uvm_unix.c revision 1.45 1 /* $NetBSD: uvm_unix.c,v 1.45 2014/09/05 05:36:49 matt 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. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
39 * @(#)vm_unix.c 8.1 (Berkeley) 6/11/93
40 * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
41 */
42
43 /*
44 * uvm_unix.c: traditional sbrk/grow interface to vm.
45 */
46
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: uvm_unix.c,v 1.45 2014/09/05 05:36:49 matt Exp $");
49
50 #include "opt_pax.h"
51
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/proc.h>
55 #include <sys/resourcevar.h>
56
57 #include <sys/mount.h>
58 #include <sys/syscallargs.h>
59
60 #ifdef PAX_MPROTECT
61 #include <sys/pax.h>
62 #endif /* PAX_MPROTECT */
63
64 #include <uvm/uvm.h>
65
66 /*
67 * sys_obreak: set break
68 */
69
70 int
71 sys_obreak(struct lwp *l, const struct sys_obreak_args *uap, register_t *retval)
72 {
73 /* {
74 syscallarg(char *) nsize;
75 } */
76 struct proc *p = l->l_proc;
77 struct vmspace *vm = p->p_vmspace;
78 vaddr_t nbreak, obreak;
79 int error;
80
81 mutex_enter(&p->p_auxlock);
82 obreak = (vaddr_t)vm->vm_daddr;
83 nbreak = round_page((vaddr_t)SCARG(uap, nsize));
84 if (nbreak == 0
85 || ((nbreak - obreak) > p->p_rlimit[RLIMIT_DATA].rlim_cur
86 && nbreak > obreak)) {
87 mutex_exit(&p->p_auxlock);
88 return (ENOMEM);
89 }
90
91 obreak = round_page(obreak + ptoa(vm->vm_dsize));
92
93 if (nbreak == obreak) {
94 mutex_exit(&p->p_auxlock);
95 return (0);
96 }
97
98 /*
99 * grow or shrink?
100 */
101
102 if (nbreak > obreak) {
103 vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE;
104 vm_prot_t maxprot = UVM_PROT_ALL;
105
106 #ifdef PAX_MPROTECT
107 pax_mprotect(l, &prot, &maxprot);
108 #endif /* PAX_MPROTECT */
109
110 error = uvm_map(&vm->vm_map, &obreak, nbreak - obreak, NULL,
111 UVM_UNKNOWN_OFFSET, 0,
112 UVM_MAPFLAG(prot, maxprot,
113 UVM_INH_COPY,
114 UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
115 UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
116 if (error) {
117 #ifdef DEBUG
118 uprintf("sbrk: grow %#"PRIxVADDR" failed, error = %d\n",
119 nbreak - obreak, error);
120 #endif
121 mutex_exit(&p->p_auxlock);
122 return (error);
123 }
124 vm->vm_dsize += atop(nbreak - obreak);
125 } else {
126 uvm_deallocate(&vm->vm_map, nbreak, obreak - nbreak);
127 vm->vm_dsize -= atop(obreak - nbreak);
128 }
129 mutex_exit(&p->p_auxlock);
130
131 return (0);
132 }
133
134 /*
135 * uvm_grow: enlarge the "stack segment" to include sp.
136 */
137
138 int
139 uvm_grow(struct proc *p, vaddr_t sp)
140 {
141 struct vmspace *vm = p->p_vmspace;
142 vsize_t nss;
143
144 /*
145 * For user defined stacks (from sendsig).
146 */
147 #ifdef __MACHINE_STACK_GROWS_UP
148 if (sp < (vaddr_t)vm->vm_minsaddr)
149 #else
150 if (sp < (vaddr_t)vm->vm_maxsaddr)
151 #endif
152 return (0);
153
154 /*
155 * For common case of already allocated (from trap).
156 */
157 #ifdef __MACHINE_STACK_GROWS_UP
158 if (sp < USRSTACK + ctob(vm->vm_ssize))
159 #else
160 if (sp >= USRSTACK - ctob(vm->vm_ssize))
161 #endif
162 return (1);
163
164 /*
165 * Really need to check vs limit and increment stack size if ok.
166 */
167 #ifdef __MACHINE_STACK_GROWS_UP
168 nss = btoc(sp - USRSTACK);
169 #else
170 nss = btoc(USRSTACK - sp);
171 #endif
172 if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
173 return (0);
174 vm->vm_ssize = nss;
175 return (1);
176 }
177
178 /*
179 * sys_oadvise: old advice system call
180 */
181
182 /* ARGSUSED */
183 int
184 sys_ovadvise(struct lwp *l, const struct sys_ovadvise_args *uap, register_t *retval)
185 {
186 #if 0
187 /* {
188 syscallarg(int) anom;
189 } */
190 #endif
191
192 return (EINVAL);
193 }
194