xref: /dflybsd-src/sys/vm/vm_vmspace.c (revision 2bd0301f229264e726c3dcde4fe85699bcc789fa)
1 /*
2  * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vm/vm_vmspace.c,v 1.2 2006/09/17 21:09:40 dillon Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/kernel.h>
39 #include <sys/systm.h>
40 #include <sys/sysproto.h>
41 #include <sys/mman.h>
42 #include <sys/proc.h>
43 #include <sys/malloc.h>
44 #include <sys/sysctl.h>
45 #include <sys/vkernel.h>
46 
47 #include <vm/vm_extern.h>
48 #include <vm/pmap.h>
49 
50 static struct vmspace_entry *vkernel_find_vmspace(struct vkernel *vk, void *id);
51 
52 static MALLOC_DEFINE(M_VKERNEL, "vkernel", "VKernel structures");
53 
54 /*
55  * vmspace_create (void *id, int type, void *data)
56  *
57  * Create a VMSPACE under the control of the caller with the specified id.
58  * An id of NULL cannot be used.  The type and data fields must currently
59  * be 0.
60  *
61  * The vmspace starts out completely empty.  Memory may be mapped into the
62  * VMSPACE with vmspace_mmap() and MAP_VPAGETABLE section(s) controlled
63  * with vmspace_mcontrol().
64  */
65 int
66 sys_vmspace_create(struct vmspace_create_args *uap)
67 {
68 	struct vkernel *vk;
69 	struct vmspace_entry *ve;
70 
71 	if (vkernel_enable == 0)
72 		return (EOPNOTSUPP);
73 
74 	/*
75 	 * Create a virtual kernel side-structure for the process if one
76 	 * does not exist.
77 	 */
78 	if ((vk = curproc->p_vkernel) == NULL) {
79 		vk = kmalloc(sizeof(*vk), M_VKERNEL, M_WAITOK|M_ZERO);
80 		vk->vk_refs = 1;
81 		RB_INIT(&vk->vk_root);
82 		curproc->p_vkernel = vk;
83 	}
84 
85 	/*
86 	 * Create a new VMSPACE
87 	 */
88 	if (vkernel_find_vmspace(vk, uap->id))
89 		return (EEXIST);
90 	ve = kmalloc(sizeof(struct vmspace_entry), M_VKERNEL, M_WAITOK|M_ZERO);
91 	ve->vmspace = vmspace_alloc(VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
92 	ve->id = uap->id;
93 	pmap_pinit2(vmspace_pmap(ve->vmspace));
94 	RB_INSERT(vmspace_rb_tree, &vk->vk_root, ve);
95 	return (0);
96 }
97 
98 /*
99  * vmspace_destroy (void *id)
100  *
101  * Destroy a VMSPACE.
102  */
103 int
104 sys_vmspace_destroy(struct vmspace_destroy_args *uap)
105 {
106 	struct vkernel *vk;
107 	struct vmspace_entry *ve;
108 
109 	if ((vk = curproc->p_vkernel) == NULL)
110 		return (EINVAL);
111 	if ((ve = vkernel_find_vmspace(vk, uap->id)) == NULL)
112 		return (ENOENT);
113 	/* XXX check if active */
114 	RB_REMOVE(vmspace_rb_tree, &vk->vk_root, ve);
115 	vmspace_free(ve->vmspace);
116 	kfree(ve, M_VKERNEL);
117 	return(0);
118 }
119 
120 /*
121  * vmspace_ctl (void *id, int cmd, void *ctx, int ctx_bytes, int timeout_us)
122  *
123  * Transfer control to a VMSPACE.  Control is returned after the specified
124  * number of microseconds or if a page fault, signal, trap, or system call
125  * occurs.
126  */
127 int
128 sys_vmspace_ctl(struct vmspace_ctl_args *uap)
129 {
130 	struct vkernel *vk;
131 	struct vmspace_entry *ve;
132 
133 	if ((vk = curproc->p_vkernel) == NULL)
134 		return (EINVAL);
135 	if ((ve = vkernel_find_vmspace(vk, uap->id)) == NULL)
136 		return (ENOENT);
137 	return(EINVAL);
138 }
139 
140 /*
141  * vmspace_mmap(id, addr, len, prot, flags, fd, offset)
142  *
143  * map memory within a VMSPACE.  This function is just like a normal mmap()
144  * but operates on the vmspace's memory map.  Most callers use this to create
145  * a MAP_VPAGETABLE mapping.
