xref: /netbsd-src/sys/uvm/uvm_unix.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: uvm_unix.c,v 1.32 2005/12/11 12:25:29 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
5  * Copyright (c) 1991, 1993 The Regents of the University of California.
6  * Copyright (c) 1988 University of Utah.
7  *
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * the Systems Programming Group of the University of Utah Computer
12  * Science Department.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *      This product includes software developed by Charles D. Cranor,
25  *	Washington University, the University of California, Berkeley and
26  *	its contributors.
27  * 4. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
44  *      @(#)vm_unix.c   8.1 (Berkeley) 6/11/93
45  * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
46  */
47 
48 /*
49  * uvm_unix.c: traditional sbrk/grow interface to vm.
50  */
51 
52 #include <sys/cdefs.h>
53 __KERNEL_RCSID(0, "$NetBSD: uvm_unix.c,v 1.32 2005/12/11 12:25:29 christos Exp $");
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/proc.h>
58 #include <sys/resourcevar.h>
59 #include <sys/vnode.h>
60 
61 #include <sys/mount.h>
62 #include <sys/sa.h>
63 #include <sys/syscallargs.h>
64 
65 #include <uvm/uvm.h>
66 
67 /*
68  * sys_obreak: set break
69  */
70 
71 int
72 sys_obreak(struct lwp *l, void *v, register_t *retval)
73 {
74 	struct sys_obreak_args /* {
75 		syscallarg(char *) nsize;
76 	} */ *uap = v;
77 	struct proc *p = l->l_proc;
78 	struct vmspace *vm = p->p_vmspace;
79 	vaddr_t new, old;
80 	int error;
81 
82 	old = (vaddr_t)vm->vm_daddr;
83 	new = round_page((vaddr_t)SCARG(uap, nsize));
84 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
85 		return (ENOMEM);
86 
87 	old = round_page(old + ptoa(vm->vm_dsize));
88 
89 	if (new == old)
90 		return (0);
91 
92 	/*
93 	 * grow or shrink?
94 	 */
95 
96 	if (new > old) {
97 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
98 		    UVM_UNKNOWN_OFFSET, 0,
99 		    UVM_MAPFLAG(UVM_PROT_READ | UVM_PROT_WRITE, UVM_PROT_ALL,
100 				UVM_INH_COPY,
101 				UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
102 				UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
103 		if (error) {
104 			uprintf("sbrk: grow %ld failed, error = %d\n",
105 				new - old, error);
106 			return (error);
107 		}
108 		vm->vm_dsize += atop(new - old);
109 	} else {
110 		uvm_deallocate(&vm->vm_map, new, old - new);
111 		vm->vm_dsize -= atop(old - new);
112 	}
113 	return (0);
114 }
115 
116 /*
117  * uvm_grow: enlarge the "stack segment" to include sp.
118  */
119 
120 int
121 uvm_grow(struct proc *p, vaddr_t sp)
122 {
123 	struct vmspace *vm = p->p_vmspace;
124 	vsize_t nss;
125 
126 	/*
127 	 * For user defined stacks (from sendsig).
128 	 */
129 	if (sp < (vaddr_t)vm->vm_maxsaddr)
130 		return (0);
131 
132 	/*
133 	 * For common case of already allocated (from trap).
134 	 */
135 	if (sp >= USRSTACK - ctob(vm->vm_ssize))
136 		return (1);
137 
138 	/*
139 	 * Really need to check vs limit and increment stack size if ok.
140 	 */
141 	nss = btoc(USRSTACK - sp);
142 	if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
143 		return (0);
144 	vm->vm_ssize = nss;
145 	return (1);
146 }
147 
148 /*
149  * sys_oadvise: old advice system call
150  */
151 
152 /* ARGSUSED */
153 int
154 sys_ovadvise(struct lwp *l, void *v, register_t *retval)
155 {
156 #if 0
157 	struct sys_ovadvise_args /* {
158 		syscallarg(int) anom;
159 	} */ *uap = v;
160 #endif
161 
162 	return (EINVAL);
163 }
164