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 * @OSF_COPYRIGHT@
30 */
31 /*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or [email protected]
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56 /*
57 */
58 /*
59 * File: ipc/ipc_table.c
60 * Author: Rich Draves
61 * Date: 1989
62 *
63 * Functions to manipulate tables of IPC capabilities.
64 */
65
66 #include <mach/kern_return.h>
67 #include <mach/vm_param.h>
68 #include <ipc/ipc_table.h>
69 #include <ipc/ipc_port.h>
70 #include <ipc/ipc_entry.h>
71 #include <kern/kalloc.h>
72 #include <kern/hazard.h>
73 #include <vm/vm_kern.h>
74
75 #define IPC_TABLE_ENTRIES_SIZE CONFIG_IPC_TABLE_ENTRIES_STEPS
76 SECURITY_READ_ONLY_LATE(struct ipc_table_size) ipc_table_entries[IPC_TABLE_ENTRIES_SIZE];
77
78 #define IPC_TABLE_REQUESTS_SIZE 64
79 SECURITY_READ_ONLY_LATE(struct ipc_table_size) ipc_table_requests[IPC_TABLE_REQUESTS_SIZE];
80
81 KALLOC_TYPE_VAR_DEFINE(kt_var_it_entries, struct ipc_entry, KT_PRIV_ACCT);
82
83 static void
ipc_table_fill(ipc_table_size_t its,unsigned int num,unsigned int min,vm_size_t elemsize)84 ipc_table_fill(
85 ipc_table_size_t its, /* array to fill */
86 unsigned int num, /* size of array */
87 unsigned int min, /* at least this many elements */
88 vm_size_t elemsize) /* size of elements */
89 {
90 unsigned int index;
91 vm_size_t minsize = min * elemsize;
92 vm_size_t size;
93 vm_size_t incrsize;
94
95 /* first use powers of two, up to the page size */
96
97 for (index = 0, size = 1;
98 (index < num) && (size < PAGE_MAX_SIZE);
99 size <<= 1) {
100 if (size >= minsize) {
101 its[index].its_size = (ipc_table_elems_t)(size / elemsize);
102 index++;
103 }
104 }
105
106 /* then increments of a page, then two pages, etc. */
107
108 for (incrsize = PAGE_MAX_SIZE; index < num;) {
109 unsigned int period;
110
111 for (period = 0;
112 (period < 15) && (index < num);
113 period++, size += incrsize) {
114 if (size >= minsize) {
115 its[index].its_size = (ipc_table_elems_t)(size / elemsize);
116 index++;
117 }
118 }
119 if (incrsize < (vm_size_t)(PAGE_MAX_SIZE << 3)) {
120 incrsize <<= 1;
121 }
122 }
123 }
124
125 __startup_func
126 static void
ipc_table_init(void)127 ipc_table_init(void)
128 {
129 ipc_table_fill(ipc_table_entries, IPC_TABLE_ENTRIES_SIZE - 1,
130 16, sizeof(struct ipc_entry));
131
132 /* the last two elements should have the same size */
133
134 ipc_table_entries[IPC_TABLE_ENTRIES_SIZE - 1].its_size =
135 ipc_table_entries[IPC_TABLE_ENTRIES_SIZE - 2].its_size;
136
137 /* make sure the robin hood hashing in ipc hash will work */
138 assert(ipc_table_entries[IPC_TABLE_ENTRIES_SIZE - 1].its_size <=
139 IPC_ENTRY_INDEX_MAX);
140
141 ipc_table_fill(ipc_table_requests, IPC_TABLE_REQUESTS_SIZE - 1,
142 2, sizeof(struct ipc_port_request));
143
144 /* the last element should have zero size */
145
146 ipc_table_requests[IPC_TABLE_REQUESTS_SIZE - 1].its_size = 0;
147 }
148 STARTUP(MACH_IPC, STARTUP_RANK_FIRST, ipc_table_init);
149
150
151 /*
152 * Routine: ipc_table_max_entries
153 * Purpose:
154 * returns the maximum number of entries an IPC space
155 * is allowed to contain (the maximum size to which it will grow)
156 * Conditions:
157 * none
158 */
159 unsigned int
ipc_table_max_entries(void)160 ipc_table_max_entries(void)
161 {
162 static_assert(IPC_TABLE_ENTRIES_SIZE >= 1);
163 return (unsigned int)ipc_table_entries[IPC_TABLE_ENTRIES_SIZE - 1].its_size;
164 }
165
166
167 /*
168 * Routine: ipc_table_max_requests
169 * Purpose:
170 * returns the maximum number of requests an IPC request table
171 * is allowed to contain (the maximum size to which it will grow)
172 * Conditions:
173 * none
174 */
175 unsigned int
ipc_table_max_requests(void)176 ipc_table_max_requests(void)
177 {
178 static_assert(IPC_TABLE_REQUESTS_SIZE >= 2);
179 return (unsigned int)ipc_table_requests[IPC_TABLE_REQUESTS_SIZE - 2].its_size;
180 }
181