xref: /xnu-11417.140.69/bsd/vm/dp_backing_file.c (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
1 /*
2  * Copyright (c) 2000-2010 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  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
30  * support for mandatory and extensible security protections.  This notice
31  * is included in support of clause 2.2 (b) of the Apple Public License,
32  * Version 2.0.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/lock.h>
38 #include <sys/proc_internal.h>
39 #include <sys/kauth.h>
40 #include <sys/buf.h>
41 #include <sys/uio.h>
42 #include <sys/vnode_internal.h>
43 #include <sys/namei.h>
44 #include <sys/ubc_internal.h>
45 #include <sys/malloc.h>
46 #include <sys/user.h>
47 
48 #include <default_pager/default_pager_types.h>
49 
50 #include <security/audit/audit.h>
51 #include <bsm/audit_kevents.h>
52 
53 #include <mach/mach_types.h>
54 #include <mach/host_priv.h>
55 #include <mach/mach_traps.h>
56 #include <mach/boolean.h>
57 
58 #include <kern/kern_types.h>
59 #include <kern/locks.h>
60 #include <kern/host.h>
61 #include <kern/task.h>
62 #include <kern/zalloc.h>
63 #include <kern/policy_internal.h>
64 
65 #include <libkern/libkern.h>
66 
67 #include <vm/vm_pageout.h>
68 #include <vm/vm_map.h>
69 #include <vm/vm_kern.h>
70 #include <vm/vnode_pager.h>
71 #include <vm/vm_protos_internal.h>
72 #include <vm/vm_compressor_backing_store_xnu.h>
73 #if CONFIG_MACF
74 #include <security/mac_framework.h>
75 #endif
76 
77 #include <pexpert/pexpert.h>
78 
79 
80 /*
81  *	Routine:	macx_backing_store_recovery
82  *	Function:
83  *		Syscall interface to set a tasks privilege
84  *		level so that it is not subject to
85  *		macx_backing_store_suspend
86  */
87 int
macx_backing_store_recovery(__unused struct macx_backing_store_recovery_args * args)88 macx_backing_store_recovery(
89 	__unused struct macx_backing_store_recovery_args *args)
90 {
91 	return ENOTSUP;
92 }
93 
94 /*
95  *	Routine:	macx_backing_store_suspend
96  *	Function:
97  *		Syscall interface to stop new demand for
98  *		backing store when backing store is low
99  */
100 
101 int
macx_backing_store_suspend(__unused struct macx_backing_store_suspend_args * args)102 macx_backing_store_suspend(
103 	__unused struct macx_backing_store_suspend_args *args)
104 {
105 	return ENOTSUP;
106 }
107 
108 
109 extern boolean_t compressor_store_stop_compaction;
110 
111 /*
112  *	Routine:	macx_backing_store_compaction
113  *	Function:
114  *		Turn compaction of swap space on or off.  This is
115  *		used during shutdown/restart so	that the kernel
116  *		doesn't waste time compacting swap files that are
117  *		about to be deleted anyway.  Compaction	is always
118  *		on by default when the system comes up and is turned
119  *		off when a shutdown/restart is requested.  It is
120  *		re-enabled if the shutdown/restart is aborted for any reason.
121  *
122  *  This routine assumes macx_lock has been locked by macx_triggers ->
123  *      mach_macx_triggers -> macx_backing_store_compaction
124  */
125 extern int vm_swap_enabled;
126 int
macx_backing_store_compaction(int flags)127 macx_backing_store_compaction(int flags)
128 {
129 	int error;
130 
131 	if ((error = suser(kauth_cred_get(), 0))) {
132 		return error;
133 	}
134 
135 	if (flags & SWAP_COMPACT_DISABLE) {
136 #if (XNU_TARGET_OS_OSX && __arm64__)
137 		/*
138 		 * There's no synch. between the swap being turned
139 		 * OFF from user-space and all processes having exited.
140 		 * On fast SSD AS macs we can accumulate a lot of
141 		 * compressed memory between those 2 operations.
142 		 * So we allow swap till we are ready to shutdown the
143 		 * system. Even with a bunch of processes
144 		 * still running and creating a lot of compressed
145 		 * memory the system can shutdown normally.
146 		 */
147 #else /* (XNU_TARGET_OS_OSX && __arm64__) */
148 		compressor_store_stop_compaction = TRUE;
149 		vm_swap_enabled = 0;
150 		kprintf("compressor_store_stop_compaction = TRUE\n");
151 #endif /* (XNU_TARGET_OS_OSX && __arm64__) */
152 	} else if (flags & SWAP_COMPACT_ENABLE) {
153 		compressor_store_stop_compaction = FALSE;
154 		vm_swap_enabled = 1;
155 		kprintf("compressor_store_stop_compaction = FALSE\n");
156 	}
157 
158 	return 0;
159 }
160 
161 /*
162  *	Routine:	macx_triggers
163  *	Function:
164  *		Syscall interface to set the call backs for low and
165  *		high water marks.
166  */
167 int
macx_triggers(struct macx_triggers_args * args)168 macx_triggers(
169 	struct macx_triggers_args *args)
170 {
171 	int     flags = args->flags;
172 
173 	if (flags & (SWAP_COMPACT_DISABLE | SWAP_COMPACT_ENABLE)) {
174 		return macx_backing_store_compaction(flags);
175 	}
176 
177 	return ENOTSUP;
178 }
179 
180 
181 int
macx_swapon(__unused struct macx_swapon_args * args)182 macx_swapon(
183 	__unused struct macx_swapon_args *args)
184 {
185 	return ENOTSUP;
186 }
187 
188 
189 /*
190  *	Routine:	macx_swapoff
191  *	Function:
192  *		Syscall interface to remove a file from backing store
193  */
194 int
macx_swapoff(__unused struct macx_swapoff_args * args)195 macx_swapoff(
196 	__unused struct macx_swapoff_args *args)
197 {
198 	return ENOTSUP;
199 }
200 
201 /*
202  *	Routine:	macx_swapinfo
203  *	Function:
204  *		Syscall interface to get general swap statistics
205  */
206 extern boolean_t vm_swap_up;
207 
208 int
macx_swapinfo(memory_object_size_t * total_p,memory_object_size_t * avail_p,vm_size_t * pagesize_p,boolean_t * encrypted_p)209 macx_swapinfo(
210 	memory_object_size_t    *total_p,
211 	memory_object_size_t    *avail_p,
212 	vm_size_t               *pagesize_p,
213 	boolean_t               *encrypted_p)
214 {
215 	if (VM_CONFIG_SWAP_IS_PRESENT) {
216 		*total_p = vm_swap_get_total_space();
217 		*avail_p = vm_swap_get_free_space();
218 		*pagesize_p = (vm_size_t)PAGE_SIZE_64;
219 		*encrypted_p = TRUE;
220 	} else {
221 		*total_p = 0;
222 		*avail_p = 0;
223 		*pagesize_p = 0;
224 		*encrypted_p = FALSE;
225 	}
226 	return 0;
227 }
228