FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_unix.c
1 /* $NetBSD: uvm_unix.c,v 1.36.2.1 2007/01/04 19:41:46 bouyer 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 1.36.2.1 2007/01/04 19:41:46 bouyer Exp $");
54
55 #include "opt_pax.h"
56
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/proc.h>
60 #include <sys/resourcevar.h>
61
62 #include <sys/mount.h>
63 #include <sys/sa.h>
64 #include <sys/syscallargs.h>
65
66 #ifdef PAX_MPROTECT
67 #include <sys/pax.h>
68 #endif /* PAX_MPROTECT */
69
70 #include <uvm/uvm.h>
71
72 /*
73 * sys_obreak: set break
74 */
75
76 int
77 sys_obreak(struct lwp *l, void *v, register_t *retval)
78 {
79 struct sys_obreak_args /* {
80 syscallarg(char *) nsize;
81 } */ *uap = v;
82 struct proc *p = l->l_proc;
83 struct vmspace *vm = p->p_vmspace;
84 vaddr_t new, old;
85 int error;
86
87 old = (vaddr_t)vm->vm_daddr;
88 new = round_page((vaddr_t)SCARG(uap, nsize));
89 if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
90 return (ENOMEM);
91
92 old = round_page(old + ptoa(vm->vm_dsize));
93
94 if (new == old)
95 return (0);
96
97 /*
98 * grow or shrink?
99 */
100
101 if (new > old) {
102 vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE;
103 vm_prot_t maxprot = UVM_PROT_ALL;
104
105 #ifdef PAX_MPROTECT
106 pax_mprotect(l, &prot, &maxprot);
107 #endif /* PAX_MPROTECT */
108
109 error = uvm_map(&vm->vm_map, &old, new - old, NULL,
110 UVM_UNKNOWN_OFFSET, 0,
111 UVM_MAPFLAG(prot, maxprot,
112 UVM_INH_COPY,
113 UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
114 UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
115 if (error) {
116 uprintf("sbrk: grow %ld failed, error = %d\n",
117 new - old, error);
118 return (error);
119 }
120 vm->vm_dsize += atop(new - old);
121 } else {
122 uvm_deallocate(&vm->vm_map, new, old - new);
123 vm->vm_dsize -= atop(old - new);
124 }
125 return (0);
126 }
127
128 /*
129 * uvm_grow: enlarge the "stack segment" to include sp.
130 */
131
132 int
133 uvm_grow(struct proc *p, vaddr_t sp)
134 {
135 struct vmspace *vm = p->p_vmspace;
136 vsize_t nss;
137
138 /*
139 * For user defined stacks (from sendsig).
140 */
141 #ifdef __MACHINE_STACK_GROWS_UP
142 if (sp < (vaddr_t)vm->vm_minsaddr)
143 #else
144 if (sp < (vaddr_t)vm->vm_maxsaddr)
145 #endif
146 return (0);
147
148 /*
149 * For common case of already allocated (from trap).
150 */
151 #ifdef __MACHINE_STACK_GROWS_UP
152 if (sp < USRSTACK + ctob(vm->vm_ssize))
153 #else
154 if (sp >= USRSTACK - ctob(vm->vm_ssize))
155 #endif
156 return (1);
157
158 /*
159 * Really need to check vs limit and increment stack size if ok.
160 */
161 #ifdef __MACHINE_STACK_GROWS_UP
162 nss = btoc(sp - USRSTACK);
163 #else
164 nss = btoc(USRSTACK - sp);
165 #endif
166 if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
167 return (0);
168 vm->vm_ssize = nss;
169 return (1);
170 }
171
172 /*
173 * sys_oadvise: old advice system call
174 */
175
176 /* ARGSUSED */
177 int
178 sys_ovadvise(struct lwp *l, void *v, register_t *retval)
179 {
180 #if 0
181 struct sys_ovadvise_args /* {
182 syscallarg(int) anom;
183 } */ *uap = v;
184 #endif
185
186 return (EINVAL);
187 }
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