146  */
147 int
148 sys_vmspace_mmap(struct vmspace_mmap_args *uap)
149 {
150 	struct vkernel *vk;
151 	struct vmspace_entry *ve;
152 
153 	if ((vk = curproc->p_vkernel) == NULL)
154 		return (EINVAL);
155 	if ((ve = vkernel_find_vmspace(vk, uap->id)) == NULL)
156 		return (ENOENT);
157 	return(EINVAL);
158 }
159 
160 /*
161  * vmspace_munmap(id, addr, len)
162  *
163  * unmap memory within a VMSPACE.
164  */
165 int
166 sys_vmspace_munmap(struct vmspace_munmap_args *uap)
167 {
168 	struct vkernel *vk;
169 	struct vmspace_entry *ve;
170 
171 	if ((vk = curproc->p_vkernel) == NULL)
172 		return (EINVAL);
173 	if ((ve = vkernel_find_vmspace(vk, uap->id)) == NULL)
174 		return (ENOENT);
175 	return(EINVAL);
176 }
177 
178 /*
179  * vmspace_mcontrol(id, addr, len, behav, value)
180  *
181  * madvise/mcontrol support for a vmspace.
182  */
183 int
184 sys_vmspace_mcontrol(struct vmspace_mcontrol_args *uap)
185 {
186 	struct vkernel *vk;
187 	struct vmspace_entry *ve;
188 	vm_offset_t start, end;
189 
190 	if ((vk = curproc->p_vkernel) == NULL)
191 		return (EINVAL);
192 	if ((ve = vkernel_find_vmspace(vk, uap->id)) == NULL)
193 		return (ENOENT);
194 
195 	/*
196 	 * This code is basically copied from sys_mcontrol()
197 	 */
198 	if (uap->behav < 0 || uap->behav > MADV_CONTROL_END)
199 		return (EINVAL);
200 
201 	if (VM_MAXUSER_ADDRESS > 0 &&
202 		((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
203 		return (EINVAL);
204 #ifndef i386
205         if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
206 		return (EINVAL);
207 #endif
208 	if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
209 		return (EINVAL);
210 
211 	start = trunc_page((vm_offset_t) uap->addr);
212 	end = round_page((vm_offset_t) uap->addr + uap->len);
213 
214 	return (vm_map_madvise(&ve->vmspace->vm_map, start, end,
215 				uap->behav, uap->value));
216 }
217 
218 /*
219  * Red black tree functions
220  */
221 static int rb_vmspace_compare(struct vmspace_entry *, struct vmspace_entry *);
222 RB_GENERATE(vmspace_rb_tree, vmspace_entry, rb_entry, rb_vmspace_compare);
223 
224 /* a->start is address, and the only field has to be initialized */
225 static int
226 rb_vmspace_compare(struct vmspace_entry *a, struct vmspace_entry *b)
227 {
228         if ((char *)a->id < (char *)b->id)
229                 return(-1);
230         else if ((char *)a->id > (char *)b->id)
231                 return(1);
232         return(0);
233 }
234 
235 static
236 int
237 rb_vmspace_delete(struct vmspace_entry *ve, void *data)
238 {
239 	struct vkernel *vk = data;
240 
241 	RB_REMOVE(vmspace_rb_tree, &vk->vk_root, ve);
242 	vmspace_free(ve->vmspace);
243 	kfree(ve, M_VKERNEL);
244 	return(0);
245 }
246 
247 static
248 struct vmspace_entry *
249 vkernel_find_vmspace(struct vkernel *vk, void *id)
250 {
251 	struct vmspace_entry *ve;
252 	struct vmspace_entry key;
253 
254 	key.id = id;
255 	ve = RB_FIND(vmspace_rb_tree, &vk->vk_root, &key);
256 	return (ve);
257 }
258 
259 /*
260  * Manage vkernel refs, used by the kernel when fork()ing or exit()ing
261  * a vkernel process.
262  */
263 void
264 vkernel_hold(struct vkernel *vk)
265 {
266 	++vk->vk_refs;
267 }
268 
269 void
270 vkernel_drop(struct vkernel *vk)
271 {
272 	KKASSERT(vk->vk_refs > 0);
273 	if (--vk->vk_refs == 0) {
274 		RB_SCAN(vmspace_rb_tree, &vk->vk_root, NULL,
275 			rb_vmspace_delete, vk);
276 		kfree(vk, M_VKERNEL);
277 	}
278 }
279 
280