xref: /xnu-8792.61.2/bsd/kern/kern_xxx.c (revision 42e220869062b56f8d7d0726fd4c88954f87902c)
1 /*
2  * Copyright (c) 2000-2009 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 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1982, 1986, 1989, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *	This product includes software developed by the University of
44  *	California, Berkeley and its contributors.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)kern_xxx.c	8.2 (Berkeley) 11/14/93
62  */
63 /*
64  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
65  * support for mandatory and extensible security protections.  This notice
66  * is included in support of clause 2.2 (b) of the Apple Public License,
67  * Version 2.0.
68  */
69 
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/kernel.h>
73 #include <sys/proc_internal.h>
74 #include <sys/kauth.h>
75 #include <sys/reboot.h>
76 #include <sys/vm.h>
77 #include <sys/sysctl.h>
78 #include <sys/buf.h>
79 
80 #include <security/audit/audit.h>
81 
82 #include <sys/mount_internal.h>
83 #include <sys/sysproto.h>
84 #if CONFIG_MACF
85 #include <security/mac_framework.h>
86 #endif
87 #if CONFIG_ATM
88 #include <atm/atm_internal.h>
89 #endif
90 
91 #include <kern/kalloc.h>
92 
93 /* Max panic string length */
94 #define kPanicStringMaxLen 1024
95 
96 extern int psem_cache_purge_all(void);
97 extern int pshm_cache_purge_all(void);
98 extern int pshm_cache_purge_uid(uid_t uid);
99 extern void reset_osvariant_status(void);
100 extern void reset_osreleasetype(void);
101 
102 int
reboot(struct proc * p,struct reboot_args * uap,__unused int32_t * retval)103 reboot(struct proc *p, struct reboot_args *uap, __unused int32_t *retval)
104 {
105 	char *message = NULL;
106 	int error = 0;
107 	size_t dummy = 0;
108 #if CONFIG_MACF
109 	kauth_cred_t my_cred;
110 #endif
111 
112 	AUDIT_ARG(cmd, uap->opt);
113 
114 	if ((error = suser(kauth_cred_get(), &p->p_acflag))) {
115 #if (DEVELOPMENT || DEBUG)
116 		if (uap->opt & RB_PANIC) {
117 			/* clear 'error' to allow non-root users to call panic on dev/debug kernels */
118 			error = 0;
119 		} else {
120 			return error;
121 		}
122 #else
123 		return error;
124 #endif
125 	}
126 
127 	if (uap->opt & RB_PANIC && uap->msg != USER_ADDR_NULL) {
128 		message = (char *)kalloc_data(kPanicStringMaxLen, Z_WAITOK | Z_ZERO);
129 		if (!message) {
130 			return ENOMEM;
131 		}
132 		int copy_error = copyinstr(uap->msg, (void *)message, kPanicStringMaxLen, (size_t *)&dummy);
133 		if (copy_error != 0 && copy_error != ENAMETOOLONG) {
134 			strncpy(message, "user space RB_PANIC message copyin failed", kPanicStringMaxLen - 1);
135 		} else {
136 			message[kPanicStringMaxLen - 1] = '\0';
137 		}
138 	}
139 
140 #if CONFIG_MACF
141 #if (DEVELOPMENT || DEBUG)
142 	if (uap->opt & RB_PANIC) {
143 		/* on dev/debug kernels: allow anyone to call panic */
144 		goto skip_cred_check;
145 	}
146 #endif
147 
148 	my_cred = kauth_cred_proc_ref(p);
149 	error = mac_system_check_reboot(my_cred, uap->opt);
150 	kauth_cred_unref(&my_cred);
151 #if (DEVELOPMENT || DEBUG)
152 skip_cred_check:
153 #endif
154 #endif
155 	if (!error) {
156 		OSBitOrAtomic(P_REBOOT, &p->p_flag);  /* No more signals for this proc */
157 		error = reboot_kernel(uap->opt, message);
158 	}
159 
160 	kfree_data(message, kPanicStringMaxLen);
161 	return error;
162 }
163 
164 extern void OSKextResetAfterUserspaceReboot(void);
165 extern void zone_gc_drain(void);
166 extern uint64_t pmap_release_pages_fast(void);
167 
168 static int
usrctl_full(void)169 usrctl_full(void)
170 {
171 	reset_osvariant_status();
172 	reset_osreleasetype();
173 
174 #if CONFIG_ATM
175 	atm_reset();
176 #endif
177 
178 #if CONFIG_EXT_RESOLVER
179 	/*
180 	 * We're doing a user space reboot.  We are guaranteed that the
181 	 * external identity resolver is gone, so ensure that everything
182 	 * comes back up as with fresh-boot just in case it didn't go
183 	 * down cleanly.
184 	 */
185 	kauth_resolver_identity_reset();
186 #endif /* CONFIG_EXT_RESOLVER */
187 
188 	OSKextResetAfterUserspaceReboot();
189 	int shm_error = pshm_cache_purge_all();
190 	int sem_error = psem_cache_purge_all();
191 
192 	zone_gc_drain();
193 	pmap_release_pages_fast();
194 
195 	return shm_error != 0 ? shm_error : sem_error;
196 }
197 
198 static int
usrctl_logout(uid_t uid)199 usrctl_logout(uid_t uid)
200 {
201 	int shm_error = pshm_cache_purge_uid(uid);
202 	/*
203 	 * Currently there is a requirement to purge some root-owned semaphores,
204 	 * and no use-case for preserving any. Just purge all of them.
205 	 */
206 	int sem_error = psem_cache_purge_all();
207 
208 	/*
209 	 * Until rdar://78965143, kern.willuserspacereboot is set when logout begins
210 	 * so its effects need to be reset here, when logout completes.
211 	 */
212 	OSKextResetAfterUserspaceReboot();
213 
214 	return shm_error != 0 ? shm_error : sem_error;
215 }
216 
217 int
usrctl(struct proc * p,struct usrctl_args * uap,__unused int32_t * retval)218 usrctl(struct proc *p, struct usrctl_args *uap, __unused int32_t *retval)
219 {
220 	if (p != initproc) {
221 		return EPERM;
222 	}
223 
224 	if (uap->flags == 0) {
225 		return usrctl_full();
226 	} else {
227 		return usrctl_logout((uid_t)uap->flags);
228 	}
229 }
230