
132 | /* /dev/mem and /dev/kmem */ |
133 | #if CONFIG_DEV_KMEM |
134 | if (!dev_kmem_enabled) |
135 | return (ENODEV); |
136 | #else |
137 | return (ENODEV); |
138 | #endif |
139 | } |
140 | |
141 | switch (cmd) { |
142 | case FIONBIO: |
143 | case FIOASYNC: |
144 | /* OK to do nothing: we always return immediately */ |
145 | break; |
146 | default: |
147 | return ENODEV; |
148 | } |
149 | |
150 | return (0); |
151 | } |
152 | |
153 | int |
154 | mmrw(dev_t dev, struct uio *uio, enum uio_rw rw) |
155 | { |
156 | unsigned int c; |
157 | int error = 0; |
158 | |
159 | while (uio_resid(uio) > 0) { |
160 | uio_update(uio, 0); |
161 | |
162 | switch (minor(dev)) { |
163 | |
164 | /* minor device 0 is physical memory */ |
165 | case 0: |
166 | return (ENODEV); |
167 | |
168 | /* minor device 1 is kernel memory */ |
169 | case 1: |
170 | #if !CONFIG_DEV_KMEM |
171 | return (ENODEV); |
172 | #else /* CONFIG_DEV_KMEM */ |
173 | if (!dev_kmem_enabled) |
174 | return (ENODEV); |
175 | |
176 | vm_address_t kaddr = (vm_address_t)uio->uio_offset; |
177 | if (dev_kmem_mask_top_bit) { |
178 | /* |
179 | * KVA addresses of the form 0xFFFFFF80AABBCCDD can't be |
180 | * represented as a signed off_t correctly. In these cases, |
181 | * 0x7FFFFF80AABBCCDD is passed in, and the top bit OR-ed |
182 | * on. |
183 | */ |
184 | const vm_address_t top_bit = (~((vm_address_t)0)) ^ (~((vm_address_t)0) >> 1UL); |
185 | if (kaddr & top_bit) { |
186 | /* top bit should not be set already */ |
187 | return (EFAULT); |
188 | } |
189 | kaddr |= top_bit; |
190 | } |
191 | |
192 | c = uio_curriovlen(uio); |
193 | |
194 | /* Do some sanity checking */ |
195 | if ((kaddr > (VM_MAX_KERNEL_ADDRESS - c)) || |
196 | (kaddr <= VM_MIN_KERNEL_AND_KEXT_ADDRESS)) |
197 | goto fault; |
198 | if (!kernacc(kaddr, c)) |
199 | goto fault; |
200 | error = uiomove((const char *)(uintptr_t)kaddr, |
201 | (int)c, uio); |
202 | if (error) |
203 | break; |
204 | |
205 | continue; /* Keep going until UIO is done */ |
206 | #endif /* CONFIG_DEV_KMEM */ |
207 | |
208 | /* minor device 2 is EOF/RATHOLE */ |
209 | case 2: |
210 | if (rw == UIO_READ) |
211 | return (0); |
212 | c = uio_curriovlen(uio); |
213 | |
214 | error = 0; /* Always succeeds, always consumes all input */ |
215 | break; |
216 | case 3: |
217 | if(devzerobuf == NULL) { |
218 | MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK); |
219 | bzero(devzerobuf, PAGE_SIZE); |
220 | } |
221 | if(uio->uio_rw == UIO_WRITE) { |
222 | c = uio_curriovlen(uio); |
223 | |
224 | error = 0; /* Always succeeds, always consumes all input */ |
225 | break; |
226 | } |
227 | |
228 | c = min(uio_curriovlen(uio), PAGE_SIZE); |
229 | error = uiomove(devzerobuf, (int)c, uio); |
230 | if (error) |
231 | break; |
232 | |
233 | continue; /* Keep going until UIO is done */ |
234 | default: |
235 | return (ENODEV); |
236 | } |
237 | |
238 | if (error) |
239 | break; |
240 | |
241 | uio_update(uio, c); |
242 | } |
243 | return (error); |
244 | #if CONFIG_DEV_KMEM |
245 | fault: |
246 | return (EFAULT); |
247 | #endif |
248 | } |
249 | |
250 | #if CONFIG_DEV_KMEM |
251 | void dev_kmem_init(void) |
252 | { |
253 | uint32_t kmem; |
254 | |
255 | if (PE_i_can_has_debugger(NULL) && |
256 | PE_parse_boot_argn("kmem" , &kmem, sizeof (kmem))) { |
257 | if (kmem & 0x1) { |
258 | dev_kmem_enabled = TRUE; |
259 | } |
260 | if (kmem & 0x2) { |
261 | dev_kmem_mask_top_bit = TRUE; |
262 | } |
263 | } |
264 | } |
265 | |
266 | boolean_t |
267 | kernacc( |
268 | off_t start, |
269 | size_t len |
270 | ) |
271 | { |
272 | off_t base; |
273 | off_t end; |
274 | |
275 | base = trunc_page(start); |
276 | end = start + len; |
277 | |
278 | while (base < end) { |
279 | if(kvtophys((vm_offset_t)base) == 0ULL) |
280 | return(FALSE); |
281 | base += page_size; |
282 | } |
283 | |
284 | return (TRUE); |
285 | } |
286 | |
287 | #endif /* CONFIG_DEV_KMEM */ |
288 | |
289 | /* |
290 | * Returns true if dev is /dev/mem or /dev/kmem. |
291 | */ |
292 | boolean_t iskmemdev(dev_t dev) |
293 | { |
294 | return (major(dev) == 3 && minor(dev) < 2); |
295 | } |
296 | |